Missed Concepts from all Full Lengths part 2
Absolute threshold vs Just noticeable difference
AT: what volume you start to notice a sound. JND: How much you have to turn up the volume to notice the volume changing. Also notice that both AT and JND are defined by the level where you get 50% CORRECT HITS.
Abasia
Abasia is the inability to walk, possibly due to some psychological shock or trauma.
How aldesterone works?
Aldosterone works by increasing sodium absorption in the distal convoluted tubule and collecting duct of the nephron, which drives water absorption. Aldosterone also increases excretion of potassium and hydrogen ions in the urine.
Granulosa cells
Granulosa cells are follicular cells closely associated with the developing female oocyte (egg). They function to convert thecal androgens to estradiol prior to ovulation. After ovulation, they give rise to the corpus luteum and begin producing high levels of progesterone.
Sweating and temperature
The evaporation of liquid dissipates body heat, helping to lower the body's temperature and keep it from overheating. In a dry climate, the low humidity allows water to evaporate more easily, increasing sweating. That increased sweating helps keep the body cool.
Agents of socialization lists
The factors that drive and have the most influence over our socialization, known as agents of socialization, change throughout our lives. When we are children, the primary drivers of socialization are our parents and family life. When we are teenagers, our social circles have a strong influence on our socialization. By the time we are adults, the workplace, as well as media, can have a strong effect on how we develop our habits.
Facors that affect socialization
The factors that drive and have the most influence over our socialization, known as agents of socialization, change throughout our lives. When we are children, the primary drivers of socialization are our parents and family life. When we are teenagers, our social circles have a strong influence on our socialization. By the time we are adults, the workplace, as well as media, can have a strong effect on how we develop our habits.
The false consensus effect
The false consensus effect means that people tend to overestimate how common their behavior is and assume that others do the same things they do.
Feminization of poverty
The feminization of poverty is the trend of women making up more of the poor in the United States. This is directly related to more and more single women heading up households. According to census data, poor families headed by single women made up 52% in 2011 as compared to 25% in 1960
ETC (Electron transport chains)
The final major process of aerobic respiration is oxidative phosphorylation, through which the majority of aerobically-derived ATP is synthesized. This process begins by passing electrons through a series of chemical reactions, known as the electron transport chain (ETC), to a final electron acceptor, oxygen. This is the only time in eukaryotic aerobic respiration where oxygen is directly required. These reactions take place in specialized proteins where the energy from NADH and FADH2 is used up, molecular oxygen is reduced into water, and approximately 30-36 ATP are created from ADP and inorganic phosphate.
Mitochondrial genome
upon penetration of the egg, the sperm mitochondria fall apart and not replicated when divisions begin
Virus Mutation Rate
viruses undergo rapid mutation because they lack many of the DNA repair mechanisms found in higher-order organisms. Therefore, the likelihood of viral mutation >> likelihood of mammalian mutation.
Vitamin D and calcium
vitamin D plays a crucial role in the regulation of serum calcium and phosphate levels. Vitamin D exists in multiple forms, not all of which are relevant for calcium regulation. Cholecalciferol is the inactive form of vitamin D3, which is processed to form calcitriol, the biologically active form that affects calcium and phosphate levels. Calcitriol has a similar function to PTH in that it increases serum calcium levels, but it does so primarily through a different mechanism: it promotes the absorption of Ca2+ from the gastrointestinal tract.
Attitude: cognitive
way an individual thinks about something, justifying for the other two components (ex. snakes can be dangerous)
Identity shift effect
when an individual's state of harmony is disrupted by a threat of social rejection, the individual will often conform to the norms of the group and start to experience internal conflict
Hybridization
when two nucleic acid strands bind to form a double-stranded structure, the process is termed hybridization, or annealing. Like denaturation, annealing is also a step of the PCR cycle, although annealing takes place at a lower temperature (around 68°C). Hybridization also occurs in many biological processes; for example, short single-stranded RNA molecules termed small interfering RNA (siRNA) can hybridize with mRNA in a process that induces gene silencing. The siRNA-mRNA hybrid is recognized as an abnormal double-stranded RNA and is enzymatically cleaved, preventing its translation.
Enzyme temperature and pH
while the optimum pH value varies greatly from one enzyme to another, the optimum temperature for enzymes is normally 37 °C.
Self-censorship (Irving Janis's Groupthink)
withholding of opposing views Illusion of unanimity: false sense of agreement within the group
working memory
working memory is involved in reasoning and comprehension
Golgi complex
Proteins are processed for transport to the cell membrane in the golgi complex
Suppose the RNA strand shown below is a segment of viral genomic RNA. Using this RNA as a template, the enzyme reverse transcriptase would produce which of the following nucleotide polymers? 5' GGAUCCUGAAC 3'
5' GTTCAGGATCC 3'
Coordinate Covalent Bonding
A coordinate bond is a covalent bond in which both electrons come from the same atom, referred to as a ligand. It is usually formed by the bonding of a ligand, acting as a Lewis base, to a metal ion, forming a complex.
Derealization Disorder
A derealization disorder is where they feel people or objects in the external world are unreal.
Molecular and Electronic Geometry
A distinction is sometimes made between molecular geometry, which only takes into account the shape formed by the actual bonds that an atom makes, and electronic geometry, which also takes into account lone pairs. Thus, we could say that NH3 has a tetrahedral electronic geometry but a trigonal pyramidal molecular geometry.
Increase the rate of pyruvate
1. An increase of substrate that precede it or decrease of substrate that follow it...
High altitudes adaptation
1. Increased tidal volume 2. Increased secretion of erythropoietin 3. Inhaling more air than normal
Theory of emotions
1. The James-Lange theory is a theory of emotion in which individuals first experience a physiological sensation, then perceive this sensation as a type of emotion, as shown below: 2. The Cannon-Bard theory describes perception as consisting of separate, simultaneous emotional and physiological reactions. 3. The Schachter-Singer theory states that there is a physiological reaction and a cognitive label.
Weber test
A Weber test has a patient report a sound that ideally should be heard equally on both sides. In an affected patient, if the defective ear hears the Weber tuning fork louder, the finding indicates a conductive hearing loss in the defective ear. This is very similar to a diagnostic application of Weber's law.
Capacitor
A basic capacitor consists of two metal plates separated by a layer of insulating material called a dielectric. Capacitance is the ability to store charge and is calculated as C = ɛ0A/d, where A is the area of the plates and d is the distance between them. When two conducting plates are connected to a battery, electrons move towards one plate. The positive plate loses electrons as well, and both plates eventually have equal and opposite charge, +Q and −Q. When a capacitor is fully charged, the capacitor has charge Q. We can relate the charge, capacitance, and voltage across the plates using the equation Q = VC (remember the home shopping network?). The voltage in this equation is the maximum potential difference that can be applied before the insulation of the dielectric breaks down. The electrical potential energy stored in the capacitor can also be related via the equations E = ½ QV = ½ CV2. Once fully charged, the capacitor can discharge a current across the circuit until the capacitor is "emptied" of all the stored charge. The MCAT may ask you to compare the difference in terms of charging when a battery is connected (V is constant) or disconnected (Q is constant). Finally, capacitors can be combined in series (common path) or in parallel (common origin and destination, different path). Capacitors in series combine like resistors in parallel (1/Ceq = 1/C1 + 1/C2...) while capacitors in parallel combine like resistors in series (Ceq = C1 + C2...).
Micheal addition
A carbanion attacks an alpha-beta unsaturated carbonyl compound
Cell Diffferentiation
A cell differentiate into a specialized cell through epigenetic mechanism, leaving DNA sequence unaltered. Epigenetic mechanism such as methylation or changes in cell-to-cell communication are the primary way in which a stem cell differentiates into a specialized cell
Epigenetic mechanisms
A cell differentiates into a specialized cell through epigenetic mechanism. Epigenetic mechanisms such as methylation or changes to cell-tocell communication are the primary way in which a stem cell differentiates into a specialized cell.
Reduction potential and oxidizing properties
A compound with a high reduction potential will be highly oxidative. Hence, these distorted complexes will be responsible for oxidations
Conditioned stimulus
A conditioned stimulus is one that naturally does not evoke a response, but through association with an unconditioned stimulus, can eventually cause subjects to respond in a similar manner. For example, say that the participants heard a bell each time they received an injection. If, over time, the bell alone started to promote a physiological reaction, then the bell would be a conditioned stimulus.
Confounding Variables (CV)
A confounding variable is one that affects or correlates with both the independent and dependent variables in a proposed relationship;
Molecular vs electronic geometry
A distinction is sometimes made between molecular geometry, which only takes into account the shape formed by the actual bonds that an atom makes, and electronic geometry, which also takes into account lone pairs. Thus, we could say that NH3 has a tetrahedral electronic geometry but a trigonal pyramidal molecular geometry.
Double-crossover event
A double-crossover event is one in which chromosomal arms of homologous chromosomes cross over in two different places along the arm. This results in a section in the middle of each chromosome being exchanged. A simplified schematic of a single- vs. a double-crossover event is shown below.
Family group
A family group is generally determined either by birth, adoption, or marriage, joining people of different ages and sexes through strong emotional ties. A family group is typically united by blood (familial relationship) or law (marriage, adoption). In contrast, a peer group includes people of similar ages, statuses, and with similar interests, who have all chosen to join the group. Whereas a family group is not self-selected, a peer group is. A peer group can provide individuals feelings of belonging and friendship.
Reinforcement Schedules
A fixed-ratio schedule is when the behavior is reinforced after a specific number of responses. For example, a rat gets a treat every third push of a lever. Variable-ratio schedules occur when behavior is reinforced after an average, but unpredictable, number of responses. For example, a rat treat dispenser could be set to dispense a treat after an average of 1 out of every 10 presses, but the exact number of presses between rewards will vary. Fixed-interval schedules occur when behavior is reinforced after a specific amount of time has passed. An example would be semi-monthly paydays. Variable-interval schedules occur when behavior is reinforced after an average, but unpredictable, amount of time has passed. Of these methods, variable-ratio schedules are generally considered to be the most effective.
Context effects on perception
A given stimulus may trigger radically different perceptions, partly because of our differing perceptual set, but also because of the immediate context
Higher Ka and acidity
A higher Ka is associated with stronger acidity. Adding electron-withdrawing functional groups (like fluorine atoms) provides inductive stabilization of the conjugate base by pulling electron density away from the negatively-charged position (shown below). This stabilization increases the acidity of the original compound. Inductive effects increase if the electron-withdrawing groups are closer to the acid and if more of them are present.
Logarithm basics
A logarithm is simply the inverse of an exponent. That is, if 10A = B, then log10B = A. A numerical example would be that 102 = 100, so log10(100) = 2. Unless otherwise indicated, it can be assumed that "log" means log base 10. Some log values to be familiar with are log(0.01) = -2, log(0.1) = -1, log(1) = 0, log(3) ≈ 0.5, log(10) = 1, and log(100) = 2, from which you can predict log values for larger powers of 10.
Mediating variable (mediator)
A mediating variable is one that provides an explanatory link between the independent and dependent variables. In the context of the question stem, this would imply the presence of a relationship with the following structure: female employment → family planning programs → fertility.
Moderator vs mediating variable
A mediating variable is one which explains the relationship between two other variables. Here, insurance coverage connects patient race and physician prescriptions. A moderator variable is one that influences the strength of a relationship between two other variables, and a mediator variable is one that explains the relationship between the two other variables. As an example consider the relation between social status and frequency of testicular self-exams. Age might be a moderator variable, in that the relation between social status and testicular self-exam might be stronger for older men and less strong or nonexistent for younger men. Education might be a mediator variable in that it explains why there is a relation between self-exam and social status
Membrane protein
A membrane protein will have a hydrophobic region that is embedded within the lipid bilayer and a hydrophilic region that interacts with either the cytosol or the extracellular, aqueous environment
Recovered memory
A memory from a real event that was encoded, stored, but not retrieved for a long period of time until some later event brings it suddenly to consciousness
major depressive disorder
A mental health disorder characterized by persistently depressed mood or loss of interest in activities, causing significant impairment in daily life. The symptoms persist at least 2 weeks or more
Moderating Variables
A moderating variable is one that affects the intensity of the relationship between an independent variable and a dependent variable,
A natural experiment
A natural experiment is one in which the independent variable is not manipulated artificially but rather changes naturally. Then, these alterations can be used to monitor its impact upon the dependent variable.
Pi bond
A pi bond is formed by the side-to-side overlap of two p orbitals
A power analysis
A power analysis is a statistical calculation performed before a study to determine the minimum sample size needed for the study to have enough power. In other words, it determines the minimum number of participants you need to have in your study. While the researchers may use a power test prior to beginning their study, it will not give them the information they want about screening efficacy and outcome.
Primary vs Secondary group
A primary group features direct interaction between members with close and intimate relationships made that tend to last a long period of time. Families, close groups of friends, and teams can be examples of primary groups. A secondary group features superficial interaction between members, with weak and not-so-intimate relationships made that tend to not last very long. A group of students working on a project and a group of coworkers at a temporary summer job can be example of secondary groups.
Prion
A prion is an abnormally folded protein that induces a normally folded version of the protein to also adopt the abnormal structure, which is often deleterious
A prosthetic group
A prosthetic group; which is a non-protein cofactor that is tightly bound to an enzyme and is necessary for its function.
Protein isoform
A protein isoform is any of several different forms of the same protein, which typically have similar functions but different amino acid sequences. Amino acid sequencing could thus reveal whether the multiple bands shown on IEF are due to different isoforms of protein A.
Psychodynamic model
A psychodynamic model would show how relationship experiences can affect subsequent relationships.
How to use hybridization formation
A quick guide to identifying the orbital hybridization of a molecule is to determine the number of regions of electron density around the atom. A region of electron density is defined as either a bond (single, double, or triple) or a lone pair of electrons. Two regions yield a hybridization of sp (common in cases of triple bonds or central atoms with two double bonds). Having three regions of electron density is associated with sp2 hybridization, and having four regions yields sp3 hybridization.
Quick guide for hybridization
A quick guide to identifying the orbital hybridization of a molecule is to determine the number of regions of electron density around the atom. A region of electron density is defined as either a bond (single, double, or triple) or a lone pair of electrons. Two regions yield a hybridization of sp (common in cases of triple bonds or central atoms with two double bonds). Having three regions of electron density is associated with sp2 hybridization, and having four regions yields sp3 hybridization.
A redemptive social movement
A redemptive social movement is radical in scope, but affects only a single individual or a small number of individuals. The changes proposed by this group would be radical because they would require significant changes to nearly every aspect of daily life and society. However, because only a few people followed this call, its impact was limited
Reducing and non reducing sds page
A reducing gel will have beta mercaptoethanol (BME) and/or DTT added to the sample before boiling, and will break any disulfide bonds in the protein. This can result in a protein with quaternary structure (multiple subunits) to yield as many bands as there are subunits in the protein. Non-reducing conditions (no BME) will not break S-S bonds. A SDS-PAGE will denature the protein, but denaturation is not the same as breaking S-S bonds. A reducing SDS gel will do both (denature and break disulfide bonds).
Reformation social movement
A reformative social movement creates minor changes, but those changes affect a large number of people
ELISA basics
A related technique is known as the enzyme-linked immunosorbent assay (ELISA). In general, ELISA uses a solid-phase enzyme immunoassay that detects the presence of an antigen. First, a sample containing an unknown amount of antigen is applied to a solid-phase supporting structure. After the antigen contained in the sample becomes attached to the solid support, a specific detection antibody is applied to, and binds with, the antigen. The antibody is then covalently linked to an enzyme directly or through a secondary antibody that is conjugated with an enzyme. Between steps, the plate is often washed with a detergent to rinse unbound proteins or antibodies. Following addition of the enzyme's substrate, a reaction occurs that produces a visualizable signal. The intensity of this signal is related to the quantity of protein antigen present in the original sample.
Hybridization DNA, RNA
A separate category of analytical techniques combines the use of hybridization (binding of complementary nucleic acid strands) and electrophoresis (movement of molecules toward a charged electrode). For the MCAT, you should be aware of Southern blotting, western blotting, and northern blotting. Southern blotting is a technique used to identify specific DNA sequences. Western and northern blots are used to identify protein and RNA sequences, respectively. In these sequences, the molecules of interest undergo gel electrophoresis to separate them by size and then are transferred to a nitrocellulose membrane that can be heated, at which point probe analysis can be performed. (The process is slightly different for western blots, where antibodies are used instead of DNA/RNA probes.)
Interkinesis
A short rest period between meiosis I and meiosis II. DNA is not replicated.
Induction
A signaling cascade in development which changes the structure or functions of developing tissues through chemical mediators
Frameshift mutation single insertion
A single insertion will alter the reading frame, impacting all of the amino acids downstream of the insertion point
Motor unit
A single somatic motor neuron innervates a group of muscle fibers called a motor unit. The action potentials delivered by the neuron will be delivered to all the fibers in the motor unit with exactly the same frequency, so the fibers will contract in synchrony.
Sleep Cycle
A sleep cycle is a complete progression through all of the stages of sleep, from Stage 1 to REM and over again. At the beginning of the night, a person spends most time in Stage 4, but as the night progresses, REM predominates, and a person may even have very brief moments of being awake. The length of the sleep cycle increases from childhood to adulthood, from about 50 minutes to 90 minutes, respectively.
Stereotype
A stereotype is an oversimplified belief about any gender, race, religion or cultural group. Stereotypes are often widely accepted and believed, but may not reflect reality. Stereotypes may be negative, such as believing that some racial groups are more prone to crime than others, or positive, such as believing that a specific racial group is "good at math."
Reducing agents for carboxylic acid
A strong reducing agent, such as LiAlH4, can reduce a carboxylic acid directly to an alcohol, while weak reducing agents such as NaBH4 will not reduce carboxylic acids at all.
Enzyme-substrate complex
A temporary complex formed when an enzyme binds to its substrate molecule(s).
Social desirability bias
A tendency to give socially approved answers to questions about oneself.
Tollens test
A test for aldehydes in which Ag+ in Tollens' reagent is reduced to metallic silver forming a "silver mirror" on the walls of the container. The carbonyl group will be oxidized to say carboxylate group.....
Token Economy
A token economy is a form of behavior modification designed to increase desirable behavior and decrease undesirable behavior with the use of tokens. Individuals receive tokens immediately after displaying desirable behavior. The tokens are collected and later exchanged for a meaningful object or privilege.
Trait vs. Type theories
A trait theorist views personality as a function of measurable personality traits, which are relatively stable patterns in though and behavior over time. A type theorist views personality more as a set of universal categories into which all individuals can be placed (e.g., extroverted, introverted, Type A personality, Type B personality).
Desmosomes (anchoring junctions)
A type of cell junction in animal cells that functions like rivets, fastening cells together into strong sheets. Intermediate filaments made of sturdy keratin proteins anchor them in the cytoplasm. They attach muscle cells to each other in a muscle.
Bureaucracy characteristics
A typical (or ideal) bureaucracy has the following defining characteristics, which were first noted by the German sociologist and political economist Max Weber: it has a formal hierarchical structure; it is managed via a set of defined, specific rules and regulations; it is organized by functional specialty, with different workers performing different, specialized tasks; it has a unified mission that is either "up-focused," that is, to serve shareholders, a board, or some other entity that empowers it, or "in-focused", that is, to serve itself through maximizing profit or maximizing market share; it is purposefully impersonal; and employment is based on technical qualifications, either advanced degrees or training.
How ADH works?
ADH increases the permeability of the collecting duct to water, thereby increasing water absorption. Thus, ADH acts to reduce the osmolarity of blood by increasing the amount of water present without changing the solute levels, whereas aldosterone does not affect osmolarity because sodium reabsorption drives water absorption.
Absolute threshold of sensation
Absolute threshold refers to the minimum intensity of a stimulus required to detect the stimulus 50% of the time.
Abstraction
Abstraction is a problem strategy that uses models
Pierre Bourdieu
According to French social scientist Pierre Bourdieu, social interaction can be understood in terms of a field, similar to a field on which a game is played, and for which there are certain rules that pertain to the field. The field is the setting in which individual agents and their social positions are located. The position of each agent in the field is a result of interaction between the specific rules of the field, agent's habitus and agent's social, economic and cultural capital.
Freud's Defense Mechanisms
According to Freud, the ego employs one or more ego defense mechanisms to unconsciously distort reality. These mechanisms include the following: Repression is the act of pushing undesired or unacceptable thoughts and urges into the unconscious. The conscious, deliberate form of repression is known as suppression or denial and is typically used to willfully forget an emotionally painful experience. Regression is the process of reverting back to behaviors that are less sophisticated and often associated with children (such as sucking one's thumb). Reaction formation is the process of repressing a feeling by outwardly expressing the exact opposite of it. For example, if you really hate a person, you might pretend to really like them. Projection is the process of attributing one's own undesired thoughts or feelings onto another person. For example, if you have resentment toward your roommate, you may instead believe that your roommate has resentment toward you. Displacement is the process of redirecting violent, sexual, or otherwise unseemly impulses from one target to another. For example, if an employee feels aggressive urges towards his abusive boss, he might displace those aggressive feelings towards his spouse when arriving home. Rationalization is the process of justifying one's behaviors, which might be socially unacceptable and impulsive, with intellectual explanations that are more acceptable. For example, you might explain your vandalism of a public wall with spray paint by saying, "Well, so many other people do it" or "Someone else would have vandalized it later anyway." Sublimation is the process of transferring unacceptable urges or impulses into more acceptable behaviors. For example, if a man has undesirable and unrequited sexual desire for a woman, he might sublimate those urges and write a poem or love song.
Oral Stage
According to Freud, the oral stage occurs from birth to 12-18 months and is characteristic of interest in oral gratification from sucking, eating, and biting.
Signal detection theory (SDT)
According to signal detection theory the detection of a stimulus is not only dependent on its strength, but also on the psychological state (tired) of the individual
symbolic interactionsim info
According to symbolic interactionsim, there are 3 core principles to communication: meaning, language and thought. These core principles lead to conclusions about the creation of a person's self and socialization into a larger community. Meaning states that humans act toward people and things according to the meanings that give to those people or things. Symbolic interactionism holds the principal of meaning to be the central aspect of human behavior. Language gives humans a means by which to negotiate meaning through symbols.
Gestalt Law
According to the principle of proximity, objects that are arranged close to each other will be perceived as forming a group. The principle of similarity states that objects that are similar to each other in terms of color or other properties will be grouped together, and the principle of closure states that people tend to infer complete shapes even if a shape is incompletely sketched out or blocked by another object. Additionally, the principle of good continuation states that we perceive intersecting objects as forming coherent wholes. The Gestalt laws are an excellent example of the distinction between sensation and perception. Sensation refers to the process by which auditory, electromagnetic, physical, and other kinds of information from the environment are converted into electrical signals within the human nervous system. Sensation provides the raw signal, communicating information, entering the nervous system through receptors in the peripheral nervous systems. Perception, as exemplified by the Gestalt laws, is the processing of this raw information. Therefore, it is sensation that gives us information from the world around us and perception that allows us to make sense of it.
Acculturation
Acculturation refers to developing the ability to interact within a dominant culture while internally preserving facets of one's own culture of origin.
Ketone bodies
Acetoacetic acid is a ketone body. Ketone bodies can be used as fuel in the brain, the heart, and muscles, but they cannot be used in the liver because it lacks the necessary enzymes to convert ketone bodies to ATP. This is because ketone bodies are produced in the liver when blood glucose is low.
Actin and myosin
Actin and myosin interact to form cross-linkages that allow the sliding of the filaments over each other in muscle contraction, which takes place through the contraction and relaxation of the sarcomere, the fundamental unit of all muscle fibers. When muscle contracts, the actin and myosin filaments slide over each other and the H-zone (myosin-only region), Z-lines (sarcomere boundaries), and I-band (actin-only region) all shrink, while the A-band (the entire myosin region) remains the same size. The opposite occurs upon muscle relaxation.
Albert Bandura's Bobo Doll Experiment
Albert Bandura, a social cognitive psychologist, famously conducted his "Bobo doll" experiments, which showed that children can display observational learning for aggressive behavior when they watch adults exhibit such behavior.
Alcohol intoxication
Alcohol intoxication primarily disrupts one's ability to form new long-term memories (anterograde amnesia). Previously stored long-term memories are not typically disrupted, nor is the individual's capacity to keep information in short-term memory for several seconds. Accordingly, F would probably not remember the incident at all in order to testify at trial, let alone a specific detail such as the color of the vehicle that struck him
Action potential (AP) basics
Action potentials are how neurons send signals to other neurons or to the neuromuscular junction. The mechanisms of action potentials involve the voltage potential difference across the neuronal cell membrane. The nerve cell maintains a resting potential of −70 mV. When the inside of the cell loses this negative potential, the cell is said to be depolarized, and when it drops to a more negative potential than −70 mV (after peaking at +40 mV in an action potential), it is said to be hyperpolarized. This resting potential is maintained by the constant action of sodium-potassium ATPase (the Na+/K+ pump), which pushes three sodium ions out of the cell for every two potassium ions it brings in. This electrochemical gradient is also maintained by the fact that the hydrophobic core of the plasma membrane does not allow ions to easily diffuse back across.
Action potential
Action potentials are how neurons send signals to other neurons or to the neuromuscular junction. The mechanisms of action potentials involve the voltage potential difference across the neuronal cell membrane. The nerve cell maintains a resting potential of −70 mV. When the inside of the cell loses this negative potential, the cell is said to be depolarized, and when it drops to a more negative potential than −70 mV (after peaking at +40 mV in an action potential), it is said to be hyperpolarized. This resting potential is maintained by the constant action of sodium-potassium ATPase (the Na+/K+ pump), which pushes three sodium ions out of the cell for every two potassium ions it brings in. This electrochemical gradient is also maintained by the fact that the hydrophobic core of the plasma membrane does not allow ions to easily diffuse back across. If the excitatory stimulus is strong enough, and the cell's resting potential is brought up to −55 mV, the cell will undergo an action potential. In the first phase of the action potential, depolarization, the sodium voltage-gated channels open and Na+ ions rush into the cell. The sudden influx of positive charges continues until the cell membrane reaches full depolarization at +40 mV, at which point the sodium channels close and potassium voltage-gated channels open. Now that the interior of the cell is positive, the potassium is pushed by both electrical potential and its own concentration gradient to rush out, causing repolarization. Repolarization continues until the cell overshoots the −70 mV level, making the cell temporarily hyperpolarized, during what is called the refractory period. Then, the sodium-potassium pumps get back to work to re-establish the resting state of the cell. Action potentials begin at the axon hillock and move down the axon towards the synapse. This action potential can either move slowly and smoothly along the cell membrane (if the cell is unmyelinated) or can jump very rapidly down the axon from one node of Ranvier to the next (if the cell is myelinated). Nodes of Ranvier refer to gaps in the myelin sheath present in myelinated neuron
Direction of action potential
Action potentials begin at the axon hillock and move down the axon towards the synapse. This action potential can either move slowly and smoothly along the cell membrane (if the cell is unmyelinated) or can jump very rapidly down the axon from one node of Ranvier to the next (if the cell is myelinated). Nodes of Ranvier refer to gaps in the myelin sheath present in myelinated neurons.
G-protein activation
Activation of the G protein promotes the dissociation of bound GDP and its exchange for GTP on the α subunit.
Protein evolving in difficult situations
Adapting to different types of denaturing environments means the protein would need to fold in different ways depending on the barriers in its path.
Telomerase addition
Addition is dependent on the enzyme telomerase. This enzyme elongates chromosomes by adding TTAGGG sequences to the end of existing chromosomes. Somatic cells do not typically use telomerase, so they senesce or "age." Conversely, if telomerase is more active, the cell will continue to grow and divide with no clear endpoint, as seen in cancer and immortal cell lines.
Other brain systems
Additional key structures in the forebrain include the amygdala, which processes memory, emotions, and decision-making; the hippocampus, which consolidates short-term memory into long-term memory; the hypothalamus, which is the major link between the nervous and endocrine systems via the pituitary gland; the pineal gland, which modulates sleep through melatonin productions; and the thalamus, which relays sense and motor signals and regulates sleep and awareness. The limbic system includes the hypothalamus, hippocampus, amygdala, and several other structures, and plays a major role in emotions, memory, and motivation. It is distinct from the mesolimbic pathway (or reward pathway), which is located in the midbrain and plays a role in addiction.
Adrenal medulla
Adrenal medulla secretes epinephrine and norepinephrine in response to short-term stress. Reactions to short-term stress are mediated by the sympathetic branch of the autonomic nervous system.
Affinal kinship
Affinal kinship, or a "kinship of affinity," exists without blood relationship, with the most common example being kinship due to marriage. In contrast, consanguineal kinship is based on blood - or genetic - relationship.
Mitosis/Meiosis
After interphase, the cell undergoes division (mitosis in non-sex/germ cells). Mitosis proceeds through prophase (where the nuclear membrane disappears, chromosomes condense, and the mitotic spindle forms), metaphase (where chromosomes line up along the metaphase plate), anaphase (where chromosome are pulled apart), and telophase/cytokinesis (where the nuclear envelope and nucleolus reappear and the cell divides). Meiosis occurs in sex/germ cells and turns a diploid (2n) parent cell into 4 haploid (n) daughter cells in a two-stage process, in which crossover between homologous chromosomes and the random allocation of maternal/paternal chromosomes to daughter cells work together to create genetic variability.
Phospholipids and triglyceride
All triglycerides contain glycerol backbone but not all phospholipds form the same
Allport's Trait Theory
Allport outlined three basic types of traits: cardinal traits, central traits, and secondary traits. Cardinal traits are those around which people organize their entire lives. For example, Steve Jobs' lifelong passion for bringing creativity and technology together fueled his life's work at Apple and Pixar.
Alpha and beta waves in sleep
Alpha waves are detected when an individual is awake, but fatigued and less than fully alert. Beta waves are emitted when an individual is awake and fully alert. The brain waves of a fully-awake person oscillate between a high-frequency, low-amplitude pattern (beta waves) and higher-amplitude, high-frequency, faster patterns (alpha waves), depending on the state of alertness. Alpha waves are more consistent (synchronous) than beta waves. When a person falls asleep, they enter the first of the four stages of sleep.
Alzheimer's disease and Huntington's disease
Alzheimer's disease is characterized by cognitive difficulties, loss of memory, disorientation, and often language problems. It is associated with amyloid plaques (sticky clumps or patches of protein surrounded by the debris of dying nerve cells in the brain) and neurofibrillary tangles (twisted remains of damaged tau proteins, which are required for normal brain function), which cause neuronal death. Huntington's disease is a fatal condition characterized by involuntary movements and dementia. It is caused by an expanded CAG repeat in the gene that encodes the huntingtin protein on chromosome 4; this causes the progressive atrophy of brain structures. This disease has autosomal dominant inheritance.
Alzheimer's disease
Alzheimer's disease is characterized by reduced acetylcholine production. Alzheimer's disease is characterized by cognitive difficulties, loss of memory, disorientation, and often language problems. It is associated with amyloid plaques (sticky clumps or patches of protein surrounded by the debris of dying nerve cells in the brain) and neurofibrillary tangles (twisted remains of damaged tau proteins, which are required for normal brain function), which cause neuronal death.
Ambivalent attachment
Ambivalent attachment occurs when the child's caregiver is inconsistent, sometimes response to the child's needs, and sometimes not. Because of this on-off effect, a child will be distressed when separated from the caregiver, but more ambivalent upon his or her return
Amides hydrolysis
Amides are normally sensitive to hydrolysis in basic media
Amines functional group??
Amines (R-NH2, R-NHR', or R-NR'R"), imines (R=NH or R=NR'), and enamines (C=C-NH2, C=C-NHR, or C=C-NRR') are nitrogen-containing compounds with medium melting/boiling points that can act as weak bases. Sulfur-containing functional groups contain the root "thio" and generally act similarly to the corresponding oxygen-containing groups.
Amino acids with ionizable side chains
Amino acids with ionizable side chains contain a third group that can carry a charge. For the two amino acids that are commonly known as acidic (glutamic and aspartic acid), this group is a carboxylic acid. For this reason, acidic amino acids contain one group that can become positive (the amino terminal) and two groups that can become negative (the side chain and terminal carboxylic acid groups). For the three basic amino acids (histidine, lysine, and arginine), the ionizable side chain group is a basic, nitrogen-containing functional group. Like the backbone amino terminal, these groups become positively-charged when protonated and neutral when deprotonated. As such, basic amino acids contain one group that can become negative (the carboxylic acid terminal) and two groups that can become positive (the terminal amine and nitrogen-containing side chain). Importantly, not all nitrogen-containing functional groups are basic. Asparagine and glutamine both contain nitrogenous side chains (specifically, amides) but are not considered basic because amides are not readily protonated.
Emotions component
Amygdala, prefrontal cortex, and hypothalamus
Limbic system
Amygdala, which processes memory, emotions, and decision-making; the hippocampus, which consolidates short-term memory into long-term memory; the hypothalamus, which is the major link between the nervous and endocrine systems via the pituitary gland; the pineal gland, which modulates sleep through melatonin productions; and the thalamus, which relays sense and motor signals and regulates sleep and awareness. The limbic system includes the hypothalamus, hippocampus, amygdala, and several other structures, and plays a major role in emotions, memory, and motivation. It is distinct from the mesolimbic pathway (or reward pathway), which is located in the midbrain and plays a role in addiction.
EEG basics
An EEG measures electrical impulses in the brain by covering the scalp with small sensors. Researchers can then present the subject with various stimuli and record which areas of the brain demonstrate increased electrical activity. Instead of measuring electrical activity, scientists can watch the level of blood flow in parts of the brain. By injecting a tracer molecule, scientists are able to image which parts of the brain are more active in response to certain stimuli. More active brain areas will see an increase in blood flow, and thus an increase in the tracer molecule.
EEG info
An EEG measures electrical impulses in the brain by covering the scalp with small sensors. Researchers can then present the subject with various stimuli and record which areas of the brain demonstrate increased electrical activity. Instead of measuring electrical activity, scientists can watch the level of blood flow in parts of the brain. By injecting a tracer molecule, scientists are able to image which parts of the brain are more active in response to certain stimuli. More active brain areas will see an increase in blood flow, and thus an increase in the tracer molecule.
Enzyme cofactors and conenzymes
An enzyme (a biological catalyst) may require another chemical compound to be present in order for it to carry out its biological functionality. In general, such "helper" molecules are known as cofactors. Cofactors can be either inorganic (with some common examples including metal ions such as Mg2+, Zn2+, and Cu+) or organic, and organic cofactors are sometimes known as coenzymes.
fMRI
An fMRI is an imaging technique that measures brain activity by detecting associated changes in blood flow.
Apparent Movement
An illusion of perceived motion across empty space
Imiide Group
An imide is two acyl groups bound to nitrogen.
In-group
An in-group is one to which a person belongs, while an out-group is a group in which one does not feel a sense of belonging. This can, but does not have to, overlap with other group categories such as family, peer, and reference groups.
Meyers-Briggs personality assessment.
An objective personality assessment measures specific personality characteristics based on a set of discrete options, such as in the Meyers-Briggs personality assessment.
Organic acid?
An organic compound must contain carbon and hydrogen in its formula. Furthermore, there must be a covalent bond between a carbon and hydrogen atom in the molecular structure. Organic acids are weak acids, generally having formulas of R-CO2H, with the acidic hydrogen bonded to an oxygen atom.
Analogous structures vs homologous structures
Analogous structures are those structures that evolved independently to carry out the same function. Thus, the wing of a bee and the wing of a bird are analogous structures. Homologous structures are those that have a similar evolutionary history, arising from the same source, even if they now have different functions. The forelimbs of mammals (human arm, walrus flipper, bat wing) would all be homologous despite their different functions. Thus, this choice correctly indicates a pair of analogous structures and then a pair of homologous structures.
Anencephaly
Anencephaly is the absence of a major portion of the brain, skull, and scalp that occurs during embryonic development. It is a cephalic disorder that results from a neural tube defect that occurs when the rostral (head) end of the neural tube fails to close, usually between the 23rd and 26th day following conception.
Aneuploidy
Aneuploidy results from having too many or too few copies of a given chromosome. This results from nondisjunction in anaphase during cell division. Having only one copy of a chromosome is known as monosomy, and having three copies is known as trisomy.
What is Aneuploidy ?
Aneuploidy results from having too many or too few copies of a given chromosome. This results from nondisjunction in anaphase during cell division. Having only one copy of a chromosome is known as monosomy, and having three copies is known as trisomy. Aneuploidy is commonly discussed as occurring in meiosis, and indeed, this is the only way for aneuploidy to be inheritable. For this reason, nondisjunction during meiosis is the cause of aneuploidies such as Down syndrome (trisomy 21) or Turner syndrome (monosomy X). However, nondisjunction during mitosis can also occur, and this is extremely common in cancer cells.
Anode and cathode
Anode is + and cathode is - in electrophoresis
PI and electrophoresis
Anode is positive and cathode is negative. The protein with lowest Pi will migrate toward the anode most and the protein with the highest PI will migrate most toward the cathode
Half-life
Another high-yield fundamental concept is half-life (t1/2), which is the time required for one-half of the parent isotopes in a sample to decay into daughter (radiogenic) isotopes.
Half-life t12
Another high-yield fundamental concept is half-life (t1/2), which is the time required for one-half of the parent isotopes in a sample to decay into daughter (radiogenic) isotopes. If we know the half-life of a material, then we can determine how much of a sample is lost (1- ½n) or remains (½n) at any given time, as expressed in the number of half-lives that have passed (n).
Diagnostic expansion
Diagnostic expansion is when a medical diagnosis is expanded to include a larger group. ADHD meets that standard
Nuclear Localization sequence
Proteins that are translocated into the nucleus usually contain a nuclear localization sequence.
Epididymis
Sperm, produced in the seminiferous tubules of the testes, completes maturation and becomes motile in the epididymis.
Amnesia
Anterograde amnesia - antero (front): trouble forming new memories Retrograde amnesia - retro (previous): existing memories are lost
Anticipatory socialization
Anticipatory socialization refers to the process by which we prepare for future changes that we anticipate. For example, a security officer who will be switching to the night shift in a few weeks may prepare by shifting his or her sleep cycle, so as to anticipate the demands of the shift change.
Apoptosis
Apoptosis or programmed cell death involves shrinking of the cell membrane and "blobbing" of the cell contents into small vesicles.
Applied Research
Applied research is designed to answer or solve practical problems.
Arteries to capillaries
Arteries branch off from each other, they develop into smaller, more numerous arterioles. The blood pressure drops quickly between the arterioles and capillaries. Capillaries are tiny, thin vessels through which erythrocytes move one at a time. They are where the main work of gas exchange happens. After moving through the capillaries, deoxygenated blood (in the systemic circulation) moves into venules, which drain into veins, which then gather into the venae cavae before returning to the heart.
Astrocytes
Astrocytes are star-shaped cells found only in the central nervous system. The primary function of astrocytes is to maintain the proper chemical environment for action potential conduction and neuron signaling.
Arteries facts
Arteries carry high-pressure blood and therefore have thick muscular walls. They can also constrict and dilate, depending on the needs of the body. This can be used in thermoregulation, in which vasoconstriction of the arteries near the skin is used to conserve heat in a cold environment while vasodilation of those arteries is used to dissipate excess heat. Vasodilation can also be used to supply more oxygenated blood (and more energy) to specific body tissues in response to neurological control.
Arteries sturcture
Arteries carry high-pressure blood and therefore have thick muscular walls. They can also constrict and dilate, depending on the needs of the body. This can be used in thermoregulation, in which vasoconstriction of the arteries near the skin is used to conserve heat in a cold environment while vasodilation of those arteries is used to dissipate excess heat. Vasodilation can also be used to supply more oxygenated blood (and more energy) to specific body tissues in response to neurological control.
Air passageway
As air enters our body, it travels either through the nostrils (also known as the nares) or the oral cavity. The air then travels down through the pharynx, which is located at the back of the mouth and is also part of the digestive system. Air then continues past the epiglottis into the larynx, which contains the vocal cords. It then moves through the trachea, and the bronchi then split off from the bottom of the trachea
Precipitation and crystallization
As solute is added to a solvent, the solution is considered saturated when the maximum amount of solute that can be dissolved has been added. Upon heating, more solute can be dissolved in the solution, and then upon slowly cooling the solution, the same concentration of solute will remain dissolved in what is now considered a supersaturated solution. Crystals can form in supersaturated solutions with the addition of a small amount of solute, which creates a nucleation site for solute to precipitate and form a crystal. This process is called crystallization.
Solubility
As solute is added to a solvent, the solution is considered saturated when the maximum amount of solute that can be dissolved has been added. Upon heating, more solute can be dissolved in the solution, and then upon slowly cooling the solution, the same concentration of solute will remain dissolved in what is now considered a supersaturated solution. Crystals can form in supersaturated solutions with the addition of a small amount of solute, which creates a nucleation site for solute to precipitate and form a crystal. This process is called crystallization.
crystaliation
As solute is added to a solvent, the solution is considered saturated when the maximum amount of solute that can be dissolved has been added. Upon heating, more solute can be dissolved in the solution, and then upon slowly cooling the solution, the same concentration of solute will remain dissolved in what is now considered a supersaturated solution. Crystals can form in supersaturated solutions with the addition of a small amount of solute, which creates a nucleation site for solute to precipitate and form a crystal. This process is called crystallization.
Frequency shift up and down
As the object moves up and slows down, the frequency shift is negative and falls to zero at the peak of the object's flight; as the object falls, the shift becomes increasingly positive.
Cleavage formation
As the zygote travels to the uterus, it undergoes a series of mitotic cell divisions known as cleavage. Once the zygote has cleaved into a mass of 16 cells by three to four days after fertilization, it is known as the morula. By three to five days after fertilization, the morula develops some degree of internal structure and becomes a blastocyst, with a fluid-filled cavity in the middle known as the blastocoel. The blastocyst implants in the uterine endometrium and further differentiates into the gastrula. The gastrula has three layers: the ectoderm, the mesoderm, and the endoderm. These layers eventually go on to form specific organs and components in the body.
First versus zero order kinetics enzyme?
At low substrate concentrations, the reaction approximates first-order kinetics, as described above. In contrast, at very high substrate concentrations (where the enzyme is nearly or entirely saturated), the reaction approximates zero-order kinetics, since reaction rate ceases to depend on substrate concentration.
Atrial natriuretic peptide
Atrial natriuretic peptide (ANP; also known as atrial natriuretic factor [ANF]) is a hormone that the endocrine system uses to deal with the problem of excess blood volume. Essentially, it is the opposite of aldosterone. It is released in response to high blood volume and decreases sodium reabsorption in the distal convoluted tubule and the collecting duct, as well as increasing the glomerular filtration rate and inhibiting aldosterone release.
How Atrial natriuretic peptide works?
Atrial natriuretic peptide (ANP; also known as atrial natriuretic factor [ANF]) is a hormone that the endocrine system uses to deal with the problem of excess blood volume. Essentially, it is the opposite of aldosterone. It is released in response to high blood volume and decreases sodium reabsorption in the distal convoluted tubule and the collecting duct, as well as increasing the glomerular filtration rate and inhibiting aldosterone release.
Attribution theory
Attribution theory explains the way a person uses information to develop causal explanations
Attribution theory
Attribution theory relates to the ways in which people attempt to explain various behaviors and events.
Avoidant attachment
Avoidant attachment refers to when a child's caregiver provides little to no response to the child's needs, effectively providing no safe base. Children in this situation are likely to show no preference between the caregiver and a total stranger. As such, they will show little to no distress when separated from a caregiver, and little to no elation upon his or her return.
Gram positive and Gram negative
Bacteria are separated into Gram positive and Gram negative classes based on how they respond to Gram staining. Both Gram positive and Gram negative bacteria contain peptidoglycan in their cell wall, but only Gram negative bacteria have both an inner and an outer membrane
Binary fission
Bacteria reproduce through a process known as binary fission, which involves the following steps: replication, in which the chromosome is duplicated while the cell grows; segregation and growth of a new cell wall, in which the chromosomes are pulled towards different sides of the cell and the cell envelope begins to grow towards the middle of the cell; and finally, the separation of two daughter cells.
Bacteriophages
Bacteriophages are viruses whose host cells are bacteria. Instead of entering the cell completely, they inject their genetic material into their host through a syringe-like structure known as a tail sheath. Retroviruses are a distinct class of single-stranded RNA viruses, including HIV, that use an enzyme known as reverse transcriptase to synthesize DNA from their RNA genome.
Lytic vs lysogenic structures
Bacteriophages have two distinct life cycles: lytic and lysogenic. During the lytic cycle, the bacteriophage essentially works to replicate at full speed, making full use of the host cell's machinery. Eventually, the host cell is filled with virions to the point that it bursts or lyses, and a tremendous number of new virions spill out into the environment. Alternately, in the lysogenic cycle, bacteriophages can integrate themselves into the host genome, at which point they are referred to as a prophage or a provirus. In response to environmental signals, the prophage can re-emerge from the host genome and resume a lytic cycle. Non-bacteriophage viruses (e.g., those that infect humans) can exhibit a dormant stage that is similar to the lysogenic cycle. Examples of viruses with a prominent dormant stage include HIV and herpesvirus.
Self-awareness
Self-awareness is the "peak" level of consciousness, which signifies perception of the autobiographical character of a person's life experience.
lytic vs lysogenic cycle
Bacteriophages have two distinct life cycles: lytic and lysogenic. During the lytic cycle, the bacteriophage essentially works to replicate at full speed, making full use of the host cell's machinery. Eventually, the host cell is filled with virions to the point that it bursts or lyses, and a tremendous number of new virions spill out into the environment. Alternately, in the lysogenic cycle, bacteriophages can integrate themselves into the host genome, at which point they are referred to as a prophage or a provirus. In response to environmental signals, the prophage can re-emerge from the host genome and resume a lytic cycle. Non-bacteriophage viruses (e.g., those that infect humans) can exhibit a dormant stage that is similar to the lysogenic cycle. Examples of viruses with a prominent dormant stage include HIV and herpesvirus.
Eggs and Sperm size
Because both eggs and sperm contain a haploid number of chromosomes and therefore they are most similar with respect to their genome size.
why diabetes patient has ketoacidosis??
Because lack of insulin means lack of glucose in liver cells, halting the Krebs cycle and causing an overabundance of acetyl-CoA, resulting in ketogenesis and ketoacidosis.
Exchange-rational choice theory
Believes that decisions are made by rational beings who have weighed all aspects of the problem, and who the proceed to make the rational choice
Bernoulli's equation
Bernoulli's equation indicates that when height is constant (as in a horizontal pipe system), an increase in velocity corresponds to a decrease in pressure, and vice versa. A final important relationship is given by the continuity equation (v1A1 = v2A2). This equation states that within a closed system, the flow rate of a liquid is constant, which indicates that the velocity of the fluid (v) is inversely proportional to the cross-sectional area that it is flowing through.
Bernoulli's principle
Bernoulli's principle's has two underlying assumptions: incompressibility and non-viscosity of the fluid. These assumptions are not true of blood (or of any real fluid), so blood vessels don't follow Bernoulli's principle. As blood moves from arteries to capillaries, both pressure and velocity drops.
Why fats produced so much energy?
Beta-oxidation can produce very large amounts of ATP, which is connected to the fact that fats are a form of long-term energy storage in the body. For instance, the beta-oxidation of palmitic acid (a saturated fatty acid with 16 carbons) yields approximately 106 ATP.
What is Beta-oxidation?
Beta-oxidation is a process in which fatty acids are broken down into acetyl-CoA, which can be fed into the citric acid cycle (similarly to the effects of glycolysis and the pyruvate dehydrogenation complex). Beta-oxidation also generates the electron carriers NADH and FADH2, which produce energy in the electron transport chain. This process is known as beta-oxidation because the beta carbon of each fatty acid is oxidized to a carbonyl group (C=O). It occurs in the mitochondria in eukaryotic cells.
Beta Oxidsation
Beta-oxidation is a process in which fatty acids are broken down into acetyl-CoA, which can be fed into the citric acid cycle (similarly to the effects of glycolysis and the pyruvate dehydrogenation complex). Beta-oxidation also generates the electron carriers NADH and FADH2, which produce energy in the electron transport chain. This process is known as beta-oxidation because the beta carbon of each fatty acid is oxidized to a carbonyl group (C=O). It occurs in the mitochondria in eukaryotic cells. The basic logic of beta-oxidation is to chop up extended fatty acid chains into two-carbon units of acetyl-CoA. Step 1 of beta-oxidation involves forming a C=C double bond between the alpha and beta carbons of the carbonyl group at the head of the acyl-CoA molecule. This is coupled to the formation of FADH2. Then, in step 2, an -OH group is added to the beta carbon. The C-OH bond on the beta carbon is oxidized to C=O in step 3, and NADH is formed. Then, in step 4, the molecule is broken up, yielding an acetyl-CoA group and a shorter acyl-CoA group. This process is easiest to visualize with a saturated fatty acid with an even number of carbons, but special enzymes exist to handle unsaturated fatty acid and odd numbers of carbons. Beta-oxidation can produce very large amounts of ATP, which is connected to the fact that fats are a form of long-term energy storage in the body. For instance, the beta-oxidation of palmitic acid (a saturated fatty acid with 16 carbons) yields approximately 106 ATP
Construct validity
Construct validity refers to how well a given assessment (a survey, a test, etc.) actually measures what it claims to measure— whether it has been properly constructed to measure the relevant thing.
Bacterial growth phase
Binary fission can take place very quickly, and it is easy for bacteria to exhaust the resources available to them in a given setting. The bacterial growth curve describes this process. First, when bacteria are introduced to a new environment, they adapt to it during the lag phase, which takes place before appreciable growth. After adapting to the environment, they embark on an exponential growth process, known as the exponential or log phase. Eventually, the environment stops being able to sustain exponential growth, and growth ceases in the stationary phase. Finally, the resources in the environment are exhausted completely and the bacteria die in the death phase.
Bipolar I and II
Bipolar I is characterized by both severe manic and depressive episodes that tend to last several weeks. Mood swings can also be accompanied by hallucinations and delusions. Bipolar II is similar to bipolar I, but the "up" moods do not typically reach full-on mania.
Bipolar disorders
Bipolar disorders have been shown to be highly heritable and are associated with increased levels of norepinephrine and serotonin in the brain. Bipolar I disorder can be diagnosed with a single manic episode and does not require a major depressive episode. Bipolar II disorder requires at least one hypomanic episode and one major depressive episode.
MMJOR HORMONES AND THEIR FUNCTIONS
Blood glucose levels are primarily regulated by insulin and glucagon. Insulin promotes the transport of glucose from the bloodstream into cells, thereby reducing blood glucose levels. Glucagon promotes gluconeogenesis, increasing blood glucose levels when they dip to become too low. Serum calcium concentrations are regulated by parathyroid hormone and vitamin D3, which increase Ca2+ levels, and calcitonin, which decreases Ca2+ levels. Fluids are regulated by aldosterone and antidiuretic hormone, which promote fluid retention, and atrial natriuretic protein, which promotes fluid excretion. The stress response, involving increased blood glucose and sympathetic nervous system activation, is mediated by cortisol for long-term stress and by epinephrine for short-term stress. Thyroid hormone increases the basal metabolic rate, and the sex hormones estrogen and testosterone contribute to the development of secondary sex characteristics.
Type I and II diabetes
Both type I and type II diabetes, untreated, come down to poor glucose uptake. If cells are unable to uptake glucose, they will signal for more glucose to be produced, assuming blood sugar is low. The excess glucose will eventually be flushed out of the system, but since the glucose is not being taken up by the cells to metabolize, glucose and ketone bodies will keep being produced and keep being flushed out of the system. It's incredibly damaging to the body tissues; however, one effect is weight loss, which operates very much like liposuction on the microscopic scale. Fat is being taken out and flushed out of the body, rather than needing to be "burned" metabolically first.
Bottleneck effect
Bottleneck effect in genetics is when a large population is quickly and dramatically reduced in the percentage of viable individuals.
Pranayama
Breath control, consisting of conscious inhalation, retention and exhalation. Breathing is the essential element of all yoga.
Buffer and pH
Buffers resist pH changes best when the pH values are at or near the pKa value for the acid/base used, because that is when the conjugate acid and base have equal concentrations. Optimal buffering occurs when the pH is within approximately 1 pH unit from the pKa value of the system. The pH of a buffer solution can be calculated using the Henderson-Hasselbalch equation: pH = pKa + log [conjugate base] / [acid].
Buffer resist how?
Buffers resist pH changes best when the pH values are at or near the pKa value for the acid/base used, because that is when the conjugate acid and base have equal concentrations. Optimal buffering occurs when the pH is within approximately 1 pH unit from the pKa value of the system. The pH of a buffer solution can be calculated using the Henderson-Hasselbalch equation: pH = pKa + log [conjugate base] / [acid].
Buffer solution basics
Buffers work because the concentrations of the weak acid and its salt are large compared to the number of protons or hydroxide ions added or removed. When protons are added to the solution from an external source, some of the bicarbonate in the buffer is converted to carbonic acid, using up the protons added; when hydroxide ions are added to the solution, protons are dissociated from some of the carbonic acid in the buffer, converting it to bicarbonate and replacing the protons lost.
What is capcitor?
Capacitors have several medical applications (e.g. defibrillators) and are used to store charge and electrical potential energy, precluding the need for large batteries in electrical components. A basic capacitor consists of two metal plates separated by a layer of insulating material called a dielectric. Capacitance is the ability to store charge and is calculated as C = ɛ0A/d, where A is the area of the plates and d is the distance between them.
CBT
CBT first addresses maladaptive behaviors through behavior therapy to systematically modify a person's behavior. This is followed by sessions designed to foster cognitive change, through self-assessments
Carbon di oxide and blood
CO2 is the major waste product of metabolism in the human body. The bicarbonate equilibrium reaction is crucial for understanding the physiology of CO2: CO2 + H2O ⇌ H2CO3 ⇌ HCO3− + H+. The enzyme carbonic anhydrase converts CO2 to H2CO3 much faster than would otherwise be possible. Then, H2CO3 dissociates to HCO3− + H+, which is noteworthy for two reasons. First, HCO3− is charged and highly water-soluble, so it can easily be transported in the blood. Second, H+ directly acidifies the blood. Thus, a high concentration of H+, corresponding to a low pH, indicates that extensive metabolism has taken place in an area and that more O2 is necessary, which ties into the allosteric regulation of hemoglobin discussed above.
How does CO2 transport?
CO2 is the major waste product of metabolism in the human body. The bicarbonate equilibrium reaction is crucial for understanding the physiology of CO2: CO2 + H2O ⇌ H2CO3 ⇌ HCO3− + H+. The enzyme carbonic anhydrase converts CO2 to H2CO3 much faster than would otherwise be possible. Then, H2CO3 dissociates to HCO3− + H+, which is noteworthy for two reasons. First, HCO3− is charged and highly water-soluble, so it can easily be transported in the blood. Second, H+ directly acidifies the blood. Thus, a high concentration of H+, corresponding to a low pH, indicates that extensive metabolism has taken place in an area and that more O2 is necessary, which ties into the allosteric regulation of hemoglobin discussed above.
CT scan
CT machines use computer processing to take many X-ray measurements from multiple different angles, generating images that can be used for diagnosis. CT scans can provide high-resolution images, but unlike fMRI, CT is not useful for imaging processes in progress.
CT scan (computed tomography)
CT scans use X-rays, but unlike a typical single two-dimensional X-ray film, CT machines use computer processing to take many X-ray measurements from multiple different angles, generating images that can be used for diagnosis. CT scans can provide high-resolution images, but unlike fMRI, CT is not useful for imaging processes in progress.
CT scan vs X-ray
CT scans use X-rays, but unlike a typical single two-dimensional X-ray film, CT machines use computer processing to take many X-ray measurements from multiple different angles, generating images that can be used for diagnosis. CT scans can provide high-resolution images, but unlike fMRI, CT is not useful for imaging processes in progress.
When Action potential induces muscle contraction
Ca2+ is released into the cytosol and then it binds to troponin complex
Muscle contractions
Calcium Ca2+ is the main ion responsible for allowing for muscle contractions by binding troponin to move tropomysin away from the myosin-binding sites on actin. Calcium is stored in the sarcoplasmic reticulum.
Calcium and PTH
Calcium plays a key role in multiple physiological functions, most notably in bones, neurotransmitter release, muscle contractions, and as a second messenger within the cell. The body must maintain serum Ca2+ levels within very tight ranges, and the primary hormones that do so are parathyroid hormone (PTH) and calcitonin.
Capillaries facts
Capillaries are tiny, thin vessels through which erythrocytes move one at a time. They are where the main work of gas exchange happens. After moving through the capillaries, deoxygenated blood (in the systemic circulation) moves into venules, which drain into veins, which then gather into the venae cavae before returning to the heart.
Carl Jung (1875-1961)
Carl Jung was another major contributor to psychoanalytic theory. Among his many contributions, Jung described three primary conflicts of personality that further define a person: extraversion vs. introversion, sensing vs. intuiting, and thinking vs. feeling.
Checkpoints
Cell cycle progression requires a sequence of processes, with later events dependent on the completion of earlier ones. This dependency ensures that each cell division accurately replicates the genome and transmits it to daughter cells. Checkpoints control the cell's progress through the cell cycle, and ensure that key processes such as DNA replication and DNA damage repair are completed before the cell cycle is allowed to progress into the next stage. Checkpoints also ensure that both daughter cells receive the same number of chromosomes and that daughter cells are genetically identical to the parents.
Allport central and secondary traits
Central traits are defining characteristics of a person that can be easily inferred from that person's behavior. Central traits of Steve Jobs might be that he was short-tempered or brutally honest. Finally, secondary traits are those that only occur sometimes, particularly when a person is in a certain social situation. To continue the same example, Steve Jobs' secondary traits might include a tendency for showmanship when he was talking about an Apple product onstage.
What is contrifugation?
Centrifugation utilizes a rapidly spinning apparatus to separate particles by density. More dense particles, such as cells, gravitate toward the bottom of the spun tube, while less dense substances remain at the top in a liquid termed the supernatant. This liquid can then be poured off, and further separation or analysis can be conducted.
Amygdala and fear
Certain emotions are associated with specific biological structures and processes; for example, fear is associated with increased activity in the amygdala, a limbic system structure found in the temporal lobes of the brain.
Cis-trans isomerism
Cis-trans isomerism on the MCAT most frequently involves alkene bonds. Rotation about pi bonds is restricted, meaning that two different groups of atoms attached to each carbon of the C=C bond can be arranged in different ways to give different molecules. These atoms or groups can be given priorities, with atoms with higher atomic numbers given higher priorities. If the highest-priority groups for each carbon are on the same side of the molecule, that molecule is denoted as the cis or Z isomer. If they are on opposite sites, the isomer is trans or the E isomer. Cis-trans isomers generally have similar chemical but different physical properties.
Cocaine
Cocaine is a stimulant it would have a physiological effect similar to stress and hence glucose metabolism is expected to increase.
Construct validity info
Construct validity refers to how well a given assessment (a survey, a test, etc.) actually measures what it claims to measure— whether it has been properly constructed to measure the relevant thing.
Cholesterol and temperature
Cholesterol has a bidirectional impact on membrane fluidity dependent upon temperature. At low temperatures, the membrane can become too rigid, but cholesterol interferes with close packing of the phospholipids. At high temperatures, cholesterol stabilizes the membrane and raises its melting point.
Chymotrypsin
Chymotrypsin preferentially cleaves the peptide bonds next to large hydrophobic amino acids
Capacitors in circuit?
Circuits can also contain capacitors, which store charge in two physically separated components. The charge stored by a capacitor is a function of its capacitance and voltage, as expressed by the equation Q = VC. When capacitors are connected in series, their capacitance adds reciprocally, like how resistance adds for resistors in parallel. When capacitors are connected in parallel, their capacitance adds directly, like resistors in series
Capacitors
Circuits can also contain capacitors, which store charge in two physically separated components. The charge stored by a capacitor is a function of its capacitance and voltage, as expressed by the equation Q = VC. When capacitors are connected in series, their capacitance adds reciprocally, like how resistance adds for resistors in parallel. When capacitors are connected in parallel, their capacitance adds directly, like resistors in series.
Cochrane reviews
Cochrane reviews are systematic reviews of primary research in human health care and health policy and are currently the highest standard in evidence-based health care. They investigate the effects of interventions for prevention, treatment and rehabilitation.
Cognitive Biases
Cognitive biases are ways in which our perceptions and judgments systematically differ from reality. They are generally thought to be unavoidable features of our cognitive system, and may in some cases be adaptive. The closely related concept of heuristics refers to mental shortcuts or simplified iterations of principles that can help us make decisions, but can also lead to poor judgment. The representativeness heuristic is the tendency to make decisions about actions or events based upon our standard representations of those events. The closely related availability heuristic is the tendency to make decisions about how likely an action or event is based upon how readily available similar information is in our memories. Belief bias is the tendency that people have to judge things based not upon sound logic, but upon already held beliefs. Confirmation bias is a tendency that people have to focus on information that is in agreement with the beliefs they already have, rather than the information that is contrary to those beliefs. Another set of biases relate to how we interpret our and others' behavior. The fundamental attribution error refers to the tendency to place less importance on the import of a situation or context on behavior, and instead place undue emphasis on dispositional or internal qualities in order to explain behavior. In other words, we have a tendency to think that people are how they act. Moreover, we often blame our own actions on external situations but the actions of others on personality. This is called the actor-observer bias. Similarly, self-serving bias is the tendency people have to credit their successes to themselves and their failures either to the actions of others or to situations. Biases can also relate to perceptions of group belonging, as in the in-group bias where people are biased towards those viewed as being part of their in-group. Biases can also play a role in responses to questionnaires; for instance, social desirability bias refers to the tendency that people have to give socially approved responses to questions in the context of research.
Collagen
Collagen, which is found in tendons, forms connective ligaments within the body, and gives extra support to the skin. Collagen is a triple helix formed by three proteins that wrap around one another. Many collagen molecules are cross-linked together in the extracellular space to form collagen fibrils to provide structural support for the cell
Collagen basics
Collagen, which is found in tendons, forms connective ligaments within the body, and gives extra support to the skin. Collagen is a triple helix formed by three proteins that wrap around one another. Many collagen molecules are cross-linked together in the extracellular space to form collagen fibrils to provide structural support for the cell
Transcription factors
Collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription.
Dissociative Disorders: Dissociative Amnesia
Comes back over time, sometimes with loss of memory or all sense of identity and identifying information, is often linked/tied to a certain event. Sometimes with dissociative fugue.
Competitive inhibition
Competitive inhibition is when the inhibitor directly competes with the substrate for the active site on the enzyme. This increases Km since it now takes more substrate to ensure half of the active sites are occupied. If enough substrate is supplied, it will outcompete the inhibitor; therefore, Vmax does not change, although more substrate is needed to reach it.
compliance and persuation
Compliance is when an individual changes his or her behavior in response to a direct request, usually from a person or group that does not actually have authority to enforce that change. Techniques of persuasion are often used by advertisers to achieve compliance from consumers, which in this context means for the consumers to buy a product. Persuasion is a form of social influence in which an individual or group (the audience) is encouraged to adopt an idea, attitude, or course of action. In contrast to coercive methods, which actively threaten or intimidate the audience to achieve the desired goal, persuasion is non-compulsory.
Concave mirror
Concave mirror actually brings real image and bring the light rays at a single point...
Conditioned memory
Conditioned memory is a type of memory that is formed based on your associations between two things. For example, if your professor rings a bell at the end of the exam, you will remember the bell as the sign that the exam is over.
What is conjugation?
Conjugation is a special case of resonance that occurs when three or more adjacent p-orbitals are aligned with each other, forming not just a π bond, but a π system. Electrons can delocalize throughout that π system. For the purposes of the MCAT, conjugation can be associated with structures containing alternating single and double bonds in carbon chains. An important characteristic of compounds with conjugated systems is that they absorb ultraviolet (UV) light, and can therefore be well visualized using UV spectroscopy.
Construct Validity
Construct validity refers to how well a given assessment (a survey, a test, etc.) actually measures what it claims to measure— whether it has been properly constructed to measure the relevant thing.
Increased volume?
Correspondingly, increases in the amount of fluid present in the system manifest as increased blood volume (because more water is present in the blood plasma), increased blood pressure (more blood volume means more pressure against the walls of the blood vessels), and decreased blood osmolarity (the same solutes are present, but more solvent is available).
Cortisol and gluconeogenesis
Cortisol helps the body to maintain the continuous supply of blood sugar needed to sustain a stress response by upregulating gluconeogenesis and mobilizing free fatty acids and amino acids from body stores to be metabolized. This makes more glucose available, which is necessary for proper brain function during times of stress because the brain's only energy source is glucose. If cortisol release continues for too long a period, the healthy functioning of white blood cells can be inhibited, making the immune system weaker and thus the body more susceptible to illness and infection.
Counterconditioning
Counterconditioning is a classical conditioning process in which a previously conditioned association between stimulus and response is changed in favor of a new one.
Cross-sectional studies
Cross-sectional studies investigate a population at a single point in time, looking for predictive relationships among variables. A limitation of cross-sectional designs is that they can show correlations, but not causation, because looking at changes over time is necessary to assess whether a cause-and-effect relationship is present.
Cultural assimilation
Cultural assimilation is the process by which a particular group's culture begins to resemble that of another. Take for example Italian immigrants to New York City: having left Italy and taken up residence in the bustling city, immigrants began to take on qualities of New York culture. Inversely, people already in New York began to incorporate elements of Italian culture, such as eating pizza. Typically, the four factors that measure completeness of assimilation are geographic distribution, intermarriage, language acquisition, and socioeconomic status. Assimilation can be slowed by the development of cultural or ethnic enclaves, that is, neighborhoods or areas with a high concentration of people from one distinct culture or ethnicity.
Cultural capital def
Cultural capital encompasses non-financial factors that lead to social mobility, such as knowledge of styles and manners of speech, appearance, and charisma. It does not include the value of social networks, though having strong social networks can help in acquiring it.
Cultural capital
Cultural capital refers to knowledge, skills, education, and similar characteristics that are used to make social distinctions and that are associated with differences in social status. T
Cultural capital info
Cultural capital refers to the degree to which an individual has traits that allow him or her to command influence within society. This concept is distinct from social capital, because social capital refers to connections or structures that facilitate those connections, whereas cultural capital describes factors like education, manner of speech, and style of dress.
Cultural Transmission
Culture is passed along from generation to generation through various childrearing practices, including when parents expose children to music.
cultural transmission
Culture is passed along from generation to generation through various childrearing practices, including when parents expose children to music.
Culture shock
Culture shock is a sense of disorientation as a person experiences an unfamiliar culture. Typically, culture shock is thought of as consisting of four phases: honeymoon, negotiation, adjustment, and adaption.
Cyclothymic disorder
Cyclothymia is a type of bipolar disorder where mood swings are milder and do not reach full-blown manic or depressive episodes
Cytotoxic T cell
Cytotoxic T lymphocytes target virus-infected cells by recognizing the viral antigen presented on the cell surface
DNA Ligase
DNA Ligase seals the nicks after the RNA primers are removed and repaired by DNA polymerase. There is only one RNA primer on the leading strand, but many on the lagging strand as the result of Okasaki fragments. Therefore, ligase would be used more often on the lagging strand
Desomsomes and cadherin
Desmosomes also involve cadherin, but in this case cadherin connects intermediate filaments to other cells. Hemidesmosomes are junctions in which integrins connect the intermediate filaments of cells to the extracellular matrix.
DNA helicase
DNA helicase separates double stranded DNA ahead of the growing replication fork, introducing superhelical tension in the DNA. This tension must be relieved in order to prevent knots from being formed in the genomic DNA
Structure of DNA
DNA is organized in a double helix of antiparallel strands, with a sugar-phosphate backbone connected by phosphodiester bonds on the outside and nitrogenous bases on the inside. DNA contains four such bases: adenine (A), cytosine (C), guanine (G), and thymine (T); RNA contains A, C, and G, but has uracil (U) in place of thymine (T). Of these, adenine and guanine are purines, which indicates that they contain two fused rings in their structures. In contrast, cytosine, thymine, and uracil are pyrimidines and contain only a single ring. Complementary base pairing dictates that adenine pairs with thymine in DNA, adenine pairs with uracil in mRNA, and cytosine pairs with guanine in both molecules. For the DNA double helix, the interior of the structure is stabilized by hydrogen bonds between base pairs (two hydrogen bonds for AT pairs and three for CG pairs), as well as hydrophobic interactions between stacked nitrogenous bases.
DNA semiconservative
DNA replication is semiconservative, which means that each strand of the original DNA molecule serves as the template for a complementary strand, with the new DNA molecule composed of an old strand and a new strand. This fact was discovered in 1958 in the Meselson-Stahl experiment, which used radiolabeling to distinguish semiconservative replication from alternate possibilities.
Summary of DNA replication
DNA replication starts at the origin of replication and involves several important enzymes. Helicase unwinds the DNA helix and separates the two strands of DNA. Single-stranded DNA-binding proteins keep the separated strands from immediately re-annealing. Primase then synthesizes a short RNA primer with a free 3' OH group that is used as the starting point for the synthesis of a new strand. DNA polymerase reads the DNA template in a 3' to 5' direction and synthesizes the complementary strand in the 5' to 3' direction. DNA gyrase, also known as DNA topoisomerase II, alleviates the supercoiling that would otherwise be created as helicase works its way down the DNA molecule. Ligase links together Okazaki fragments, which are created from the lagging strand of DNA replication.
Negative pressure
Decreased the volume of cavity
Deindividuation
Deindividuation describes how people lose their sense of self-awareness in a large group setting, which provides a high degree of arousal and a low sense of responsibility. The main factors that contribute to deindividuation are anonymity, diffused responsibility, and group size.
Deindividuation def
Deindividuation describes how people lose their sense of self-awareness in a large group setting, which provides a high degree of arousal and a low sense of responsibility. The main factors that contribute to deindividuation are anonymity, diffused responsibility, and group size.
Blood circulation from heart to whole body
Deoxygenated blood returns to the right atrium via the superior and inferior venae cavae and the coronary sinus, which drains the coronary veins. From there, it is pumped into the right ventricle through the tricuspid valve. From the right ventricle, it goes to the pulmonary arteries through the pulmonary semilunar valves. After becoming oxygenated, it is returned to the heart via the pulmonary veins, and enters the left atrium. It is pumped through the bicuspid valve from the left atrium to the left ventricle, and then the left ventricle pushes the blood into circulation (more specifically, through the aortic semilunar valves into the ascending aorta).
Blood circulation pathways
Deoxygenated blood returns to the right atrium via the superior and inferior venae cavae and the coronary sinus, which drains the coronary veins. From there, it is pumped into the right ventricle through the tricuspid valve. From the right ventricle, it goes to the pulmonary arteries through the pulmonary semilunar valves. After becoming oxygenated, it is returned to the heart via the pulmonary veins, and enters the left atrium. It is pumped through the bicuspid valve from the left atrium to the left ventricle, and then the left ventricle pushes the blood into circulation (more specifically, through the aortic semilunar valves into the ascending aorta).
Research Studies
Depending on what researchers are studying, they can either employ a cross-sectional design or an experimental design. Cross-sectional studies investigate a population at a single point in time, looking for predictive relationships among variables. A limitation of cross-sectional designs is that they can show correlations, but not causation, because looking at changes over time is necessary to assess whether a cause-and-effect relationship is present. An experimental design involves manipulating a certain variable—known as an independent variable—to see what effects it has. The measured effects are known as dependent variables. Additional types of study design exist, especially in the social sciences; of note, qualitative research focuses on analyzing experiences rather than objective metrics. In any experiment, it is important to include controls. Negative controls are treatments that are known to have no effect, and positive controls are treatments that are known to have a certain effect and can therefore be used to assess whether the experimental methodology was sound. In clinical contexts, experimental studies often use a double-blind design in which neither the subjects nor the researchers know who is receiving the treatment and who is receiving the control. In experimental design, it is important to account for confounding variables, which are external variables affecting both the independent and dependent variable. For instance, if a study analyzes the effects of stereotype bias on math performance by race, but fails to account for socioeconomic status (SES), its results may be suspect, because SES may predict math performance and be correlated with race. Moderating variables attenuate or strengthen a given relationship, and mediating variables provide an important logical link between an independent variable and a dependent variable, or outcome. Studies on humans must follow the ethical principle of informed consent, in which the subject is adequately informed about the nature of the process, and then is mentally and legally competent to give consent to it. Sample size (usually denoted with N) is simply the number of data points developed in an experiment. In the social sciences and biology, this usually means the number of people or number of organisms in the experiment. The larger the sample size, the higher the statistical power of the experiment. While more is always better, it is usually impossible to test every possible case or every possible person, so a smaller sample of the whole must be taken. Non-random sampling can introduce important sources of bias, which can limit the validity of the study.
Psychoactive drugs
Depressants cause relaxation by reducing nervous system activity. Alcohol is the most commonly used depressant. It works by stimulating the production of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter associated with reduced anxiety, and dopamine, which promotes euphoria. Alcohol slows the activity of the frontal lobe, reducing judgment and lowering inhibitions. While drinking, people can become unable to recognize the consequences of their actions, and their speech may be slurred and motor skills diminished. Opiates are derived from the poppy plant and include such drugs as morphine and codeine. Opiates cause a sense of euphoria and a decreased reaction to pain by binding to opioid receptors in the nervous system. Opiate overdose can cause death when the brain stops sending signals for respiration. After prolonged use, these drugs can cause the brain to entirely stop producing endorphins, meaning that withdrawal is very painful. Stimulants increase arousal in the nervous system, often through the release and inhibition of the reuptake of dopamine, norepinephrine, and serotonin. This effectively increases arousal, increasing heart rate and blood pressure, and creating effects of anxiety, delusions of grandeur, euphoria, hypervigilance, and decreased appetite. Hallucinogens, such as lysergic acid diethylamide (LSD) and ketamine, distort perception, enhance sensory experiences, and cause introspection, all while increasing heart rate and blood pressure, increasing body temperature, and dilating the pupils. Finally, marijuana has qualities of a stimulant, depressant, and hallucinogen. Marijuana, which is the name used for the leaves and flowers of the plants Cannabis sativa and Cannabis indica, has an active chemical called tetrahydrocannabinol (THC) which affects certain receptors in the brain. Additionally, THC increases the production of GABA and dopamine. Physiologically, THC can cause an increase in appetite, dry mouth, fatigue, eye redness, lowered blood pressure, and increased heart rate.
Psychophysical Discrimination Testing
Directly assess our perception of stimuli in relation to their true physical properties
Discrimination
Discrimination is treating people unequally on the basis of group membership.
Disorganized attachment
Disorganized attachment refers to when a child's caregiver behaves erratically and is typified by a disorganized pattern of behavior in response to the caregiver's absence and presence
Dissociative disorders
Dissociative disorders involve the disruption or breakdown of perception, identity, memory, or awareness. Individuals with these conditions feel disconnected from reality. Often, this dissociation serves to provide an unintentional escape from reality or barrier against stress from a life event.
Dissociative disorders basics
Dissociative disorders involve the disruption or breakdown of perception, identity, memory, or awareness. Individuals with these conditions feel disconnected from reality. Often, this dissociation serves to provide an unintentional escape from reality or barrier against stress from a life event.
Diverging Lens
Diverging lens produce virtual image and always reduced the images
Dopamine and serotonin
Dopamine is used in reward and motor pathways. It is particularly associated with Parkinson's disease and the loss of dopaminergic neurons in the substantia nigra. Endorphins suppress pain and can produce euphoria. Serotonin regulates mood, appetite, and sleep in the brain, with low levels associated with depressive mood disorders.
Dopamine and serotonin compare
Dopamine is used in reward and motor pathways. It is particularly associated with Parkinson's disease and the loss of dopaminergic neurons in the substantia nigra. Endorphins suppress pain and can produce euphoria. Serotonin regulates mood, appetite, and sleep in the brain, with low levels associated with depressive mood disorders.
Dopamine, Endorphines, and Serotonin
Dopamine is used in reward and motor pathways. It is particularly associated with Parkinson's disease and the loss of dopaminergic neurons in the substantia nigra. Endorphins suppress pain and can produce euphoria. Serotonin regulates mood, appetite, and sleep in the brain, with low levels associated with depressive mood disorders.
Neurotransmitters 2
Dopamine is used in reward and motor pathways. It is particularly associated with Parkinson's disease and the loss of dopaminergic neurons in the substantia nigra. Endorphins suppress pain and can produce euphoria. Serotonin regulates mood, appetite, and sleep in the brain, with low levels associated with depressive mood disorders.
Conjugated system
Double bonds separated by a single bond and it absorbs light in UV region. UV light has shorter wavelength and higher frequency than visible light, while infrared light has longer wavelength and lower frequency
Parallel processing
Due to the brain's capacity for parallel processing, information about space, time and frequency of events is automatically processed; however, conscious effort is needed to process novel information.
Effective Nuclear charge (Zeff)
Due to the presence of protons, the nucleus of an atom is always positive. The attractive force of this positively-charged nucleus on the atom's negatively-charged valence electrons is termed the effective nuclear charge (Zeff). As the number of protons in the nucleus increases from left to right across a period (or row) of the table, Zeff also increases, since each additional proton adds positive charge to the nucleus. However, Zeff is not synonymous with the number of protons held by an atom. Moving down a group, the principal quantum number of the outermost energy level increases, which effectively means that more shells of electrons are added between the nucleus and the outermost, or valence, electrons. These layers of core electrons partially shield the valence electrons from the effects of the positive charge in the nucleus. Thus, Zeff decreases as one moves down a group.
Effective nuclear charge (Zeff)
Due to the presence of protons, the nucleus of an atom is always positive. The attractive force of this positively-charged nucleus on the atom's negatively-charged valence electrons is termed the effective nuclear charge (Zeff). As the number of protons in the nucleus increases from left to right across a period (or row) of the table, Zeff also increases, since each additional proton adds positive charge to the nucleus. However, Zeff is not synonymous with the number of protons held by an atom. Moving down a group, the principal quantum number of the outermost energy level increases, which effectively means that more shells of electrons are added between the nucleus and the outermost, or valence, electrons. These layers of core electrons partially shield the valence electrons from the effects of the positive charge in the nucleus. Thus, Zeff decreases as one moves down a group.
S phase
During S phase, which follows G1 phase, all of the chromosomes are replicated. Following replication, each chromosome now consists of two sister chromatids (see figure below). Thus, the amount of DNA in the cell has effectively doubled, even though the ploidy, or chromosome count, of the cell remains at 2n. Note: Chromosomes double their number of chromatids post replication but the nuclei remains diploid as the number of centromeres and chromosomes remains unchanged. Hence, the number of chromosomes in the nucleus, which determines the ploidy, remains unchanged from the beginning to the end of the S phase.
Senescence
During cellular senescense, cells cease to divide due to the shortening of telomere length
Non-coding RNA?
Finally, non-coding RNA plays a role in gene expression. MicroRNA (miRNA) strands are single-nucleotide strands incorporated into an RNA structure with a characteristic hairpin loop, while small interfering RNA (siRNA) molecules are short and double-stranded. Both tend to be approximately 22 nucleotides in length, and silence genes by interrupting expression between transcription and translation.
Sliding filament model
During contraction, the actin and myosin filaments slide past each other through what is known as a cross-bridge cycle, in which a cross-bridge is formed between myosin and actin, and a power stroke provides the force of contraction. Immediately after a power stroke, myosin and actin are bound together, and the cycle begins again. ATP binds to the myosin head, causing a conformational change that releases it from actin. Then, a protein called tropomyosin moves back into place to block strong interactions between actin and myosin. The ATP molecule is then hydrolyzed. This is a strongly exergonic reaction and is used to move the myosin head into the "cocked position," where it can interact weakly with actin. Tropomyosin is ultimately removed by Ca2+ through a somewhat complex mechanism. At this point, the myosin head can bind tightly to actin. The power stroke then occurs via a conformational change that happens when Pi is released, resulting in a force of about 2 pN. ADP is then released and actin and myosin are essentially stuck together until another ATP binds to myosin so that the process can start again.
neurulation process
During neurulation, the notochord induces the development of the neural plate from the ectoderm. The neural plate develops further into the neural tube, eventually becoming the brain and spinal cord. Surrounding ectoderm that did not differentiate into the neural plate becomes the neural crest. These cells eventually differentiate into the supporting cells of the nervous system, such as oligodendrocytes or astrocytes.
Muscle contraction
During normal muscle contraction, ATP is required to break the bonds between the actin filament and the myosin head. After death, no new ATP is generated, so the myosin head cannot be released from the actin filament, resulting in stiffening of muscles.
Sertoli cells
During spermatogenesis, the main function of Sertoli cells is to nourish the developing sperm cells. These cells are located in the epithelial lining of the seminiferous tubules and are activated by FSH.
Typical breathing
During typical breathing, the diaphragm contracts, flattening it and increasing the volume of the intrapleural space. As a result, the lungs expand and the pressure inside them decreases. The resulting pressure differential between the lungs and the atmosphere causes air to rush in, a process termed inspiration. If the lungs are punctured, air will flow freely between the lung and the intrapleural space, and the lung will not expand (since no pressure differential can be maintained). Expansion of the thoracic cavity should still lead to some air flow into the lung, however, although it will also mix freely with the thoracic cavity's air, making it more difficult to absorb oxygen within the damaged lung while also making it harder to maintain a pressure differential with the other lung.
Dysthymia
Dysthymia is a more subtle form of depression. This mood disorder may cause feelings of sadness and perhaps pessimism,
ELISA
ELISA uses a solid-phase enzyme immunoassay that detects the presence of an antigen. First, a sample containing an unknown amount of antigen is applied to a solid-phase supporting structure. After the antigen contained in the sample becomes attached to the solid support, a specific detection antibody is applied to, and binds with, the antigen. The antibody is then covalently linked to an enzyme directly or through a secondary antibody that is conjugated with an enzyme. Between steps, the plate is often washed with a detergent to rinse unbound proteins or antibodies. Following addition of the enzyme's substrate, a reaction occurs that produces a visualizable signal.
Effective nuclear charge
ENC is increased from left to right due to the increase in positive charge in the nucleus
Effective nuclear charge and isoelectronic ion
ENC is largest for the atom that has largest positive charge or proton. The ion with the smallest radius is the one with the greatest positive charge. This is because the greater the positive charge, the greater the effective nuclear force that the outer valence electrons will experience.
Visual processing and ligt
Each eye's right visual field is projected onto the left half of the eye's retina. As the electrical signals carrying visual information travel to the occipital lobe, the first major event happens at the optic chiasm, where optical fibers from the nasal half of each retina (i.e. the half of each retina closest to an individual's nose) cross paths. In contrast, the temporal fibers (i.e. the fibers from the lateral sides of the eyes) do not cross paths. This means that once optic fibers get through the optic chiasm, the fibers corresponding to the left visual field from both eyes are projected onto the right side of the brain, and vice versa. Once they have passed through the optic chiasm, the signals goes on to eventually reach the visual processing region of the brain, the occipital lobe.
left and right visual fields
Each eye's right visual field is projected onto the left half of the eye's retina. As the electrical signals carrying visual information travel to the occipital lobe, the first major event happens at the optic chiasm, where optical fibers from the nasal half of each retina (i.e. the half of each retina closest to an individual's nose) cross paths. In contrast, the temporal fibers (i.e. the fibers from the lateral sides of the eyes) do not cross paths. This means that once optic fibers get through the optic chiasm, the fibers corresponding to the left visual field from both eyes are projected onto the right side of the brain, and vice versa. Once they have passed through the optic chiasm, the signals goes on to eventually reach the visual processing region of the brain, the occipital lobe.
Ecological models
Ecological models focus on the context of an individual, including interpersonal factors (relationships with others), social/cultural factors, and community-level factors.
What is ecological validity?
Ecological validity refers to how findings from an experimental setting can be generalized to the environmental considerations in the real world.
Edman degradation
Edman degradation is a technique used to sequence proteins via successive cleaving of terminal amino acid residues.
Egocentric bias
Egocentric bias is the tendency to overstress changes between the past and present in order to make oneself appear more worthy or competent than one actually is. According to the results from several conducted studies, individuals are also more likely to favor circumstances that are beneficial to themselves compared to those that favor the people around them.
Eicosanoids
Eicosanoids are a large family of lipids derived from arachidonic acid, a 20-carbon omega-6 polyunsaturated fatty acid with four cis double bonds. Like their parent compound arachidonic acid, eicosanoids have 20 carbons, and they have the additional characteristic feature of a five-carbon ring. The most important eicosanoids are a large family of signaling molecules known as prostaglandins, which have a diverse range of effects, including the modulation of inflammation. Additionally, thromboxanes are involved in the clotting cascade. The enzymes cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) are involved in early steps of this pathway, and are targeted therapeutically by non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin.
Electric force, F=qE
Electrical force depends on the particle's charge and the strength of the electric field experienced by the particle, not on the particle's speed.
Tight Junctions
Finally, tight junctions are found in epithelial cells. As the name suggests, the cells in tight junctions are linked very closely to each other, preventing solutes from being able to move freely from one tissue into another. A classic example is the blood-brain barrier, where the epithelial cells in blood vessels in the brain form very tight junctions that allow the close regulation of which substances from the bloodstream can enter the central nervous system. Some types of epithelial tissue have relatively few tight junctions; these are known as leaky epithelia. Examples include some parts of the kidney.
Carbacation and stability
Electron donating group will stabilize and withdrawing group will destabilize the carbacation
Acidity and basicity
Electron withdrawing group increases acidity and donating group increase basicity
Electron withdrawing and donating groups
Electron-withdrawing Electron-withdrawing groups will enhance the acidity of compounds, and donating group will decrease the acidity or increase basicity
How do electron passed in ETC?
Electrons are passed from carriers with lower reduction potential to those with higher reduction potential.
Emotional intelligence
Emotional intelligence refers to the ability to perceive, express, understand, and manage one's emotions. Emotionally intelligent people are self-aware and can delay gratification in pursuit of long-term rewards, rather than being overtaken by immediate impulses.
Endocytosis
Endocytosis is used to ingest larger materials. It is divided into pinocytosis and phagocytosis. In pinocytosis, cells engulf liquid substances, while in phagocytosis, they engulf solid particles. The basic pathway of endocytosis involves recognition of a target molecule at the plasma membrane, followed by invagination and the formation of a vesicle on the inside of the cell. Exocytosis can be thought of as endocytosis in reverse. It is used to release hormones, neurotransmitters, membrane proteins and lipids, and other materials.
Endonuclease
Endonucleases are more commonly encountered on the MCAT, and often appear within the context of restriction endonucleases, or restriction enzymes, which are enzymes used extensively in recombinant DNA technologies. In nature, endonucleases occur in prokaryotes and archaea, where they act as a defense system against invading viruses by cleaving DNA in response to specific recognition sites, corresponding to sequences of 4 to 8 bases. These recognition sites usually involve some degree of symmetry, as reflected by palindromic sequences
Why use SDS for protein?
First, proteins vary widely in their structure, or folding patterns. If we simply tried to run a mixture of proteins through a gel electrophoresis apparatus, these variations would impact the proteins' migration. Additionally, simple gel electrophoresis relies on the fact that DNA and RNA molecules contain a uniform negative charge, causing them to travel toward the positive pole of the apparatus. In contrast, proteins can have positive, negative, or neutral charges, and these charges may not be uniformly distributed throughout the molecule.
Enzyme activity depends on what?
Enzyme activity depends principally on an enzyme's intrinsic catalytic efficiency, its concentration, the initial substrate concentration, the presence of inhibitors or allosteric activators, temperature, and pH.
Epidemiology
Epidemiology is the study of how health and illnesses are distributed across populations, and social epidemiology focuses on how societal factors influence this distribution. Risk factors are any variables that increase the likelihood of having or developing a certain illness. The uneven distribution of risk factors across population results in health disparities, which can exist based on geography, gender, environment, socioeconomic status, ethnicity/race, and access to healthcare, among other variables.
Estrogen and testosterone function
Estrogen and testosterone, which are steroid hormones secreted by the ovaries and testes, respectively, are the two most important hormones involved in reproduction and the development of secondary sex characteristics. Secondary sex characteristics are sex-specific features that are not directly related to the reproductive organs; examples in humans include wider hips in females and facial hair in males. Secondary sex characteristics contribute to sexual dimorphism, or the presence of noticeable morphological differences between the sexes within a species.
Estrogen functions
Estrogen is involved in the regulation of the menstrual cycle and contributes to the development of female secondary sex characteristics, while testosterone contributes to the development of male secondary sex characteristics. Both hormones have other systemic effects, but these go beyond the scope of the MCAT. Another important steroid hormone involved in the reproductive system is progesterone, which prepares the uterus for implantation and maintains it throughout pregnancy.
RNA to RNA
Eukaryotic cells do not generate RNA from RNA, and therefore eukaryotic cells do not have enzymes that perform this function.
Eustress and Nustress
Eustress is a positive type of stress that happens when you perceive a situation as challenging, but motivating. Eustress is usually enjoyable! Neustress is a neutral type of stress. Neustress happens when you are exposed to something stressful, but it doesn't actively or directly affect you. For example, news about a natural disaster on the other side of the world may be very stressful, but your body doesn't perceive that stress as good or bad for you so you aren't affected.
Exhalation
Exhalation can be either passive or active. In passive exhalation, the simple relaxation of the diaphragm is enough to cause the lungs to contract, increasing the pressure and expelling air. However, the muscles between the ribs (internal intercostal muscles) and abdominal muscles can be used to force air out more intensely and quickly. This frequently occurs during exercise, but increased reliance on active exhalation even at rest can be a sign of respiratory disease.
Face validity
Face validity refers to the subjective perception by other experts of whether the test is relevant to its stated goals
Roles of fatty acids
Fatty acids play three crucial roles in the body: they are the constituents of complex membrane lipids, stored fat in the form of triglycerides (esters of 3 fatty acids joined together with glycerol, a 3-C triol), and the precursors for the synthesis of bioactive lipids (e.g. diacylglycerol). At physiological pH (pH 7.4), the carboxyl group is ionized, rendering fatty acids negatively charged.
Fatty acids basics
Fatty acids play three crucial roles in the body: they are the constituents of complex membrane lipids, stored fat in the form of triglycerides (esters of 3 fatty acids joined together with glycerol, a 3-C triol), and the precursors for the synthesis of bioactive lipids (e.g., diacylglycerol). At physiological pH (pH 7.4), the carboxyl group is ionized, rendering fatty acids negatively charged. The melting point of fatty acids increases as the length of the carbon tail increases. In addition, unsaturated fatty acids will have lower melting points than saturated fatty acids with the same number of carbon atoms. As a general rule, unsaturated fatty acids are liquids at room temperature while more saturated fats are solids. Fatty acids also demonstrate cis/trans isomerism. In cis fatty acids, the acyl groups are on the same side of the double bond, while in a trans fatty acid, the acyl groups are on opposite sides. Cis fats generally have higher boiling points, while trans fats have higher melting points. The lipid synthesis mechanism of the body can theoretically supply the body with near-sufficient fatty acid structures. However, the fatty acids linoleic acid and α-linolenic acid cannot be synthesized from precursors in the body, and are thus considered the essential fatty acids.
Feminist Theory
Feminist theory is a perspective that aims to understand the effects of gender and gender inequality on society. This perspective often focuses on the roles of women, who are perceived to have less power than men. This is often reflected by socioeconomic factors, as with the oft-quoted statistics about women's earning power in relation to men.
Feminist vs conflict theory
Feminist theory often appears on the MCAT in connection with conflict theory, a sociological perspective that stresses the competition for resources between different groups of people. Because certain groups can amass more resources than others, they can maintain control of these resources by creating social structures and institutions that keep others from advancing towards positions of power. These structures and institutions in turn maintain a certain social order. With respect to feminist theory, the group with relatively more control of resources is men, while women are kept in positions of less power due to existing social structures and conventions.
Intro of fertilization
Fertilization takes place in the Fallopian tube, when a sperm cell encounters a secondary oocyte. The sperm cell passes through the corona radiata, a layer of follicular cells surrounding the oocyte, and the zona pellucida, a layer of glycoproteins between the corona radiata and the oocyte. This triggers the acrosome reaction, in which digestive enzymes are released that allow the nucleus of the sperm cell to enter the egg. The secondary oocyte completes meiosis II, creating a second polar body and a mature ovum. Then, the haploid nuclei of the sperm cell and the ovum merge, creating a diploid one-cell zygote.
What is long-term memory?
Finally, information can proceed to long-term memory, which is currently theorized to have a potentially infinite capacity. Long-term memory is divided into implicit memory, also known as nondeclarative memory, and explicit memory, also known as declarative memory. Implicit (nondeclarative) memory accounts for acquired skills and conditioned responses to circumstances and stimuli. This also includes procedural memory, which accounts for motor skills and specific physical actions. The cerebellum plays a primary role in encoding implicit memories. Explicit (declarative) memory accounts for memories that we must consciously recall with effort and focus. A further division within explicit memory is between episodic memory, which accounts for our experiences, and semantic memory, which accounts for facts and concepts that we know. The hippocampus plays a primary role in encoding explicit memories.
Decrease volume?
Fluid regulation is crucial for the maintenance of life. There are two basic scenarios that the body can encounter: too little fluid and too much fluid. Having too little fluid in one's system manifests in three important ways: reduced blood volume (because relatively little water is present in the blood plasma), reduced blood pressure (a consequence of reduced blood volume—less liquid is present to exert pressure against the walls of the blood vessels), and increased blood osmolarity (the same solutes are present, but less solvent is available).
Fluid Balance in the body
Fluid regulation is crucial for the maintenance of life. There are two basic scenarios that the body can encounter: too little fluid and too much fluid. Having too little fluid in one's system manifests in three important ways: reduced blood volume (because relatively little water is present in the blood plasma), reduced blood pressure (a consequence of reduced blood volume—less liquid is present to exert pressure against the walls of the blood vessels), and increased blood osmolarity (the same solutes are present, but less solvent is available). Correspondingly, increases in the amount of fluid present in the system manifest as increased blood volume (because more water is present in the blood plasma), increased blood pressure (more blood volume means more pressure against the walls of the blood vessels), and decreased blood osmolarity (the same solutes are present, but more solvent is available). Two major hormones respond to low fluid levels by increasing fluid retention: aldosterone (the main example of a class of steroid hormones known as mineralocorticoids) and anti-diuretic hormone (ADH), a peptide hormone that is also known as vasopressin. However, these two hormones have different mechanisms. Aldosterone works by increasing sodium absorption in the distal convoluted tubule and collecting duct of the nephron, which drives water absorption. Aldosterone also increases excretion of potassium and hydrogen ions in the urine. In contrast, ADH increases the permeability of the collecting duct to water, thereby increasing water absorption. Thus, ADH acts to reduce the osmolarity of blood by increasing the amount of water present without changing the solute levels, whereas aldosterone does not affect osmolarity because sodium reabsorption drives water absorption. Atrial natriuretic peptide (ANP; also known as atrial natriuretic factor [ANF]) is a hormone that the endocrine system uses to deal with the problem of excess blood volume. Essentially, it is the opposite of aldosterone. It is released in response to high blood volume and decreases sodium reabsorption in the distal convoluted tubule and the collecting duct, as well as increasing the glomerular filtration rate and inhibiting aldosterone release.
G0 Phase
G0 phase Not all cells are continually replicated. Non-replicating cells are found in a stage of the cell cycle called G0. These cells may be quiescent (dormant) or senescent (aging or deteriorating). Such cells generally enter the G0 phase from G1. Cells may remain quiescent in G0 for an indeterminate period of time (when no more new cells are needed), only to re-enter G1 phase and begin dividing again under specific conditions. While quiescent cells may re-enter the cell cycle, senescent cells do not. One reason that cells trigger senescence is to ensure that damaged or defective DNA sequences is not passed on to daughter cells.
Aldol condensation
For the MCAT, the most important reaction involving enolates is aldol condensation. The basic mechanism involves the nucleophilic enolate ion of one aldehyde/ketone attacking the electrophilic carbonyl carbon of the other. The molecules join together, and the immediate result is an aldol—that is, a molecule that combines the features of an aldehyde (or ketone) and an alcohol—and is technically known as a β-hydroxyaldehyde or β-hydroxyketone. This simply refers to the fact that there is a single carbon separating the carbonyl and hydroxyl functional groups. This is followed by a condensation step, in which the -OH is removed through an elimination reaction catalyzed by a strong base, resulting in a compound known as an α,β-unsaturated aldehyde or ketone.
Frame-shift mutations
Frame-shift mutations are the most deleterious type of mutation to the final gene product, as every amino acid downstream of a frame-shift mutation is likely to be incorrect and, in addition, premature STOP codons will often truncate the final protein.
Charge of Amino Acids
Free amino acids contain a minimum of two groups that can become charged. The first is the carboxylic acid terminal, which exists as neutral -COOH when protonated and negatively-charged -COO− when deprotonated. The second is the amino terminal, which becomes the positively-charged -NH3+ when protonated and the neutral -NH2 when deprotonated. Note that "protonated" is not always synonymous with "positive." A protonated position can be either positive or neutral, depending on the group in question. Similarly, a deprotonated position can be either negative or neutral. Amino acids with ionizable side chains contain a third group that can carry a charge. For the two amino acids that are commonly known as acidic (glutamic and aspartic acid), this group is a carboxylic acid. For this reason, acidic amino acids contain one group that can become positive (the amino terminal) and two groups that can become negative (the side chain and terminal carboxylic acid groups). For the three basic amino acids (histidine, lysine, and arginine), the ionizable side chain group is a basic, nitrogen-containing functional group. Like the backbone amino terminal, these groups become positively-charged when protonated and neutral when deprotonated. As such, basic amino acids contain one group that can become negative (the carboxylic acid terminal) and two groups that can become positive (the terminal amine and nitrogen-containing side chain). Importantly, not all nitrogen-containing functional groups are basic. Asparagine and glutamine both contain nitrogenous side chains (specifically, amides) but are not considered basic because amides are not readily protonated. The charge pattern of amino acids changes in response to the surrounding pH. Let's consider a simple amino acid, alanine, which has a neutral side chain. At an extremely low pH, both the carboxylic acid group and the amine group will be protonated (-COOH and -NH3+, respectively), resulting in a net charge for the amino acid of +1. At an extremely high pH, very few H+ ions will be available, and both groups will be deprotonated (-COO− and -NH2), resulting in a net charge of −1. To understand what happens at an intermediate pH, consider the relevant functional groups. Carboxylic acids are weak acids, whereas amine groups are weakly basic. This means that -COOH groups are relatively "happy" to give up their extra proton and exist as carboxylate ions (-COO−), even at relatively low pH values where there is a fair amount of H+ present. In other words, a huge amount of H+ must be present to force the carboxylate ions to accept a proton. In contrast, amine groups "like" being protonated, which means that the pH must be quite high for it to be willing to give up its proton. Thus, for intermediate pH ranges, the carboxylic acid will be deprotonated (-COO−) and the amine group will be protonated (NH3+), resulting in a net charge of zero. This is the case at physiological pH.
Free radicals
Free radicals are highly reactive compounds that contain a single unpaired electron. Biologically relevant free radicals are generally unwanted byproducts of oxidative metabolism, and are known to damage DNA, leading to potentially dangerous mutations. Antioxidants, such as vitamin E, are substances that buffer the damage caused by free radicals, protecting against such mutations.
free radicals
Free radicals are molecules or atoms that contain one unpaired valence electron. As such, they typically serve as highly reactive oxidizing agents.
Frequency and refractive index
Frequency increases so also refractive index increases
fMRI basics
Functional MRI, or fMRI, trades spatial resolution for temporal resolution and allows scientists to map active parts of the brain. It does so by analyzing the differences in oxyhemoglobin and deoxyhemoglobin concentration in parts of the brain
Fundamental attribution error
Fundamental attribution error occurs when a person assigns too much weight to internal causes rather than external factors when trying to explain the cause of another person's behavior.
G proteins
G proteins are known as heterotrimers, because they are composed of three distinct α, β, and γ subunits. When bound to GDP, G proteins are inactive, but they become activated by binding to GTP. An intracellular component of the G protein receptor facilitates the exchange of a molecule of GDP for GTP at the α-subunit of the G protein. Once this takes place, the α-subunit together with the bound GTP dissociates from the β and γ subunits. At this point, the subunits of the G protein separately interact with effectors in the cell, triggering downstream signaling processes.....
GABA receptor mechanism
GABAA and GABAC receptors have GABA binding sites to which GABA will bind. Once GABA binds to these sites, chloride channels are opened and chloride ions flow down their concentration gradient into the cell
GAPDH
GAPDH is a glycolytic enzyme that catalyzes the reversible conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate. I
Game Theory
Game theory focuses on the rational behavior of interacting people. The story holds that people are rational beings who act according to their self interest.
Gap junctions
Gap junctions are formed by connexin proteins, which connect cells in a way such that diffusion can take place between them, enabling communication, without involving direct contact between the cytoplasmic fluids of each cell. Gap junctions are relatively less common, but they play certain crucial roles within the body.
Gas chromatography and mass
Gas chromatography allows us to separate mixtures by their affinity for the solid phase, while mass spectroscopy allows us to determine the molecular weight of a sample. Neither technique gives us primary sequence
Acetylation
Gene expression can also be regulated on the level of nucleosomes (i.e. chromatin and histones). Acetylation promotes transcription by attaching acetyl groups to lysine residues on histones, making them less positively-charged and causing a looser wrapping pattern that allows transcription factors to access the genome more easily.
Gene acetylation
Gene expression can also be regulated on the level of nucleosomes (i.e. chromatin and histones). Acetylation promotes transcription by attaching acetyl groups to lysine residues on histones, making them less positively-charged and causing a looser wrapping pattern that allows transcription factors to access the genome more easily.
Gene expression regulation
Gene expression can also be regulated on the level of nucleosomes (i.e. chromatin and histones). Acetylation promotes transcription by attaching acetyl groups to lysine residues on histones, making them less positively-charged and causing a looser wrapping pattern that allows transcription factors to access the genome more easily. Finally, non-coding RNA plays a role in gene expression. MicroRNA (miRNA) strands are single-nucleotide strands incorporated into an RNA structure with a characteristic hairpin loop, while small interfering RNA (siRNA) molecules are short and double-stranded. Both tend to be approximately 22 nucleotides in length, and silence genes by interrupting expression between transcription and translation.
Membrane invagination
Generally, when membranes of any kind are ruffled or invaginated, this results in an increase in cell membrane surface area. In fact, the membrane cannot attain a ruffled morphology without an increase in the lipid content of the membrane. Other examples of this trend can be seen in the inner mitochondrial membrane and the villi of the intestinal lining. In all these cases, the invaginations increase the surface area of an enclosed space (either a cell or an organ) to increase the area available for interaction with the extracellular environment. For osteoclasts, the increased surface area gives the cell more area with which to contact bone structure, secrete bone dissolving agents, and absorb the dissolved bone minerals.
Regulatory sequences (DNA)
Genes contains large regulatory sequences, such as the promoter region, that are not transcribed. However, these regulatory sequences are still considered part of the gene they help to regulate. As a result, the primary transcript will always be shorter than the gene itself.
Genetic drift
Genetic drift refers to the role of chance, in the absence of strong selective pressures, in determining the reproductive fitness of various alleles. When no strong pressure exists for a certain allele, it may randomly happen to be reproduced more or less often. These random effects can add up over the course of evolution
Me and I Mead's view
George Mead theorized that one's identity is developed through social interaction. In order to develop a self, an individual has to be able to view his- or herself through the eyes of others, which is a skill that must be learned. Mead proposed two versions of the self: the "me" and the "I." The "me" is the attitudes, roles, meanings, pressures, and values of society and others around the individual that are organized into one's social self through role-taking. The "I" is the part of the self that can be identified with desires, freedom, and creativity. Essentially, the "me" is the social self and the "I" is one's response to the "me." Through socialization, individuals learn to look at the world through others' perspectives.
Gestalt theory of perception
Gestalt psychologists believe that the "whole" of behavior constitutes more than the sum of its parts. Gestalt theory suggests that the brain superimposes meaning and organization in a top-down fashion on sensory perceptions. Neurophysiological imprints are constituent parts that make up the whole of perception and would be seen by Gestalt psychologists as incomplete. Gestalt theory suggests that perception occurs in a top-down fashion; it is not merely the result of an integration of sensory elements in a bottom-up fashion, as this would place too great an emphasis on the parts instead of the whole (c
Glial cells
Glial cells provide the neurons with nourishment, physical support, and protection. Glial cells also dispose of the waste generated when neurons die, and accelerate neural conduction by acting as an insulating sheath around certain axons, similar to a rubber coating around an electrical wire. There are three primary glial cells types in the mature human central nervous system.
Globalization
Globalization refers to the process by which the exchange of worldviews, products, services, ideas, and other cultural ideas leads to international integration. This lessens geographical constraints on businesses, ideas, and people. One of the benefits of globalization is that in-season produce can be shipped from countries across the world, where produce that is currently out of season in the U.S. is in-season. Globalization also accounts for the spread of major international businesses and increased manufacturing. As such, one of the negative effects of globalization is the pollution that this business growth brings with it.
Glucagon
Glucagon is a peptide hormone released by the alpha cells of the pancreas, and its mechanism and function are essentially the opposite of insulin. Glucagon is released in response to low glucose levels and has the effect of increasing blood glucose levels by promoting glycogenolysis and gluconeogenesis in liver cells.
How glucagon works
Glucagon is a peptide hormone released by the alpha cells of the pancreas, and its mechanism and function are essentially the opposite of insulin. Glucagon is released in response to low glucose levels and has the effect of increasing blood glucose levels by promoting glycogenolysis and gluconeogenesis in liver cells.
Neurotransmitters fact
Glutamate is an excitatory neurotransmitter and is the most common, as 90% of brain cells are responsive to glutamate. In contrast, GABA is the main inhibitory neurotransmitter of the CNS, and it hyperpolarizes cells to reduce action potential firing. Alcohol binds and activates GABA receptors (in other words, alcohol is a GABA agonist), so the effects of GABA are associated with alcohol intoxication. Glycine is another inhibitory neurotransmitter found in the spinal cord and brainstem that can work in conjunction with GABA.
Neurotransmitters glutamate
Glutamate is an excitatory neurotransmitter and is the most common, as 90% of brain cells are responsive to glutamate. In contrast, GABA is the main inhibitory neurotransmitter of the CNS, and it hyperpolarizes cells to reduce action potential firing. Alcohol binds and activates GABA receptors (in other words, alcohol is a GABA agonist), so the effects of GABA are associated with alcohol intoxication. Glycine is another inhibitory neurotransmitter found in the spinal cord and brainstem that can work in conjunction with GABA.
Neurotransmitters
Glutamate is an excitatory neurotransmitter and is the most common, as 90% of brain cells are responsive to glutamate. In contrast, GABA is the main inhibitory neurotransmitter of the CNS, and it hyperpolarizes cells to reduce action potential firing. Alcohol binds and activates GABA receptors (in other words, alcohol is a GABA agonist), so the effects of GABA are associated with alcohol intoxication. Glycine is another inhibitory neurotransmitter found in the spinal cord and brainstem that can work in conjunction with GABA. Dopamine is used in reward and motor pathways. It is particularly associated with Parkinson's disease and the loss of dopaminergic neurons in the substantia nigra. Endorphins suppress pain and can produce euphoria. Serotonin regulates mood, appetite, and sleep in the brain, with low levels associated with depressive mood disorders. Neurotransmitters can also be active in the peripheral nervous system. Most notably, acetylcholine activates muscle contraction at the neuromuscular junction. It is used in all autonomic outputs from the brain to autonomic ganglia, and in the parasympathetic nervous system for post-ganglionic connections. Serotonin regulates intestinal movement in the gastrointestinal tract, in addition to its effects in the brain. Epinephrine stimulates the fight-or-flight response, and norepinephrine is used in post-ganglionic connections in the sympathetic division of the autonomic nervous system. It also increases arousal and alertness and focuses attention.
Guconeogenesis precursors
Glycerol, Lactate, oxaloacetate, and α-ketoglutarate are used as starting materials in gluconeogenesis.
Glycogenesis
Glycogenesis is the process of building glycogen to store glucose for the future.
Glycolipids
Glycolipids are lipids with attached carbohydrate groups. They are found on the exoplasmic surface of all human cell membranes and extend from the phospholipid bilayer into the aqueous environment, where they act as recognition sites for chemicals and as cellular attachment sites
Glycolysis and Gluconeogenesis
Glycolysis is essentially the universal metabolic pathway used for energy production and is overall an exergonic reaction. Even though some steps require energy input and are endergonic, the overall reaction is exergonic. High citrate levels would inhibit glycolysis; since the Krebs cycle is essentially "full" with citrate, there is no need to continue running glycolysis and some of those carbohydrate precursors in the Krebs cycle can be used to make "new" glucose. Gluconeogenesis produces the opposite effect as glycolysis so it is tempting to say that gluconeogenesis is endergonic.However, glycolysis and gluconeogenesis are not truly reverse reactions but are competing pathways with opposite effects. The two processes involve different chemical reactions that are both overall exergonic
Glycolysis info
Glycolysis is fundamental to all forms of cellular life. It takes place in the cytosol of cells, and its main purpose is to allow cells to obtain energy from glucose regardless of whether oxygen is present. The net reaction of glycolysis is: glucose + 2 NAD+ + 2 ADP + 2 Pi → 2 pyruvate + 2 NADH + 2 ATP + 2 H2O. Glycolysis has an initial "investment phase," consuming 2 ATP, and then a "payoff phase" generating 4 ATP. Thus, the net energy gain to the cell is 2 ATP.
Glycolysis
Glycolysis is fundamental to all forms of cellular life. It takes place in the cytosol of cells, and its main purpose is to allow cells to obtain energy from glucose regardless of whether oxygen is present. The net reaction of glycolysis is: glucose + 2 NAD+ + 2 ADP + 2 Pi → 2 pyruvate + 2 NADH + 2 ATP + 2 H2O. Glycolysis has an initial "investment phase," consuming 2 ATP, and then a "payoff phase" generating 4 ATP. Thus, the net energy gain to the cell is 2 ATP. Pyruvate is a three-carbon alpha-keto acid that participates in multiple pathways in the body. In organisms that carry out aerobic metabolism, pyruvate is then converted to acetyl-CoA and fed into the citric acid cycle. The NADH produced by glycolysis is an electron carrier that can ultimately yield energy through oxidative phosphorylation. However, the NADH needs to be converted back to NAD+ for glycolysis to continue. This can happen in the electron transport chain or through fermentation. In lactic acid fermentation, which often occurs in human muscles, pyruvate is converted to lactate by lactate dehydrogenase in a reaction coupled to the conversion of NADH to NAD+. Of the 10 steps of glycolysis, step 3 is the most carefully regulated. In step 3, fructose 6-phosphate (formed in step 2) is transformed into fructose 1,6-bisphosphate by phosphofructokinase-1. This is the committed and rate-limiting step, and the major target for regulation. It involves the transfer of a phosphate group from ATP, and is the second of two steps where ATP is invested in the initial phase (step 1, where glucose → glucose 6-phosphate [G6P], is the first). Of note, step 3 takes place before the six-carbon carbohydrate chain is broken down into two three-carbon compounds. Glycolysis is upregulated when the cell needs more ATP, as signaled by relatively high concentrations of AMP/ADP or an abundance of inorganic phosphate (Pi). It is downregulated when the cell does not need more ATP, as indicated by a high level of ATP, abundant levels of NADH, or high levels of citrate (the product of the first step in the citric acid cycle). Glycolysis is also subject to negative regulation, in which certain products inhibit previous steps. Most notably, G6P, the first product of glycolysis, inhibits hexokinase, which catalyzes step 1, the conversion of glucose to G6P.
Regulation of glycolysis
Glycolysis is upregulated when the cell needs more ATP, as signaled by relatively high concentrations of AMP/ADP or an abundance of inorganic phosphate (Pi). It is downregulated when the cell does not need more ATP, as indicated by a high level of ATP, abundant levels of NADH, or high levels of citrate (the product of the first step in the citric acid cycle). Glycolysis is also subject to negative regulation, in which certain products inhibit previous steps. Most notably, G6P, the first product of glycolysis, inhibits hexokinase, which catalyzes step 1, the conversion of glucose to G6P.
Glycosidic bond
Glycosidic bonds are a key mechanism through which monosaccharides combine with each other. A glycosidic bond is formed when the anomeric carbon of one sugar reacts with a hydroxyl group in another sugar. This is a dehydration reaction, in which an H2O molecule is lost as the two monosaccharides condense to form a disaccharide
Glycosidic bonds?
Glycosidic bonds are a key mechanism through which monosaccharides combine with each other. A glycosidic bond is formed when the anomeric carbon of one sugar reacts with a hydroxyl group in another sugar. This is a dehydration reaction, in which an H2O molecule is lost as the two monosaccharides condense to form a disaccharide; as such, it is similar to how peptide bonds are formed between amino acids, although the specific functional groups involved are different (an amide is formed in a peptide bond, whereas an ether [C-O-C] is formed in a glycosidic bond). Moreover, the formation of a glycosidic bond transforms the hemiacetal or hemiketal found at the anomeric carbon into an acetal or a ketal, because the -OH group that is characteristic of a hemiacetal/hemiketal is transformed into a second -OR group, which defines an acetal/ketal.
How glycosidic bonds are formed?
Glycosidic bonds are a key mechanism through which monosaccharides combine with each other. A glycosidic bond is formed when the anomeric carbon of one sugar reacts with a hydroxyl group in another sugar. This is a dehydration reaction, in which an H2O molecule is lost as the two monosaccharides condense to form a disaccharide; as such, it is similar to how peptide bonds are formed between amino acids, although the specific functional groups involved are different (an amide is formed in a peptide bond, whereas an ether [C-O-C] is formed in a glycosidic bond). Moreover, the formation of a glycosidic bond transforms the hemiacetal or hemiketal found at the anomeric carbon into an acetal or a ketal, because the -OH group that is characteristic of a hemiacetal/hemiketal is transformed into a second -OR group, which defines an acetal/ketal.
Glycosidic bonds
Glycosidic bonds are a key mechanism through which monosaccharides combine with each other. A glycosidic bond is formed when the anomeric carbon of one sugar reacts with a hydroxyl group in another sugar. This is a dehydration reaction, in which an H2O molecule is lost as the two monosaccharides condense to form disaccharide
Starch (amylose and amylopectin)
Glycosidic bonds can be described in terms of the anomers (α or β) and specific carbons involved. Common glycosidic bonds include α(1→4), α(1→6), β(1→4), and β(1→6) bonds. Starch is composed of two main subtypes of polymers: amylose and amylopectin. Amylose is a linear polymer of glucose molecules connected by α(1→4) glycosidic bonds; it comprises about 20%-30% of starch. Amylopectin makes up the remaining 70%−80% of starch; it likewise contains glucose molecules connected by α(1→4) glycosidic bonds, but it has branches due to α(1→6) glycosidic bonds every 24−30 units. It is somewhat easier to break down than amylose.
Types of glycosidic bonds?
Glycosidic bonds can be described in terms of the anomers (α or β) and specific carbons involved. Common glycosidic bonds include α(1→4), α(1→6), β(1→4), and β(1→6) bonds. Starch is composed of two main subtypes of polymers: amylose and amylopectin. Amylose is a linear polymer of glucose molecules connected by α(1→4) glycosidic bonds; it comprises about 20%-30% of starch. Amylopectin makes up the remaining 70%−80% of starch; it likewise contains glucose molecules connected by α(1→4) glycosidic bonds, but it has branches due to α(1→6) glycosidic bonds every 24−30 units. It is somewhat easier to break down than amylose.
group polarization
Group polarization is the tendency that groups have to make decisions that are notably more extreme than the initial, individual opinions of their members. The related, but distinct, concept of groupthink refers to when a group of people has such a strong desire for harmony and individual conformity that the group makes irrational decisions.
Grouppthink
Groupthink occurs when situational pressures hinder groups from critically evaluating relevant information. A powerful leader makes groupthink more likely, and the other group members are largely complicit in the behaviors and beliefs that produce groupthink. Groups affected by groupthink wrongly believe they have followed a sound decision-making process.
Growth hormone
Growth hormone can increase blood glucose levels due to its antagonistic effects on insulin.
Drugs dependence ranking
Hallucinogens have low risk of dependence, whereas the other substances listed as possible answers carry a moderate to high risk of physical or psychological dependence
Harry Harlow
Harry Harlow examined parent/child attachment, social isolation, and dependency in rhesus monkeys.
Heart and Brain energy
Heart and brain tissues consistently use large amount of energy and mostly incapable of utilizing anerobic respiration to satisfy their energy requirements
Mesoderm
Heart, kidney, and skeletal muscle are derived from mesoderm
Heat generation in ETC
Heat generation results from uncoupled oxidative phosphorylation at the inner mitochondrial membrane
Hemoglobin
Hemoglobin, a metalloprotein, plays an essential role in gas exchange in humans. Specifically, it functions in the transport of oxygen to the body tissues and of carbon dioxide to the lungs for exhalation. Hemoglobin is found in in red blood cells (erythrocytes), which are packed full of the protein; in fact, erythrocytes contain so much hemoglobin that they have no room for - and therefore lack - a nucleus or membrane-bound organelles. Erythrocytes are produced in the bone marrow. Under low-oxygen conditions, erythrocyte production increases in response to the secretion of a kidney hormone, erythropoietin (EPO).
The largest estimates of heritability
High degrees of genetic variability within a group of individuals raised in similar environments.
Histone and DNA binding
Histones are highly alkaline and are positively charged at physiological pH, which facilitates their interaction with the highly negatively charged phosphate groups on the backbone of DNA. Modifications like acetylation of histones reduce that positive charge, making histones interact with DNA less closely, which in turn facilitates transcriptional activity.
Histones
Histones are proteins that act as spools for DNA to wind around. They are composed of various subunits known as H1, H2A, H2B, H3, and H4. The core of a histone contains two dimers of H2A and H2B and a tetramer of H3 and H4, while H1 serves as a linking unit. Approximately 200 base pairs of DNA can be wound around a histone, and the complex formed by DNA and a histone is known as a nucleosome. The phrase "beads on a string" is often associated with the appearance of nucleosomes under electron microscopy, and chromatin refers to the structure formed by many nucleosomes.
Histones structure
Histones are proteins that act as spools for DNA to wind around. They are composed of various subunits known as H1, H2A, H2B, H3, and H4. The core of a histone contains two dimers of H2A and H2B and a tetramer of H3 and H4, while H1 serves as a linking unit. Approximately 200 base pairs of DNA can be wound around a histone, and the complex formed by DNA and a histone is known as a nucleosome. The phrase "beads on a string" is often associated with the appearance of nucleosomes under electron microscopy, and chromatin refers to the structure formed by many nucleosomes.
Structure of histone
Histones are proteins that act as spools for DNA to wind around. They are composed of various subunits known as H1, H2A, H2B, H3, and H4. The core of a histone contains two dimers of H2A and H2B and a tetramer of H3 and H4, while H1 serves as a linking unit. Approximately 200 base pairs of DNA can be wound around a histone, and the complex formed by DNA and a histone is known as a nucleosome. The phrase "beads on a string" is often associated with the appearance of nucleosomes under electron microscopy, and chromatin refers to the structure formed by many nucleosomes.
Homologous recombination
Homologous recombination is the only repair mechanism for double-stranded DNA.
Horizontal mobility
Horizontal mobility is a shift within the same class.
Radioimmunoessay (RIA)
Immunoassays operate on the principle that antibodies cultured from antibody-producing cells can bind with great specificity to a protein antigen of interest. A protein in a mixture can be detected using a radioimmunoassay (RIA); in an RIA, the protein concentration can be assessed indirectly by measuring the extent to which the protein competes with a radioactively labeled standard for antibody binding sites.
Steroid Hormones
Hormones can be divided according to structure into steroid versus peptide hormones (as well as a few amino acid-derived hormones). All steroid hormones are derived from cholesterol, which means they share a four-ring lipid structure and are permeable to the cell membrane. Since steroid hormones are hydrophobic, they are typically transported throughout the body using plasma proteins in the blood. Steroid hormones are synthesized by the adrenal cortex and the gonads, in the mitochondria and smooth endoplasmic reticulum. Because they are lipophilic (i.e., hydrophobic), they cannot be stored in vesicles (since they would diffuse out easily), and are only synthesized when needed as precursors. Since steroid hormones diffuse freely through the plasma membrane due to their hydrophobicity, steroid hormone receptors are found on the inside of the cell, and these receptors form a complex with the hormone before entering the nucleus. Once inside the nucleus, the hormone-receptor complex binds to promoter regions of target genes and can stimulate or inhibit transcription of those genes. Thus, steroid hormones directly regulate gene expression in target cells. Direct gene effects take time to manifest, so steroid hormone responses are generally slower than peptide hormone responses. However, since these changes are at the genetic level, they are much longer-lasting and sometimes permanent (e.g., sex hormones and sexual differentiation). If you encounter an unknown hormone on Test Day, the suffix of the name provides some clues. Generally, steroid hormones and in -ol, -one, or -en (e.g., testosterone, cortisol, and estradiol). Many hormones relating to the reproductive system are steroid hormones. Another important steroid hormone, aldosterone, regulates fluid and salt levels, and cortisol affects blood glucose levels as part of the long-term stress response. These three functions of steroid hormones are sometimes known as the three "S's": sex, salt, and sugar. However, it is important to keep in mind that these functions are not only controlled by steroid hormones.
Calculation of pH
How acidic or basic a solution is can be expressed in terms of pH or pOH, which are defined as follows: pH = −log [H+] and pOH = −log [OH−]. For example, a solution with an H+ concentration of 10−4 M will have a pH of 4, and a solution with an OH− concentration of 10−9 M will have a pOH of 9. pH and pOH values can be estimated given a certain concentration using the following shortcut: p(N × 10−M) = (M−1).(10−N), such that a solution with an H+ concentration of 4 × 10−8 will have a pH = (8−1).(10−4) = 7.6.
Shortcut to find pH values
How acidic or basic a solution is can be expressed in terms of pH or pOH, which are defined as follows: pH = −log [H+] and pOH = −log [OH−]. For example, a solution with an H+ concentration of 10−4 M will have a pH of 4, and a solution with an OH− concentration of 10−9 M will have a pOH of 9. pH and pOH values can be estimated given a certain concentration using the following shortcut: p(N × 10−M) = (M−1).(10−N), such that a solution with an H+ concentration of 4 × 10−8 will have a pH = (8−1).(10−4) = 7.6.
Psychological Disorders
Human psychology is enormously broad, making it virtually impossible - and perhaps undesirable - to define a state of "normal" psychology. However, certain mental conditions can seriously impair a person's ability to function in professional and personal life. These conditions are termed psychological disorders, and they can be categorized into several groups. Mood disorders are characterized by the persistent, abnormal elevation and/or lowering of one's mood, which refers to a sustained, internal state of feeling or emotion. These conditions include bipolar disorders, which are marked by swings between extreme moods. These moods may include depression (a state of persistent sadness and lack of energy) and mania (a high-energy state marked by poor judgment, lack of sleep, and euphoria). Another mood disorder is major depressive disorder, which is characterized by at least one major depressive episode (a period of depression lasting at least two weeks). Anxiety disorders involve a state of excessive apprehension, worry, or panic. This state of heightened physical arousal can be unpleasant and inhibit regular functioning. While most people feel anxiety occasionally, those with anxiety disorders experience it persistently, and it adversely impacts their lives. Trauma and stress-related disorders typically arise in response to a highly stressful or traumatic life event. The most common example is post-traumatic stress disorder (PTSD), which often manifests in people who experienced warfare, sexual assault, or serious injury. PTSD can cause symptoms such as nightmares, flashbacks, and a propensity to avoid stimuli associated with the event. Somatic disorders are unified by somatic (bodily) symptoms that can cause stress and impairment to the sufferer. These symptoms generally lack an identifiable physical cause. Alternatively, the individual may be impaired by irrational fears of developing or having a disease, as in illness anxiety disorder. Schizophrenia is a psychotic disorder, meaning that sufferers experience at least one of the following symptoms: delusions, disorganized thoughts, disorganized behavior, hallucinations, catatonia, and negative symptoms. Dissociative disorders involve the disruption or breakdown of perception, identity, memory, or awareness. Individuals with these conditions feel disconnected from reality. Often, this dissociation serves to provide an unintentional escape from reality or barrier against stress from a life event. Finally, personality disorders are characterized by long-lasting, maladaptive patterns of behavior that can impair cognition, emotion, interpersonal behavior and communication, and/or impulse control.
Humans and Evolution
Humans have developed a preference for high caloric foods because they are a good source of fuel in the form of fat. Fat can sustain bodily functions through periods of time when food is scarce (a common problem throughout evolution).
HCL pH calculation
Hydrochloric acid is a strong acid and completely dissociates in aqueous solution. In this solution, the hydronium ion concentration is 10.6 M, which can be approximated as 10 M to make the math easier. The pH is the -log of the hydronium ion concentration: -log[10] = -log[101] = -1. While the typical pH range is normally thought of as ranging from 0 to 14, if the concentration of hydronium ion is greater than 1 M, negative pH values are possible. It is also possible to have pH values greater than 14, i.e. if the hydroxide concentration is greater than 1 M.
Implicit memory
Implicit memory occurs when past experiences help the performance of a task without conscious awareness of the past experiences. This fits the concept of tying one's shoes.
imprinted genes
Imprinted genes are expressed in a parent-specific manner
practice effects
Improvements in performance resulting from opportunities to perform a behavior repeatedly so that baseline measures can be obtained.
Melting points and impurities
Impurities in a solid both depress the melting point, and broaden the range over which the solid melts.
Hydrophobic interactions
Hydrophobic interactions utilize both repulsion and attraction (a push and a pull) to contribute to a protein's conformational stability. The push comes from the thermodynamically favorable shielding of hydrophobic residues afforded by their location inside the protein. The pull results from van der Waals forces between nonpolar side chains on the polypeptide, especially London dispersion forces, which are amplified in the close quarters of a hydrophobic core and produce a greater affect in larger proteins.
Inttentional blindness
Ianttentional blindness is a failing to see visible objects when attention is directed elsewhere
Symbolic culture
Ideas, beliefs, and symbols are considered to be part of symbolic or nonmaterial culture. In contrast, artifacts, art, buildings, and physical objects are part of material culture, which includes all of the physical objects used in a society.
identification
Identification refers to the acceptance of other people's ideas without thinking critically about them.
Hypertonic, hypotonic, isotonic
If a cell is placed in an environment that contains a higher concentration of solutes than the interior of the cell, we call this environment hypertonic. When a cell is placed in a hypertonic solution, the solution is relatively solute-rich, while the cell is relatively watery. Therefore, water will move from the cell into the surrounding solution to equalize the solute concentration. This will cause the cell to lose water and shrink. In contrast, when a cell is exposed to a hypotonic (lower in solute concentration) environment, water will travel from the environment into the cell, causing the cell to swell and even burst, or lyse. Finally, an environment with the same solute concentration as the cell in question is termed isotonic.
Pedigree basics
If a phenotype skips generations, it must be recessive. Individuals who are heterozygous for a recessive mutation are often referred to as carriers, because they do not manifest the condition but can pass it on to their children, depending on their mate's genotype. X-linked mutations are usually recessive for the purposes of the MCAT, and X-linked recessive conditions affect males more often. This is because females inherit one X chromosome from their mother and one from their father, while males only get their single X chromosome from their mother. Since males only have one X chromosome, having a single mutated allele will suffice to manifest a recessive mutation.
Why male gets more X- recessive disease?
If a phenotype skips generations, it must be recessive. Individuals who are heterozygous for a recessive mutation are often referred to as carriers, because they do not manifest the condition but can pass it on to their children, depending on their mate's genotype. X-linked mutations are usually recessive for the purposes of the MCAT, and X-linked recessive conditions affect males more often. This is because females inherit one X chromosome from their mother and one from their father, while males only get their single X chromosome from their mother. Since males only have one X chromosome, having a single mutated allele will suffice to manifest a recessive mutation.
NMR area under the peaks
In 1H NMR, each hydrogen atom (or set of equivalent hydrogen atoms) produces a single peak on the spectrum. Equivalent hydrogen atoms are protons that exist in the same magnetic environment. Such protons do not differ in any measurable way, so they correspond to only one peak on the spectrum; however, if a peak corresponds to multiple equivalent hydrogen atoms, the area under that peak will be proportionally greater than the area under a peak that corresponds to a single hydrogen atom
Distillation details Next step
If all are liquids, one may be able to utilize distillation, which aims to separate liquids by utilizing the difference between their boiling points. The liquids are initially held in the same round-bottom flask, termed the distilling flask. This flask is positioned above a heat source, typically a Bunsen burner. The top of the flask is connected to a column, which leads to a downward-sloping glass condenser over a receiving flask. The condenser is held within a glass casing through which cold water is pumped. As the round-bottom flask is heated, the liquid with the lower boiling point will begin to vaporize, and its vapor will travel up the column and re-condense to fall into the receiving flask. The eventual result is a receiving flask that is rich in the lower-BP liquid, while the distilling flask will still contain the liquid(s) with the higher BP. If boiling points are very high, a vacuum may also be used to lower atmospheric pressure, which lowers the boiling points of all substances involved.
Enantiomers are molecules that _____.
If all of the chiral centers have different configurations, the isomers are non-superimposable mirror images (similar to your hands), known as enantiomers. Enantiomers have identical chemical and physical properties, but they differ in their rotation of plane-polarized light (opposite directions) as well as the products they yield when reacted with another chiral reagent. If the isomers have multiple chiral centers but differ only at some, they are known as diastereomers. Since diastereomers have very similar chemical, but less similar physical properties,
When should vacuum distillation be used?
If boiling points are very high, a vacuum may also be used to lower atmospheric pressure, which lowers the boiling points of all substances involved.
High glucose and ketone bodies
If cells cannot take up glucose, it will remain in the blood and eventually be excreted in the urine when it builds up to the point that it cannot be reabsorbed by the nephron. In a state of extended hyperglycemia, the body relies on fat metabolism to generate energy, which produces ketone bodies that are also excreted in the urine.
Entropy effect in protein structure
If hydrophilic—that is, polar—residues are facing the aqueous solution, then water will be able to hydrogen-bond freely with those residues, meaning that it will have relatively high entropy, which is energetically favorable. In contrast, water molecules will not be able to hydrogen-bond effectively with nonpolar residues, and as a result will form a highly-ordered solvation shell to minimize interactions with those residues. This highly-ordered shell represents a decrease in entropy, which is energetically unfavorable.
K channels blocks effect
If potassium ion channels are blocked, the membrane would fail to repolarize, extending the length of the action potential and simulating excessive muscle contractions.
Deactivated vs activated meaning in AP?
If the "inactivation gate" is closed, the channels are inactivated. If the inactivation gate is open but the activation gate is closed, the channel is "de-inactivated" — it isn't inactivated, but it is not yet open either. This "de-inactivation" occurs once the action potential nears its end and the membrane voltage becomes sufficiently low (generally during the hyperpolarization phase). At this time, the inactivation gate opens and the activation gate closes. Since the channel is not inactivated, a stimulus could theoretically produce an action potential, but since the cell is hyperpolarized, this stimulus would need to be larger than normal. This interval is termed the relative refractory period, which is what this question asks about. At this time, again, sodium channels are de-inactivated; potassium channels are still activated, allowing potassium to continue flowing out of the cell to finish the action potential.
Na+ and K+ roles in AP
If the excitatory stimulus is strong enough, and the cell's resting potential is brought up to −55 mV, the cell will undergo an action potential. In the first phase of the action potential, depolarization, the sodium voltage-gated channels open and Na+ ions rush into the cell. The sudden influx of positive charges continues until the cell membrane reaches full depolarization at +40 mV, at which point the sodium channels close and potassium voltage-gated channels open. Now that the interior of the cell is positive, the potassium is pushed by both electrical potential and its own concentration gradient to rush out, causing repolarization. Repolarization continues until the cell overshoots the −70 mV level, making the cell temporarily hyperpolarized, during what is called the refractory period. Then, the sodium-potassium pumps get back to work to re-establish the resting state of the cell.
IgA antibody function
IgA antibodies are present in mucosal areas such as the gut, respiratory tract, saliva, and urogenital tract.
Example of Michaelis menton concept?
Imagine a test tube with 100 molecules of enzyme X, which catalyzes the reaction S → P (with S standing for "substrate" and P for "product"), and that all other conditions are appropriate for the reaction to occur (i.e., ideal temperature and pH). If we add 10 molecules of S, we can expect that they will all be converted to P quickly, because excess X is present. If we add 50 molecules of S, the reaction will go even faster, since we still have excess X, but not 5 times as fast, since we can expect some degree of delay to occur in terms of all the molecules of S finding their way to available molecules of X. If we keep adding S, up to a certain point, the reaction rate will continue to increase, but not forever, as we only have 100 molecules of X. If all the molecules of X are occupied, we say that X is saturated.
Immunoassays
Immunoassays operate on the principle that antibodies cultured from antibody-producing cells can bind with great specificity to a protein antigen of interest. A protein in a mixture can be detected using a radioimmunoassay (RIA); in an RIA, the protein concentration can be assessed indirectly by measuring the extent to which the protein competes with a radioactively labeled standard for antibody binding sites.
RIA
Immunoassays operate on the principle that antibodies cultured from antibody-producing cells can bind with great specificity to a protein antigen of interest. A protein in a mixture can be detected using a radioimmunoassay (RIA); in an RIA, the protein concentration can be assessed indirectly by measuring the extent to which the protein competes with a radioactively labeled standard for antibody binding sites.
In Cross's Nigrescence Model
In Cross's Nigrescence Model, African-Americans are described as progressing through several stages of cultural awareness.
Sherif's Robber's Cave Experiment
In Sherif's Robber's Cave Experiment, children were grouped into different camps and, through manipulation, were encouraged to have negative attitudes towards each other. However, after given a task in which they had to collaborate, they began to view each other more favorably. It examined the intergroup conflicts that arise in response to competition over limited resources.
In X-linked recessive
In X-linked recessive mutations, many more males manifest the phenotype because males only have one X chromosome. Therefore, if males inherit a single mutated X chromosome, they will show the effects of the mutation, whereas females who inherit a single mutated X chromosome will not show the effects of the mutation due to the presence of a second, non-mutated X chromosome.
Genetic bottleneck
In a genetic bottleneck, some event (e.g. earthquake, fire, drought, war) leads to a relatively small subset of genes from the larger gene pool being passed to the next generation. Because fewer genes remain in the next generation to be passed on, overall genetic diversity in the population is reduced.
Spin-spin coupling (splitting)
In a phenomenon known as splitting, each signal is affected by protons on atoms adjacent to the carbon to which the proton is attached. Splitting patterns are predicted the n + 1 rule, which states that any peak will be split into a number of smaller peaks equal to the number of adjacent hydrogen atoms plus one. For example, if a hydrogen atom is positioned on a terminal carbon adjacent to a carbon bound to one additional hydrogen atom, the peak that represents the first hydrogen atom will be split into a doublet (1 adjacent hydrogen atom + 1 = 2).
Types of decay
In beta-minus decay, a neutron is converted into a proton in the nucleus, and a β− particle (an electron) is ejected to maintain charge balance. In beta-plus decay, a proton is converted into a neutron, and a β+ particle (a positron) is emitted to preserve charge. Gamma decay involves the emission of a gamma ray, which is a high-energy photon, from an excited nucleus. Finally, in electron capture, a nucleus "grabs" an electron, which changes a proton into a neutron.
D/L and R/S system for amino acids?
In chiral amino acids, the configuration of substituents around the α-carbon can be described in multiple ways. Under the R/S system, which is typically most familiar, all chiral amino acids are S except cysteine, which is R. Alternatively, amino acids (as well as sugars) can be classified using the D/L system, which classifies molecules based on their resemblance to glyceraldehyde. The MCAT is unlikely to ask you to determine whether an amino acid is D or L based on its drawn structure alone. However, it is important to know that only L amino acids are used by eukaryotic cells. (You can remember "L" for "living" eukaryotic cells.) However, prokaryotic - or bacterial - cells do use select D amino acids for incorporation into their cell walls.
Krebs Cycle energy production
Krebs cycle produces both ATP and NADH but not NAD+. ATP directly supplies energy for many cellular processes, such as muscle contraction, and NADH, which is used in the electron transport chain.
Classical Conditioning (Pavlov)
In classical conditioning, an unconditioned stimulus and the subsequent unconditioned response to it are used to turn a neutral stimulus into a conditioned stimulus, which causes a conditioned response. The best-known example is Pavlov's experiment on dogs. Pavlov's unconditioned stimulus was meat and the dogs' unconditioned, or instinctual, response to it was to salivate. Pavlov then introduced a neutral stimulus, which initially caused no response from the dogs. However, when he began ringing the bell before feeding meat to the dogs, the dogs began to associate the ringing of the bell with receiving meat. Eventually, the ringing of the bell alone actually made the dogs salivate. The neutral stimulus (the ringing of the bell), through association with the unconditioned stimulus (the meat), had become a conditioned stimulus that caused a conditioned response (salivating).
What is Wernicke's area ?
In contrast, Wernicke's area is located in the back of the temporal lobe, just posterior to the Sylvian fissure (the part of the brain where the temporal and parietal lobes meet). This brain area controls the comprehension of speech and written language. When Wernicke's area is damaged, the resulting condition - termed Wernicke's aphasia - causes the loss of speech comprehension. Patients with this disease can still speak and often do so at great length, but their words are nonsensical. In other words, their problems are with creating meaningful, intelligible speech, not with producing the sounds that make up words. Both Broca's and Wernicke's aphasia can result from brain injury, such as stroke.
How does mitosis differ from Meiosis?
In contrast, meiosis is a form of cell division that is essential for sexual reproduction. It takes place in germ cells (also known as sex cells). Meiosis differs from mitosis in that it has two stages and results in the formation of four daughter cells, each of which has only one copy of each chromosome (haploid, n), in contrast to mitosis, which generates cells with two copies of each chromosome (diploid, 2n) that are essentially identical to their parent cell.
In eukaryotes, DNA organization
In eukaryotes, DNA is organized into linear chromosomes, which each contain a specific part of the genome. (In contrast, prokaryotes have a smaller genome that is stored in circular DNA.) Each chromosome contains a centromere that separates the chromosome into two arms, generally known as the p-arms and the q-arms. These arms are used as part of the information needed to specify the location of a gene on a chromosome.
Process of mitosis?
In eukaryotes, the process of asexual cell division is known as mitosis. Mitosis takes place in four phases: prophase, metaphase, anaphase, and telophase. Prophase prepares the cell for mitosis: the DNA condenses such that distinct chromosomes become visible, as sister chromatids (or copies of a given chromosome) join at a region known as the centromere. The kinetochore assembles on the centromere, and is the site where microtubule fibers that extend from the centrosome and form the mitotic spindle attach to pull the sister chromatids apart in later stages of mitosis. Other microtubules known as asters extend from the centrosome to anchor it to the cell membrane. Additionally, the nuclear envelope and the nucleolus disappear, and the mitotic spindle forms. In metaphase, the chromosomes line up at the middle of the cell along an imaginary line that is known as the metaphase plate. In anaphase, the sister chromatids are separated and pulled to opposite sides of the cell by shortening of the microtubules attached to the kinetochores. Telophase can be thought of as the opposite of prophase, as a new nuclear envelope appears around each set of chromosomes and a nucleolus reappears within each of those nuclei. The process of mitosis is completed by cytokinesis.
Experimental Design
In experimental design, it is important to account for confounding variables, which are external variables affecting both the independent and dependent variable. For instance, if a study analyzes the effects of stereotype bias on math performance by race, but fails to account for socioeconomic status (SES), its results may be suspect, because SES may predict math performance and be correlated with race. Moderating variables attenuate or strengthen a given relationship, and mediating variables provide an important logical link between an independent variable and a dependent variable, or outcome.
Glomerulus malfunctioning
In healthy individuals, the structure of the glomerular capillaries prevents the entry of large molecules, such as proteins, into the filtrate.
Glycogen structure
In humans, glycogen is stored in liver and muscle cells. Structurally, glycogen is similar to amylopectin in that it contains chains of glucose molecules connected by α(1→4) glycosidic bonds, with intervening α(1→6) glycosidic bonds that create branches; the main difference is that glycogen is more heavily branched than amylopectin, with branches occurring every 8−12 units. In contrast, a polysaccharide known as cellulose plays a major structural role in the cell walls of plants. Like starch and glycogen, it is a polymer of glucose, but unlike them, it incorporates the β-anomer of glucose, with glucose subunits connected by β(1→4) glycosidic bonds.
Synapsis
In prophase I of meiosis, homologous chromosomes (i.e., the maternal and paternal copies of a given chromosome) pair up with each other in a process known as synapsis, forming tetrads. While paired up, homologous chromosomes may exchange genetic information in a process known as crossing over. The crossing-over points are known as chiasmata. This process results in recombinant DNA that is another source of variation in sexual reproduction, in addition to the variability inherent to the process.
Glycogen and cellulose structure
In humans, glycogen is stored in liver and muscle cells. Structurally, glycogen is similar to amylopectin in that it contains chains of glucose molecules connected by α(1→4) glycosidic bonds, with intervening α(1→6) glycosidic bonds that create branches; the main difference is that glycogen is more heavily branched than amylopectin, with branches occurring every 8−12 units. In contrast, a polysaccharide known as cellulose plays a major structural role in the cell walls of plants. Like starch and glycogen, it is a polymer of glucose, but unlike them, it incorporates the β-anomer of glucose, with glucose subunits connected by β(1→4) glycosidic bonds. This seemingly small structural distinction makes a world of practical difference, as humans lack the necessary enzymes to digest cellulose.
Sigmoidal shape
In humans, hemoglobin typically consists of four globular protein subunits, attached together to form the quaternary structure of the overall molecule. Each subunit contains one heme group, which is a structure consisting of a specific ring, termed a porphyrin ring. Each heme group contains one iron cation, which binds oxygen in the Fe2+ state. Since each hemoglobin molecule therefore includes four iron cations, each hemoglobin can carry up to four oxygen atoms. Binding of oxygen to any of the four binding sites causes an increase in the oxygen affinity of the remaining sites, a phenomenon known as cooperativity. Cooperative binding can be recognized by its signature sigmoidal, or S-shaped, shape; the steep part of the S denotes the sharply increased binding affinity that occurs as a result of the initial binding.
What is Broca's area?
In humans, language production and comprehension are largely controlled by two brain areas: Broca's area and Wernicke's area. Broca's area, located in the left hemisphere of the frontal lobe, controls the physical production of speech. Damage to Broca's area, termed Broca's aphasia, weakens the ability to speak. Individuals with Broca's aphasia typically have significant trouble producing words, although their comprehension (or understanding) is relatively undamaged, and they may be able to read or listen to others speak fairly normally.
Pyruvate final e acceptor
In humans, when insufficient oxygen is available (as in muscles during extended exercise), or when the necessary cellular equipment is lacking (as in red blood cells), glucose undergoes anaerobic fermentation with pyruvate acting as the final electron acceptor.
Mixed inhibition
In mixed competition, enzyme binding is a "mix" of competitive inhibition (inhibitor can only bind if substrate is unbound) and uncompetitive inhibition (inhibitor can only bind of substrate has already bound). The inhibitor will be able to bind to the enzyme whether or not the substrate has been bound, but will have differing affinities for the two different states.
Solubility, pressure, temperature
In most cases, the solubility of ionic substances in water increases with temperature, while the opposite pattern is observed for gases. This is because higher temperatures provide gases with more kinetic energy that they can use to escape the solution. Additionally, pressure favors the solubility of gases.
Polymerase Chain Reaction (PCR)
In order to design an effective PCR strategy, two pieces of information are required. First, one must know the length of the gene to be amplified so that the correct elongation time can be determined. Second, one must know the nucleotide sequence of the primer region in order to design forward and reverse primers. These primers must be complementary to the 3' ends of both strands for the region being targeted. The first step of PCR is to melt the DNA, creating two single strands. The DNA is then cooled and these primers anneal to their intended complementary nucleotide sequence. This allows DNA polymerase to copy only those segments. The polymerase will not copy other segments because it requires a primer
How enzymes inhibit substrate?
In order to properly maintain homeostasis, the activity of most enzymes is under strict control. Enzymes are regulated at many levels, from transcriptional regulation to inhibitor molecules that reduce an enzyme's ability to bind to its substrate and generate the desired product. Each inhibitor type on the MCAT differs in which step it directly affects the pathway, from the enzyme to the enzyme-substrate complex to the product + enzyme.
Electrophiles and Nucleophiles
In organic chemistry, reactions happen when a bond is formed between an electrophile and a nucleophile. Electrophiles are species that 'want' more electrons. Often, electrophiles are positively charged or partially positively charged. In contrast, nucleophiles are species that have an excess of electrons, and therefore 'want' to use those electrons to form a bond with an electrophile. This is known as nucleophilic attack.
PEP to Pyruvate steps?
In particular, the final stage of glycolysis (phosphoenolpyruvate [PEP] → pyruvate) must be bypassed by gluconeogenesis. Thus, why gluconeogenesis has a two-step pathway split up between the mitochondria and cytosol, in which pyruvate carboxylase converts pyruvate to oxaloacetate in the mitochondria by adding a COO− group. Oxaloacetate is briefly converted to malate for transport out of the mitochondria, where it is then converted immediately back to oxaloacetate. At this point, in the cytosol, PEP carboxykinase converts oxaloacetate to PEP.
Primary and secondary transport
In primary active transport, energy is used directly to move a solute against its gradient through a transmembrane channel. Secondary active transport is a more complicated system in which the energy stored in an electrochemical gradient established via primary active transport is used to facilitate the movement of a solute. An example is the sodium-calcium exchanger, which allows three Na+ ions to flow down their concentration gradient, which was previously established by a primary active transport mechanism, into the cell, while transporting one Ca2+ ion out.
Prophase I of meiosis
In prophase I of meiosis, homologous chromosomes (i.e., the maternal and paternal copies of a given chromosome) pair up with each other in a process known as synapsis, forming tetrads. While paired up, homologous chromosomes may exchange genetic information in a process known as crossing over. The crossing-over points are known as chiasmata. This process results in recombinant DNA that is another source of variation in sexual reproduction,
Cultural capital def
Knowledge, skills, education, and similar characteristics that are used to make social distinctions and are associated with differences in social status.
Details of Meiosis?
In prophase I of meiosis, homologous chromosomes (i.e., the maternal and paternal copies of a given chromosome) pair up with each other in a process known as synapsis, forming tetrads. While paired up, homologous chromosomes may exchange genetic information in a process known as crossing over. The crossing-over points are known as chiasmata. This process results in recombinant DNA that is another source of variation in sexual reproduction, in addition to the variability inherent to the process. In metaphase I, homologous pairs, which take the form of tetrads, line up at the metaphase plate. The orientation of the homologous pairs is random in terms of which side of the metaphase plate the maternal or paternal copy of a given chromosome in a homologous pair winds up. In anaphase I, the homologous pairs are separated, and one member of each pair is pulled to each side of the cell. In meiosis II, which operates similarly to mitosis, the sister chromatids are split up into two haploid daughter cells.
Phases of meiosis
In prophase I of meiosis, homologous chromosomes (i.e., the maternal and paternal copies of a given chromosome) pair up with each other in a process known as synapsis, forming tetrads. While paired up, homologous chromosomes may exchange genetic information in a process known as crossing over. The crossing-over points are known as chiasmata. This process results in recombinant DNA that is another source of variation in sexual reproduction, in addition to the variability inherent to the process. In metaphase I, homologous pairs, which take the form of tetrads, line up at the metaphase plate. The orientation of the homologous pairs is random in terms of which side of the metaphase plate the maternal or paternal copy of a given chromosome in a homologous pair winds up. In anaphase I, the homologous pairs are separated, and one member of each pair is pulled to each side of the cell. In meiosis II, which operates similarly to mitosis, the sister chromatids are split up into two haploid daughter cells.
Splicing definition
In splicing, noncoding sequences (introns) are removed and coding sequences (exons) are ligated together. (Remember that exons are expressed). Each gene normally has multiple distinct exons that can be ligated in different combinations; that is, if a gene had a set of four exons named A, B, C, and D, possible alternate splicing combinations could include ABCD, ABC, ACD, ABD, BCD, and so on. This dramatically increases the amount of different, but related proteins that can be expressed from a single gene. Splicing explains why there are over 200,000 proteins in the human body, but only approximately 20,000 genes. Splicing is carried out by the spliceosome, a combination of small nuclear RNAs (snRNAs) and protein complexes.
Splicing info
In splicing, noncoding sequences (introns) are removed and coding sequences (exons) are ligated together. (Remember that exons are expressed). Each gene normally has multiple distinct exons that can be ligated in different combinations; that is, if a gene had a set of four exons named A, B, C, and D, possible alternate splicing combinations could include ABCD, ABC, ACD, ABD, BCD, and so on. This dramatically increases the amount of different, but related proteins that can be expressed from a single gene. Splicing explains why there are over 200,000 proteins in the human body, but only approximately 20,000 genes. Splicing is carried out by the spliceosome, a combination of small nuclear RNAs (snRNAs) and protein complexes.
Splicing process for gene
In splicing, noncoding sequences (introns) are removed and coding sequences (exons) are ligated together. (Remember that exons are expressed). Each gene normally has multiple distinct exons that can be ligated in different combinations; that is, if a gene had a set of four exons named A, B, C, and D, possible alternate splicing combinations could include ABCD, ABC, ACD, ABD, BCD, and so on. This dramatically increases the amount of different, but related proteins that can be expressed from a single gene. Splicing explains why there are over 200,000 proteins in the human body, but only approximately 20,000 genes. Splicing is carried out by the spliceosome, a combination of small nuclear RNAs (snRNAs) and protein complexes.
How ATP synthase creates ATP?
In the ETC, the energy released from the series of electron transfers is used to pump H+ across the membrane. The unequal concentrations of H+ ions across the membrane establishes an electrochemical gradient, leading to chemiosmosis, or the passive diffusion of the protons down their concentration gradient, which is coupled to ATP synthase. This proton movement generates 90% of the ATP synthesized during oxidative phosphorylation.
Chemiosmotic coupling
In the ETC, the energy released from the series of electron transfers is used to pump H+ across the membrane. The unequal concentrations of H+ ions across the membrane establishes an electrochemical gradient, leading to chemiosmosis, or the passive diffusion of the protons down their concentration gradient, which is coupled to ATP synthase. This proton movement generates 90% of the ATP synthesized during oxidative phosphorylation. The electrons passing through the electron transport chain gradually lose energy until eventually they are donated to O2, which accepts two H+ ions and is transformed into water.
ETC and ATP synthase
In the ETC, the energy released from the series of electron transfers is used to pump H+ across the membrane. The unequal concentrations of H+ ions across the membrane establishes an electrochemical gradient, leading to chemiosmosis, or the passive diffusion of the protons down their concentration gradient, which is coupled to ATP synthase. This proton movement generates 90% of the ATP synthesized during oxidative phosphorylation. The electrons passing through the electron transport chain gradually lose energy until eventually they are donated to O2, which accepts two H+ ions and is transformed into water.
ETC and energy release
In the ETC, the energy released from the series of electron transfers is used to pump H+ across the membrane. The unequal concentrations of H+ ions across the membrane establishes an electrochemical gradient, leading to chemiosmosis, or the passive diffusion of the protons down their concentration gradient, which is coupled to ATP synthase. This proton movement generates 90% of the ATP synthesized during oxidative phosphorylation. The electrons passing through the electron transport chain gradually lose energy until eventually they are donated to O2, which accepts two H+ ions and is transformed into water. If the proton gradient is disrupted or destroyed, chemiosmosis can become uncoupled from the ETC, resulting in little to no ATP generation despite the transfer of electrons carrying on. Many poisons and toxins act by uncoupling the proton gradient from ATP synthase.
Ksp and Molar Solubility
Ksp is similar to, but distinct from, molar solubility, which refers to the moles of a substance that will dissolve in a solvent, because Ksp takes into account the relevant ions from any source.
How ATP synthase produces ATP
In the ETC, the energy released from the series of electron transfers is used to pump H+ across the membrane. The unequal concentrations of H+ ions across the membrane establishes an electrochemical gradient, leading to chemiosmosis, or the passive diffusion of the protons down their concentration gradient, which is coupled to ATP synthase. This proton movement generates 90% of the ATP synthesized during oxidative phosphorylation. The electrons passing through the electron transport chain gradually lose energy until eventually they are donated to O2, which accepts two H+ ions and is transformed into water. If the proton gradient is disrupted or destroyed, chemiosmosis can become uncoupled from the ETC, resulting in little to no ATP generation despite the transfer of electrons carrying on. Many poisons and toxins act by uncoupling the proton gradient from ATP synthase.
Electron Transport chain
In the electron transport chain, electrons are passed from species with less positive reduction potential to those with more positive reduction potential. O2 serves as the final electron acceptor of the electron transport chain and must possess a standard reduction potential that is more positive than any other acceptor in the chain. Of the standard reduction potentials mentioned in the passage, the greatest is that of Fe3+/Fe2+ in cytochrome c, for which E° = +0.22 V.
Induced fit model
In the induced fit model, the enzyme and substrate are seen as affecting each other; the initial stages of binding induce conformational shifts that allow closer attachment and more efficient catalysis.
Gender Identity Formation
In the realm of gender identity formation, identification refers to children's perception of themselves as subject to the same roles or norms as a parent or other model. The quality or nature of the relationship between the child and potential gender model is one of the factors that influences the strength of the child's identification with that individual
Enthalpy and entropy
In thermodynamics, a key distinction is made between enthalpy (heat energy in a system) and entropy (energy in a closed system that is unavailable to do work). The enthalpy (H) of a reaction is the heat energy it contains. The most important law when looking at enthalpy is Hess's law: ΔHrxn = Σ∆Hproducts - ΣΔHreactants. This equation illustrates that enthalpy, like entropy, is a state function. This means that the ∆H accompanying a chemical reaction is independent of the mechanism by which the reaction occurs. That is, when reactants are converted into products, the overall enthalpy change is the same whether it is done as one step or multiple steps.
Incidence and prevalence
Incidence describes the number of new cases of a disease (in this case, multiple sclerosis) during a specific time interval (a year). Prevalence rates describe how common multiple sclerosis is. More specifically, they tell us how many people (new cases and current cases) have multiple sclerosis within a certain amount of time.
Stimulant drugs
Increase both epinephrine and glutamate
Acid stregnth
Increased by the inducting effects of the electronegative atoms
Independent and Dependent Stressors
Independent stressor is assumed to occur independently of any influence from the person experiencing the stress. This is a unidirectional relationship (stressor leads to depressive symptoms). Dependent stressors, on the other hand, not only influence depression but could themselves be influenced by depression (i.e., a reciprocal relationship).
Insulin
Insulin is a peptide hormone released by the beta cells of the pancreas in response to high blood glucose levels. Its basic function is to reduce blood glucose levels by promoting the transport of glucose into cells via insulin receptors, which activate membrane-bound glucose transporters. The glucose transported into the cell can be used immediately through glycolysis; alternatively, muscle and liver cells can store the glucose as glycogen, and adipocytes (fat cells) can mobilize fatty acids to store downstream byproducts of glucose metabolism in the form of triglycerides. Insulin upregulates all those processes, as well as protein synthesis.
Insulin how works
Insulin is a peptide hormone released by the beta cells of the pancreas in response to high blood glucose levels. Its basic function is to reduce blood glucose levels by promoting the transport of glucose into cells via insulin receptors, which activate membrane-bound glucose transporters. The glucose transported into the cell can be used immediately through glycolysis; alternatively, muscle and liver cells can store the glucose as glycogen, and adipocytes (fat cells) can mobilize fatty acids to store downstream byproducts of glucose metabolism in the form of triglycerides. Insulin upregulates all those processes, as well as protein synthesis.
Intellectual capital
Intellectual capital is the knowledge set an individual possesses. The goal of education in society is, ostensibly, to transfer intellectual capital to the next generation. Many forms of upward social mobility are based upon the value of intellectual capital. For example, attending college is an exchange of financial capital for intellectual (or cultural) capital.
Intellectual capital and spiritual capital
Intellectual capital is the knowledge set an individual possesses. The goal of education in society is, ostensibly, to transfer intellectual capital to the next generation. Many forms of upward social mobility are based upon the value of intellectual capital. For example, attending college is an exchange of financial capital for intellectual (or cultural) capital. Spiritual capital reflects the feelings, attitudes, and fulfilling beliefs that an individual holds while practicing their formal religion or any form of personal spirituality he or she uses as a way to connect with the world around them. Spiritual capital is similar to intellectual capital, but is deeper, more personal, and less quantifiable.
Intellectualization
Intellectualization is the use of cognitive processes to separate oneself from the real problem and avoid emotions and impulses that may arise.
Intensity
Intensity is inversely proportional to area It is the power over the unit area
Intergenerational mobility
Intergenerational mobility refers to social mobility between generations, typically between parents and children. For example, the baseball pitcher described earlier in this explanation displayed intergenerational mobility. This can be contrasted with intragenerational mobility, which refers to degrees of social mobility of members of the same generation, such as brothers.
Intra vs intermolecular bonds?
Intermolecular forces are attractive forces between molecules that are notably weaker than intramolecular bonds. For this reason, it is typically fairly easy to disrupt these attractions using common lab techniques, such as heating. There are three main categories of intermolecular forces to know for the MCAT: hydrogen bonding, dipole-dipole interactions, and van der Waals forces
Intermolecular forces
Intermolecular forces are attractive forces between molecules that are notably weaker than intramolecular bonds. For this reason, it is typically fairly easy to disrupt these attractions using common lab techniques, such as heating. There are three main categories of intermolecular forces to know for the MCAT: hydrogen bonding, dipole-dipole interactions, and van der Waals forces.
Internal validity def
Internal validity denotes how well an experiment is executed, especially whether it avoids confounding variables (more than one possible independent variable acting at the same time). The less chance for confounding in a study, the higher its internal validity.
Internal validity
Internal validity determines if a study is actually measuring what it intends to measure. Confounding variables, temporality, and bias are all important aspects of internal validity
Internalization
Internalization occurs when an individual genuinely agrees with the values/behaviors/attitudes that he or she is conforming with and finds the behavior to be inherently rewarding. The related behavior of compliance occurs when an individual yields to social pressure (typically in response to a direct request) because he or she wishes to get a positive reaction from another individual or group, or to avoid social disapproval by others.
Endosomes
Internalization of viral particles through endocytosis is mediated by endosomes.
Interphase and its parts
Interphase is when a cell prepares for division, and it can take up approximately 90% of the time of the cell cycle. Two major things happen during interphase: growth and DNA replication. However, interphase is broken into three stages: Gap 1 (G1), synthesis (S), and Gap 2 (G2). During G1 and G2, the cell grows, and during S, DNA is replicated. The fact that S is located between G1 and G2 allows checkpoints. The G1/S checkpoint, also known as the restriction point, is when a cell commits to division. The presence of DNA damage or other external factors can cause a cell to fail this checkpoint and not divide. The G2 checkpoint that takes place before cell division similarly checks for DNA damage after DNA replication, and if damage is detected, serves to "pause" cell division until the damage is repaired. Throughout interphase, chromatin is loosely packaged (euchromatin) to allow transcription and replication.
Interphase info
Interphase is when a cell prepares for division, and it can take up approximately 90% of the time of the cell cycle. Two major things happen during interphase: growth and DNA replication. However, interphase is broken into three stages: Gap 1 (G1), synthesis (S), and Gap 2 (G2). During G1 and G2, the cell grows, and during S, DNA is replicated. The fact that S is located between G1 and G2 allows checkpoints. The G1/S checkpoint, also known as the restriction point, is when a cell commits to division. The presence of DNA damage or other external factors can cause a cell to fail this checkpoint and not divide. The G2 checkpoint that takes place before cell division similarly checks for DNA damage after DNA replication, and if damage is detected, serves to "pause" cell division until the damage is repaired. Throughout interphase, chromatin is loosely packaged (euchromatin) to allow transcription and replication.
Intersectionality
Intersectionality calls attention to how identity categories intersect in systems of social stratification. For example, an individual's position within a social hierarchy is determined not only by his or her social class, but also by his or her race/ethnicity. Intersectionality can also refer to intersections involving other identity categories such as age, gender, or sexual orientation.
Intersectionality basics
Intersectionality is the idea that people can be oppressed due to several characteristics (race, ethnicity, gender, social orientation, etc.) at once, and these characteristics intersect in ways that can impact their experiences and social treatment.
Eysenck's Trait Theory
Introversion-solitary and reserved Extroversion-outgoing and sociable Stable-calm and relaxed Instable-moody and anxious
Irving Goffman
Irving Goffman's theory of self would be the most directly applicable. This theory suggests that individuals have an inner and outer self that regulates behavioral choices such as justifying the donation of various fluids and body parts based on societal morals and ethics.
Isoelectric focusing
Isoelectric focusing requires the use of a gel that has a stable pH gradient. A protein that is in a region of the gel where the pH is below its pI will be positively charged and will migrate towards the negatively-charged plate (the cathode). The protein will cease to migrate when it reaches the region of the gel where the pH of the gel equals the pI of the protein. At this point, the protein will stop migrating because the net charge of the protein will be 0, so it will not experience any electric force.
Korsakoff syndrome
Korsakoff syndrome is a chronic memory disorder caused by severe deficiency of vitamin B1 (thiamine). Korsakoff syndrome most commonly occurs due to alcohol abuse. Thiamine deficiency leads to a reduction in the activity of certain enzymes, which causes a reduction in mitochondrial activity, decreased energy production, and eventually selective neuronal death.
Isoelectric focusing (IEF)
Isoelectric focusing requires the use of a gel that has a stable pH gradient. A protein that is in a region of the gel where the pH is below its pI will be positively charged and will migrate towards the negatively-charged plate (the cathode). The protein will cease to migrate when it reaches the region of the gel where the pH of the gel equals the pI of the protein. At this point, the protein will stop migrating because the net charge of the protein will be 0, so it will not experience any electric force. The proteins analyzed using isoelectric focusing will be separated based on the relative number of acidic and basic residues that they contain.
Isoelectric focusing basics
Isoelectric focusing requires the use of a gel that has a stable pH gradient. A protein that is in a region of the gel where the pH is below its pI will be positively charged and will migrate towards the negatively-charged plate (the cathode). The protein will cease to migrate when it reaches the region of the gel where the pH of the gel equals the pI of the protein. At this point, the protein will stop migrating because the net charge of the protein will be 0, so it will not experience any electric force. The proteins analyzed using isoelectric focusing will be separated based on the relative number of acidic and basic residues that they contain.
Solvation and protein with entropy
It has to do with entropy, think of putting oil in water how it aggregates together, it does this to reduce the amount of surface area exposed to the water. Water likes to hydrogen bond with itself and be disordered as it is a liquid, and when something it can't bond with or solvate, gets in the way it forces the hydrogen bonding to become more ordered and thus decreases the entropy of the system, from a thermodynamic stand point that is highly unfavorable the water doesn't like to be ordered, so what happens instead is the hydrophobic amino acids will aggregate towards the center of its protein to try and reduce as much surface area exposed to the water as possible and expose the hydrophilic amino acids to the water instead, with these amino acids you should be able to tell from looking at their structures or knowing their characteristics that they are capable of hydrogen bonding which in turn will increase the entropy of the system which is favorable
Depression
It is a mood disorder
Demographic Transition Model
It is broken down into the following four stages: In Stage 1, a society is preindustrial and has high fertility and mortality rates. In Stage 2, a society sees significant enough improvements in healthcare, sanitation, nutrition, and wages that the mortality rate drops. However, the fertility rate remains high, meaning that the population rapidly expands. In Stage 3, a society sees a decrease in the fertility rate due to a move from an agricultural to an industrial economy, as well as improvements in contraception and women's rights. In Stage 3, in order for children to be productive in society, they must go to school for many years. Furthermore, they may need to be supported by their parents for longer than they formerly were, which encourages families to have fewer children. In Stage 4, a society becomes fully industrialized and both fertility and mortality rates are low. Demographics—and demographic changes—have broad effects on many aspects of society, including health care and the health of its citizens, so it is important to be able to predict how the various stages of the demographic transition are linked to other aspects of society.
polyurea
It is caused by decreasing movement of water through cells in the descending limb of Henle
Solomon Asch experiment
It is done to find out peer pressure and conformity
Prefrontal cortex
It specifically deals with processing and displaying negative emotions (Right one)
Kinetic friction
Kinetic friction (or Fkinetic) is a force that acts in opposition to objects that are already sliding. Fkinetic can be calculated using the equation Fkinetic = μkN, where μk refers to the coefficient of kinetic friction (a value that depends on the surface and object, and that will typically be given) and N refers to the normal force, or the force exerted by the surface on the object.
Kinship
Kinship can be thought of as an extension of family, but it refers less to our blood relations and more to who we consider as belonging to our family (who do you spend holidays with, etc.). For example, family friends who have been around so long that they are called "aunt" and "uncle" would be considered kin, even though they are not blood relations.
Plasma protein and osmotic pressure
Large plasma proteins, such as albumin, in the blood increase the osmotic pressure of the blood, which in turn, increases the return of fluid to the circulatory system from the body tissues. Therefore, with malnutrition, the osmotic pressure of the blood would decrease resulting in an increase of fluid in the body tissues.
Types of power?
Legitimate power refers to the ability to compel action through a sense of social or cultural authority. Referent power uses group membership as a motivational tool, and expert power is derived from expertise. More recently, theorists have distinguished informational power as distinct from expert power. Informational power refers to the ability to deploy relevant information to bring about change or influence others' behavior, while expert power refers to the power conferred by the socially symbolic status of being a credentialed expert in a field.
strong base examples
LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2, Sr(OH)2, Ba(OH)2
Visual process description
Light enters the eye through the clear portion at the front of it, the cornea. Because the cornea is highly curved, light is refracted as it passes through it. The cornea also protects the eye. Light then passes through the pupil, which can be constricted or dilated by the autonomic nervous system to allow appropriate amounts of light in. It then moves through the lens, which can be precisely adjusted by the ciliary muscle to ensure that light is focused on the retina, which is located at the back of the eye. The retina is part of the central nervous system that contains the photoreceptors (cones and rods) that convert light into electrical impulses to be sent to the brain. Cones perceive color and fine detail, while rods allow for the perception of light and dark. Once the light is transformed into nervous system signals, the information travels along different routes depending on the direction from which the light entered the eye, as shown below.
Vision
Light enters the eye through the clear portion at the front of it, the cornea. Because the cornea is highly curved, light is refracted as it passes through it. The cornea also protects the eye. Light then passes through the pupil, which can be constricted or dilated by the autonomic nervous system to allow appropriate amounts of light in. It then moves through the lens, which can be precisely adjusted by the ciliary muscle to ensure that light is focused on the retina, which is located at the back of the eye. The retina is part of the central nervous system that contains the photoreceptors (cones and rods) that convert light into electrical impulses to be sent to the brain. Cones perceive color and fine detail, while rods allow for the perception of light and dark. Once the light is transformed into nervous system signals, the information travels along different routes depending on the direction from which the light entered the eye, as shown below. Each eye's right visual field is projected onto the left half of the eye's retina. As the electrical signals carrying visual information travel to the occipital lobe, the first major event happens at the optic chiasm, where optical fibers from the nasal half of each retina (i.e. the half of each retina closest to an individual's nose) cross paths. In contrast, the temporal fibers (i.e. the fibers from the lateral sides of the eyes) do not cross paths. This means that once optic fibers get through the optic chiasm, the fibers corresponding to the left visual field from both eyes are projected onto the right side of the brain, and vice versa. Once they have passed through the optic chiasm, the signals goes on to eventually reach the visual processing region of the brain, the occipital lobe.
Visual process
Light enters the eye through the clear portion at the front of it, the cornea. Because the cornea is highly curved, light is refracted as it passes through it. The cornea also protects the eye. Light then passes through the pupil, which can be constricted or dilated by the autonomic nervous system to allow appropriate amounts of light in. It then moves through the lens, which can be precisely adjusted by the ciliary muscle to ensure that light is focused on the retina, which is located at the back of the eye. The retina is part of the central nervous system that contains the photoreceptors (cones and rods) that convert light into electrical impulses to be sent to the brain. Cones perceive color and fine detail, while rods allow for the perception of light and dark. Once the light is transformed into nervous system signals, the information travels along different routes depending on the direction from which the light entered the eye....
Lyase
Lyases catalyze reactions where functional groups are added to break bonds in molecules or they can be used to form new double bonds or rings by the removal of functional group(s). Decarboxylases are examples of lyases. Isomerases catalyze reactions that transfer functional groups within a molecule so that a new isomer is formed to allow for structural or geometric changes within a molecule.
Ultraviolet and infrared
Light with a wavelength less than 400 nm is called ultraviolet. Light with a wavelength greater than 700 is called infrared.
What is Lineweaver-Burk plot?
Lineweaver-Burk plots may also be used. When the experimental data are examined in the form of double reciprocal Lineweaver-Burk plots, the x- and y-axes are 1/[S] and 1/V, respectively. Since these plots are a straight line, the slope of each line is Km/Vmax. The y-intercept on a Lineweaver-Burk plot represents 1/Vmax, while the x-intercept is −1/Km. These double-reciprocal plots are especially useful for distinguishing between competitive and noncompetitive inhibitors.
Efficiency equal to
Load* Load distance/Effort* effort distance
long-term memory (LTM)
Long-term memory is divided into implicit memory, also known as nondeclarative memory, and explicit memory, also known as declarative memory. Implicit (nondeclarative) memory accounts for acquired skills and conditioned responses to circumstances and stimuli. This also includes procedural memory, which accounts for motor skills and specific physical actions. The cerebellum plays a primary role in encoding implicit memories. Explicit (declarative) memory accounts for memories that we must consciously recall with effort and focus. A further division within explicit memory is between episodic memory, which accounts for our experiences, and semantic memory, which accounts for facts and concepts that we know. The hippocampus plays a primary role in encoding explicit memories.
LTM (Long-term memory)
Long-term memory, which is currently theorized to have a potentially infinite capacity. Long-term memory is divided into implicit memory, also known as nondeclarative memory, and explicit memory, also known as declarative memory. Implicit (nondeclarative) memory accounts for acquired skills and conditioned responses to circumstances and stimuli. This also includes procedural memory, which accounts for motor skills and specific physical actions. The cerebellum plays a primary role in encoding implicit memories. Explicit (declarative) memory accounts for memories that we must consciously recall with effort and focus. A further division within explicit memory is between episodic memory, which accounts for our experiences, and semantic memory, which accounts for facts and concepts that we know. The hippocampus plays a primary role in encoding explicit memories.
Reception Learning
Louie's experience is an example of reception learning. Reception learning refers to learning that comes from instruction. Reception learning is important because not all learning can be done by experience. Teachers, books and films can help structure learning.
Lyase info
Lyases catalyze reactions where functional groups are added to break bonds in molecules or they can be used to form new double bonds or rings by the removal of functional group(s). Decarboxylases are examples of lyases. Isomerases catalyze reactions that transfer functional groups within a molecule so that a new isomer is formed to allow for structural or geometric changes within a molecule.
MRI (magnetic resonance imaging)
MRI scans use magnetic fields and radio waves to image parts of the brain while avoiding the dangers of bombarding the body with ionizing radiation such as X-rays. Functional MRI, or fMRI, trades spatial resolution for temporal resolution and allows scientists to map active parts of the brain. It does so by analyzing the differences in oxyhemoglobin and deoxyhemoglobin concentration in parts of the brain
How MRI works??
MRI scans use magnetic fields and radio waves to image parts of the brain while avoiding the dangers of bombarding the body with ionizing radiation such as X-rays. Functional MRI, or fMRI, trades spatial resolution for temporal resolution and allows scientists to map active parts of the brain. It does so by analyzing the differences in oxyhemoglobin and deoxyhemoglobin concentration in parts of the brain.
Macrosociological study
Macrosociological studies are big-picture studies that rely on data from precincts, counties, states, or nations. The
Why saltatory conduction is imortant?
Maintaining a propagating action potential requires ions to enter and exit the axon, which cannot happen effectively in myelinated areas. For this reason, neurons contain gaps in the myelin sheath termed nodes of Ranvier. At these nodes, Na+ and K+ ions can cross the membrane when their respective voltage-gated membrane channels are open. The result is a signal that is strong and consistent, but that appears to move down the axon by jumping from one node of Ranvier to the next. This jump-like phenomenon is known as saltatory conduction.
Self-discrepancy theory
Maintains that each of us has three selves: actual, ideal, and ought self (representation of the way others think we should be)
Thermoregulation def
Maintenance of a constant internal body temperature.
Major depressive disorder
Major depressive disorder can be diagnosed once a person has at least one major depressive episode. Major depressive episodes last a minimum of 2 weeks.
surface area to volume ratio
Many biological processes depend on a very high surface area-to-volume ratio. The large number of tiny alveolar sacs in the lungs, the presence of microvilli in the small intestine, and the folding of the inner mitochondrial membrane are all examples in which an increased surface area allows for biological processes to take place more quickly. When the individual alveoli break down (as, for example, in emphysema) the lungs lose the necessary surface area to allow for effective diffusion of respiratory gases.
Coenzymes
Many coenzymes are vitamins or derivatives of vitamins, and they often contribute to the function of enzymes by carrying certain functional groups from one place to another in a reaction. Perhaps the most well-known example of this is coenzyme A, which transfers acyl groups from one place to another. Coenzymes that are tightly (or even covalently) bonded to their enzyme are known as prosthetic groups.
Coenzymes and prosthetic group
Many coenzymes are vitamins or derivatives of vitamins, and they often contribute to the function of enzymes by carrying certain functional groups from one place to another in a reaction. Perhaps the most well-known example of this is coenzyme A, which transfers acyl groups from one place to another. Coenzymes that are tightly (or even covalently) bonded to their enzyme are known as prosthetic groups. A famous example of an organometallic prosthetic group is heme, which contains an iron ion in the center of a porphyrin ring, and is attached to oxygen-transport proteins such as hemoglobin and myoglobin.
Marginalization
Marginalization occurs when immigrants are not involved in many processes in main-stream society
Somatic Disorders
Marked by somatic (bodily) symptoms that cause significant stress or impairment. Somatic Symptom Disorder Illness Anxiety Disorder Conversion Disorder
Material capital
Material capital refers to any inanimate physical objects that one can obtain within society (i.e. "things"). Resources like metal, timber, fossil fuels, buildings, bridges, and other pieces of societal infrastructure such as computers and technology are considered material capital.
Meiosis I
Meiosis I results in 2 haploid cells, each with 23 chromosomes consisting of 2 sister chromatids per chromosome. In the male, the sister chromatids are split into 4 gametes during meiosis II. For females, meiosis I results in a secondary oocyte (a gamete) and a polar body. Penetration of the secondary oocyte by a sperm brings on anaphase II. Telophase II produces a zygote and a second polar body. Remember for the MCAT: mitosis results in diploid daughter cells, while meiosis results in haploid cells to produce gametes.
Mature sperm cells
Mature sperm cells are very compact, and contain roughly the bare minimum of structures necessary for their functionality. A mature sperm cell has a head, a mid-piece, and a tail. The head contains the cell's DNA and is surrounded by the acrosomal cap. The mid-piece contains abundant mitochondria, which are necessary because sperm cells require quite a bit of energy throughout their life cycle, and the tail provides motility.
Generalized other
Mead's term for the cultural norms and values we use as references when evaluating ourselves.
Medicalization
Medicalization is what allows cultures to decide what is to be treated as a medical condition. Over time, new patterns of behavior or physical symptoms can be defined and treated as medical conditions, and thus become the subject of medical study, diagnosis, prevention, or treatment.
Medicalization
Medicalization refers to the taken-for-granted process in which a problem comes to be defined and treated by the social institution of medicine. A behavior undergoes medicalization when both the definition of the problem and the therapy intended to improve it are couched in medical terms.
Meiosis
Meiosis is a form of cell division that is essential for sexual reproduction. It takes place in germ cells (also known as sex cells). Meiosis differs from mitosis in that it has two stages and results in the formation of four daughter cells, each of which has only one copy of each chromosome (haploid, n), in contrast to mitosis, which generates cells with two copies of each chromosome (diploid, 2n) that are essentially identical to their parent cell.
recall cues
Memories are held in storage by a web of associations; these associations are like anchors that help retrieve memory • Priming • Context-dependent memory • State-dependent memory
Korsakoff's syndrome info
Memory disorders are characterized by memory loss. These disorders can be due to many different physiological conditions, so you should focus on learning the brain areas most likely involved (i.e., hippocampus, cortex, basal ganglia). Korsakoff syndrome is a chronic memory disorder caused by severe deficiency of vitamin B1 (thiamine). Korsakoff syndrome most commonly occurs due to alcohol abuse. Thiamine deficiency leads to a reduction in the activity of certain enzymes, which causes a reduction in mitochondrial activity, decreased energy production, and eventually selective neuronal death.
Memory reconstruction
Memory is reconstructive in that we can use our own experiences, expectations and other cognitive processes to fill in missing areas of our own memories.
Mesolimbic pathway
Mesolimbic pathway (or reward pathway), which is located in the midbrain and plays a role in addiction.
Micofilaments and Microtubules
Microfilaments are distinguished from the microtubules that compose the spindle apparatus by their composition. Kinesin and synein are primarily associated with microtubules, whereas motor proteins like myosin are associated with microfilaments. Cytokinesis is primarily escuted by components of the cytoskeleton called microfilaments
Microtubules
Microtubules are cellular structures that originate from centrosomes.
Microtubules
Microtubules are used in the transport of vesicles and the positioning of organelles within the cell. As part of this role, they form structures that assist in the transport of phagosomes (vesicles that contain particles that have been engulfed via phagocytosis) to the lysosomes of the cell, to which the phagosomes fuse. Microtubules also form the spindle apparatus that is an essential part of both mitosis and meiosis.
Milgram's electric shock experiment
Milgram's electric shock experiment also relates to authority. This experiment indicated that participants were willing to administer painful stimuli to others if instructed to do so by an authority figure. In reality, the "others" in the study were actors who were simply pretending to be shocked.
Mindfulness
Mindfulness is the psychological practice of turning one's attention back to what is happening in the here and now. It has long been part of meditation traditions, but it has also received increasing attention in modern Western psychology due to its possible benefits for psychological health.
Unique thing about mitochondria?
Mitochondria are also unique in that they are self-replicating organelles. They contain their own DNA (mitochondrial DNA, or mtDNA), which is circular in structure and inherited maternally, and undergo binary fission. This remarkable fact has been explained through the endosymbiotic origin hypothesis, according to which mitochondria derive from an original prokaryotic cell capable of aerobic metabolism that became engulfed in another cell, resulting in an endosymbiotic lineage.
Mitosis, Meiosis and sister chromatids
Mitosis separates sister chromatids to create two diploid daughter cells. Meiosis I separates homologous chromosomes to create haploid daughter cells, each of which divides again, separating sister chromatids in Meiosis II to create two haploid cells.
Phases of mitosis
Mitosis takes place in four phases: prophase, metaphase, anaphase, and telophase. Prophase prepares the cell for mitosis: the DNA condenses such that distinct chromosomes become visible, as sister chromatids (or copies of a given chromosome) join at a region known as the centromere. The kinetochore assembles on the centromere, and is the site where microtubule fibers that extend from the centrosome and form the mitotic spindle attach to pull the sister chromatids apart in later stages of mitosis. Other microtubules known as asters extend from the centrosome to anchor it to the cell membrane. Additionally, the nuclear envelope and the nucleolus disappear, and the mitotic spindle forms. In metaphase, the chromosomes line up at the middle of the cell along an imaginary line that is known as the metaphase plate. In anaphase, the sister chromatids are separated and pulled to opposite sides of the cell by shortening of the microtubules attached to the kinetochores. Telophase can be thought of as the opposite of prophase, as a new nuclear envelope appears around each set of chromosomes and a nucleolus reappears within each of those nuclei. The process of mitosis is completed by cytokinesis.
Moderating vs mediating variables
Moderating variables attenuate or strengthen a given relationship, and mediating variables provide an important logical link between an independent variable and a dependent variable, or outcome.
Molality
Molality (m) is a measure of concentration that represents the number of moles of solute per kilogram of solvent (mol/kg). For aqueous solutions with relatively small amounts of solute, molality and molarity values tend to be similar. This is because one liter of water weighs one kilogram, and therefore the difference between "liters of solution" and "kilograms of water" only becomes meaningful when there is enough solute present to materially affect the volume of the solution.
Oxygen as final Electron acceptor
Molecular oxygen serves as the terminal electron acceptor of the ETC. As such, its reduction potential must be greater (more positive) than that of any other molecule that participates in the chain.
Chromatography basics
Molecules that interact more strongly with the stationary phase will take longer to pass through it, whereas molecules that interact more weakly with the stationary phase will pass through it more quickly. Common factors that shape these interactions include molecular characteristics related to adsorption, polarity- or charge-based affinity for the stationary/mobile phase, and differences in molecular weight.
Degree of unstauration?
Molecules with at least one double bond (or a ring structure) are considered unsaturated, and a quantity known as the degree of unsaturation can be used to predict the structural features of an unsaturated compound by indicating how many double-bond equivalents are present in the compound. It can be defined as (2C + 2 + N - H - X)/2, where C is the number of carbons, N is the number of nitrogens, H is the number of hydrogens, and X is the number of halogens.
Secondary reinforcer
Money is a secondary reinforcer since it requires a pairing or association with a primary reinforcer for it to have value.
Moral hypocrasy
Moral hypocrisy is a situation in which a person appears to be a moral person but doesn't actually try to pursue moral behavior
Mores
Mores refer to norms in society that are related to morals. Unprofessional and unethical behavior violates standards for moral behavior. When mores are violated, people typically disapprove, but legal action is not taken.
Metal Oxides
Most are solids in STP
Tertiary structure of protein
Most inactive enzymes have modifications of the active site, which is a part of the tertiary structure
Magnetic quantum number (ml)
Next, the magnetic quantum number (ml) describes the spatial orientation of the orbital in question within its subshell. Potential values of ml range from −l to +l. Since each orbital can hold a maximum of two electrons, this means that an s subshell can contain up to two electrons, a p subshell can hold up to six electrons, a d subshell can contain up to 10, and an f subshell can hold up to 14.
Motivation,s drive, urge
Motivation refers to the driving force or reasoning behind our actions and behaviors. Motivation can be broadly divided into two types: extrinsic motivations are created by external forces, while intrinsic motivations are created by internal forces. These forces include attitudes, or ways of thinking or feeling about people, places, and things that are reflected in our actions and our behaviors. Our motivations and behaviors can be shaped by several factors. Instincts are innate, unlearned, and usually fixed patterns of behavior that are, in general, present in all members of a species. One example found in humans is the instinct to suckle: babies do not need to be taught how to suckle milk from their mothers or bottles. Additionally, arousal describes how even when all instincts are fulfilled, people are still motivated to do things, sometimes out of boredom and sometimes out of curiosity. That is, some behaviors are motivated by a desire to achieve an optimal level of arousal (the physiological state of being reactive to stimuli). If a person is not stimulated enough and is below their optimal level of arousal, their desire for arousal may motivate an action, decision, or behavior. A drive is an urge that results from an urge to reach a goal or satisfy a need. Basic drives stem from states of physiological need like hunger or thirst. In these basic cases, the drive would be to eat or drink. Such drives are known as primary drives and are ways that the body is alerted to being out of equilibrium. In contrast, secondary drives are not based on biological needs. Instead, they stem from learning and experiences. Secondary drives can include feelings such as love and aggression. Finally, needs are rooted in higher-level desires. For example, a young person may aspire to be a doctor not just for the financial reward, but out of as desire to help others.
Motor disorders details
Motor disorders can originate from anywhere along the motor pathways (cortex to spinal cord to target muscles). Therefore, when diagnosing a motor disorder, an important step is to check for physical evidence that may suggest where the blockage or loss of signal is occurring. Parkinson's disease is a motor disorder characterized by stiff, rigid movements of the limbs, along with tremors, slowed movements, and impaired balance. The disease is caused by a loss of dopamine-producing cells in the brain. Dopamine is a neurotransmitter that transmits signals within the brain, so the coordination among nerve and muscle cells is disrupted in Parkinson's. Multiple sclerosis (MS) affects the central nervous system. The consensus is that MS is an autoimmune disease caused by the immune system attacking and damaging the myelin sheath in the nervous system. The loss of myelin impairs nervous signal conduction. The exact symptoms of MS depend on which nerve fibers are damaged.
Types of selections
Multiple "types" of selection have been identified to describe the outcomes associated with different types of selective pressures on phenotypes that vary along a spectrum. Stabilizing selection occurs if both extremes are selected against, directional selection occurs if only one extreme phenotype is selected against and the other extreme is favored, and disruptive selection occurs when the median phenotype is selected against.
Opioid withdrawal
Muscles aches, restlessness, anxiety, lacrimation, runny nose, excessive sweating, inability to sleep, and excessive yawning
Fast twitch muscle fibers
Muscles that rely exclusively on glycolysis are known as fast, glycolytic fibers. Per glucose metabolized, or per ATP produced, they will produce much more lactic acid than slow, oxidative fibers that preferentially rely on aerobic respiration.
Agents of socialization
Music is an important part of popular culture, which is an agent of socialization. Besides popular culture, other agents of socialization include schools, family, and religion. Sociologists use the term agents of socialization to refer to parts of society that are important for socialization
Myelin basics
Myelin is a substance that coats the axons of some neurons. Composed largely of lipids, myelin is an effective electrical insulator. An action potential must propagate down the axon to reach the neighboring neuron or target cell, meaning that the faster the potential can propagate (i.e. the higher the nerve conduction velocity), the sooner the signal can reach its target. Myelin acts to increase this conduction velocity. As an insulator, myelin provides very high resistance around the membrane of the axon. In contrast, the interior of the axon - the inside of the cell - has much lower resistance, so the signal can propagate down the axon without "leaking" out of the neuron.
What is Myelin?
Myelin is a substance that coats the axons of some neurons. Composed largely of lipids, myelin is an effective electrical insulator. An action potential must propagate down the axon to reach the neighboring neuron or target cell, meaning that the faster the potential can propagate (i.e. the higher the nerve conduction velocity), the sooner the signal can reach its target. Myelin acts to increase this conduction velocity. As an insulator, myelin provides very high resistance around the membrane of the axon. In contrast, the interior of the axon - the inside of the cell - has much lower resistance, so the signal can propagate down the axon without "leaking" out of the neuron.
SN1 reaction info
N1 reactions, which - contrary to what you may expect - take place in two distinct steps. In the first step, the leaving group dissociates from the target substrate molecule, leaving behind an unstable carbocation. Since the product is so unstable, this step is slow and thus rate-determining. (This is where the "1" in SN1 comes from; it denotes the fact that only one molecule - the substrate - is involved in this first step.) In the second step, the nucleophile attacks the carbocation to form a more stable product molecule. Since the carbocation intermediate is planar, or lacks stereochemistry, SN1 reactions with chiral substrates produce an even mix of enantiomers termed a racemic mixture. Carbocation stability is the primary factor in SN1 reaction rate. For this reason, SN1 reactions favor tertiary substrates (as tertiary is the most stable carbocation structure) and occur to a negligible extent with primary substrates.
Glucose-6-phosphate dehydrogenase
NADPH is critical to the function of antioxidants (such as glutathione) that are important in maintaining the integrity of red blood cells. The pentose phosphate pathway is the primary source of this NADPH and glucose-6-phosphate dehydrogenase (G6PD) is the first and regulated step of this pathway. Its inhibition would lead to a decrease in NADPH levels and impair red blood cells' capacity to cope with oxidative stresses
Oxidative vs. Nonoxidative PPP
NADPH is produced only in the oxidative phase of the pentose phosphate pathway. Therefore, the answer to the second part of this question must be the oxidative phase. Remember that the oxidative phase is irreversible, while the non-oxidative phase is reversible. Ribulose 5-phosphate, a product of both the oxidative and non-oxidative pathways, can be converted to ribose 5-phosphate, which in turn can be used to make nucleotides. Therefore, both the oxidative and non-oxidative phases could be utilized for nucleotide production. In the oxidative phase, a carbon dioxide molecule is lost when converting the six-carbon glucose 6-phosphate to the five-carbon ribulose 5-phosphate. However, no carbon dioxide is lost in the non-oxidative phase. Thus, the non-oxidative phase yields more moles of ribulose 5-phosphate per mole of glucose 6-phosphate than the oxidative phase.
Na+K+ ATPase
Na+K+ ATPase transports 3 Na+ outside of the cell and 2 K+ inside of the cell per molecule of ATP hydrolyzed
Nasal and temporal halves
Nasal cross but temporal do not cross the optic chiasma
Ectoderm
Nervous system, skin, epidermis, and sensory organs
PNS neural pathways
Neural pathways in the peripheral nervous system (PNS) convey information to the central nervous system (CNS) and relay instructions. Those that take information to the CNS are known as afferent nerves, and those that relay instructions from the CNS are known as efferent nerves. As the names suggest, sensory nerves relay information about sensation, and motor nerves carry information about motions that need to be performed. Sensory and motor nerves either connect to the spinal cord, in which case they are called spinal nerves, or directly enter the skull, in which case they are cranial nerves
Neural pathways short details
Neural pathways in the peripheral nervous system (PNS) convey information to the central nervous system (CNS) and relay instructions. Those that take information to the CNS are known as afferent nerves, and those that relay instructions from the CNS are known as efferent nerves. As the names suggest, sensory nerves relay information about sensation, and motor nerves carry information about motions that need to be performed. Sensory and motor nerves either connect to the spinal cord, in which case they are called spinal nerves, or directly enter the skull, in which case they are cranial nerves.
Neurotransmitters acetylcholine
Neurotransmitters can also be active in the peripheral nervous system. Most notably, acetylcholine activates muscle contraction at the neuromuscular junction. It is used in all autonomic outputs from the brain to autonomic ganglia, and in the parasympathetic nervous system for post-ganglionic connections. Serotonin regulates intestinal movement in the gastrointestinal tract, in addition to its effects in the brain. Epinephrine stimulates the fight-or-flight response, and norepinephrine is used in post-ganglionic connections in the sympathetic division of the autonomic nervous system. It also increases arousal and alertness and focuses attention.
Non material culture
Non material culture describes the intangible thoughts or ideas that make up the overall culture of a society
Non-coding RNA
Non-coding RNA plays a role in gene expression. MicroRNA (miRNA) strands are single-nucleotide strands incorporated into an RNA structure with a characteristic hairpin loop, while small interfering RNA (siRNA) molecules are short and double-stranded. Both tend to be approximately 22 nucleotides in length, and silence genes by interrupting expression between transcription and translation.
What is Noncompetitive inhibition ?
Noncompetitive inhibition is when the inhibitor does not compete with the substrate for the active site, but reduces enzyme activity by binding to another site (the allosteric site) on the enzyme. In noncompetitive inhibition, the inhibitor can combine with either the enzyme or the enzyme-substrate complex. In pure noncompetitive inhibition, the value of Vmax is decreased. Since these inhibitors do not compete with the substrate, their activity is unaffected by substrate concentration.
Noncompetitive inhibition
Noncompetitive inhibition is when the inhibitor does not compete with the substrate for the active site, but reduces enzyme activity by binding to another site (the allosteric site) on the enzyme. In noncompetitive inhibition, the inhibitor can combine with either the enzyme or the enzyme-substrate complex. In pure noncompetitive inhibition, the value of Vmax is decreased. Since these inhibitors do not compete with the substrate, their activity is unaffected by substrate concentration. Since the inhibitor always affects a consistent proportion of the available enzyme, Vmax is reduced. However, Km remains the same since if Vmax, is reduced, Vmax/2 is reduced proportionally, and the amount of substrate required to reach this new, reduced Vmax/2 is the same as the original Km.
Why Km remain same in noncompetitive inhibition?
Noncompetitive inhibition is when the inhibitor does not compete with the substrate for the active site, but reduces enzyme activity by binding to another site (the allosteric site) on the enzyme. In noncompetitive inhibition, the inhibitor can combine with either the enzyme or the enzyme-substrate complex. In pure noncompetitive inhibition, the value of Vmax is decreased. Since these inhibitors do not compete with the substrate, their activity is unaffected by substrate concentration. Since the inhibitor always affects a consistent proportion of the available enzyme, Vmax is reduced. However, Km remains the same since if Vmax, is reduced, Vmax/2 is reduced proportionally, and the amount of substrate required to reach this new, reduced Vmax/2 is the same as the original Km.
noncompetitive inhibition
Noncompetitive inhibition is when the inhibitor does not compete with the substrate for the active site, but reduces enzyme activity by binding to another site (the allosteric site) on the enzyme. In noncompetitive inhibition, the inhibitor can combine with either the enzyme or the enzyme-substrate complex. In pure noncompetitive inhibition, the value of Vmax is decreased. Since these inhibitors do not compete with the substrate, their activity is unaffected by substrate concentration. Since the inhibitor always affects a consistent proportion of the available enzyme, Vmax is reduced. However, Km remains the same since if Vmax, is reduced, Vmax/2 is reduced proportionally, and the amount of substrate required to reach this new, reduced Vmax/2 is the same as the original Km.
Nuclear magnetic resonance
Nuclear magnetic resonance (NMR) spectroscopy aims to characterize a molecule's atoms. Specifically, this technique places a sample in a magnetic field. If the sample has a nuclear spin due to an odd number of protons or neutrons, then it will be affected by the magnetic field. The atomic nuclei will align with the field (a lower-energy state) or against the field (a higher-energy state). The frequency of the transition between these states, or resonance, is measured by NMR.
Nuclease
Nucleases are enzymes that cleave nucleic acids. There are two broad classes of nucleases that you should be aware of: exonucleases and endonucleases. Exonucleases cleave bases from the end of nucleic acid strands, and endonucleases cleave within a nucleic acid sequence. Additionally, ribonucleases in the cytosol degrade RNA.
Nucleic acids
Nucleic acids are involved in the storage and transmission of biological information. They are made up of nucleotides, which have three components: a nitrogenous base, a five-carbon sugar (ribose in RNA and deoxyribose in DNA), and at least one phosphate group. RNA contains uracil (U) instead of thymine (T) and is generally single-stranded, whereas DNA is generally double-stranded. DNA is used for the long-term storage of genetic information, while RNA is used for gene expression.
Ways to recognize nucleophile
Nucleophiles can often be recognized by the presence of at least one free pair of valence electrons, although nucleophilic attack can also take place using electrons from a pi or sigma bond. The factors that make a molecule a strong nucleophile include greater electron density—that is, more lone pairs and, if possible, more charge—and the lack of steric hindrance
Nucleophiles and Leaving group
Nucleosphiles are usually strong base and leaving group is usually weak base
Comp of reward system
Nucleus Accumbens, Hypothalamus, and Amygldala
Obediance
Obedience takes place when a person has the authority to directly compel someone to engage in a certain behavior. The scenario in the question does not describe direct requests or indicate that the behavior being described is strictly speaking mandatory, so this answer is not supported.
Positive beta decay
Positive beta decay, also known as positron emission, occurs when the proton-to-neutron ratio is too high. Negative beta decay occurs when neutron is converted to proton
Positive vs negative symptoms
Positive symptoms are symptoms that usually are not present in unaffected individuals, but are present in affected individuals. Negative symptoms are symptoms usually present in unaffected individuals, but not present in affected individuals.
Inter-rater reliability Next step
One other form of reliability is inter-rater reliability. That means that if an assessment is carried out by different researchers, they should generate similar results. For example, the SAT includes an essay that a person grades on a scale of 1-6. The SAT essay has good inter-rater reliability because the same essay will be given the same (or nearly the same) score regardless of which person scores it.
DNA repair
One of the DNA Polymerases involved in DNA repair removes the RNA primer and replaces the ribonucleotides with deoxyribonucleotides. Ligase then seals the gap in the sugar-phosphate backbone,
What is inter-rater reliability?
One other form of reliability is inter-rater reliability. That means that if an assessment is carried out by different researchers, they should generate similar results. For example, the SAT includes an essay that a person grades on a scale of 1-6. The SAT essay has good inter-rater reliability because the same essay will be given the same (or nearly the same) score regardless of which person scores it.
Observational Learning
Observational learning has 4 stages - attention to the behavior, memory of the behavior, ability or capability to behave similarly and motivation or drive to behave similarly.
Social cognitive theory basics
Observational learning, also sometimes referred to as social or vicarious learning, is the process of learning though watching others and imitating their behavior. Neurologically, mirror neurons, located in the frontal and parietal lobes, have a major role in observational learning: they fire when we perform an action but also when we observe someone else performing that same action. Mirror neurons function for physical actions as well as emotions, playing a role in human empathy. This concept is associated with social cognitive theory, which holds that our attitudes and behaviors are the result of observation of the attitudes and behaviors of others. According to this theory, we do not learn how to behave through trial-and-error or even conditioning, but rather through direct emulation of the other people and things that populate our environment.
Specific rotation
Observed rotation/conc of solution times tube length
Antisocial personality disorder (APD)
Of the four Cluster B personality disorders, the only condition that is characterized by a fixation on intentional malevolence or sadism is antisocial personality disorder.
Acetylation in histone
On a biochemical level, charge plays a major role in the interactions between histones and DNA. Histones are highly alkaline and are positively charged at physiological pH, which facilitates their interaction with the highly negatively charged phosphate groups on the backbone of DNA. Modifications like acetylation of histones reduce that positive charge, making histones interact with DNA less closely, which in turn facilitates transcriptional activity.
Histone-DNA interactions
On a biochemical level, charge plays a major role in the interactions between histones and DNA. Histones are highly alkaline and are positively charged at physiological pH, which facilitates their interaction with the highly negatively charged phosphate groups on the backbone of DNA. Modifications like acetylation of histones reduce that positive charge, making histones interact with DNA less closely, which in turn facilitates transcriptional activity.
Histones and DNA and charge
On a biochemical level, charge plays a major role in the interactions between histones and DNA. Histones are highly alkaline and are positively charged at physiological pH, which facilitates their interaction with the highly negatively charged phosphate groups on the backbone of DNA. Modifications like acetylation of histones reduce that positive charge, making histones interact with DNA less closely, which in turn facilitates transcriptional activity.
Hybridization and annealing
On the other hand, when two nucleic acid strands bind to form a double-stranded structure, the process is termed hybridization, or annealing. Like denaturation, annealing is also a step of the PCR cycle, although annealing takes place at a lower temperature (around 68°C). Hybridization also occurs in many biological processes; for example, short single-stranded RNA molecules termed small interfering RNA (siRNA) can hybridize with mRNA in a process that induces gene silencing. The siRNA-mRNA hybrid is recognized as an abnormal double-stranded RNA and is enzymatically cleaved, preventing its translation.
Oncogenesis
Oncogenesis is most often associated with mutations that occur by random chance (and elude the normal DNA repair machinery in the cell) or as a result of mutagenic compounds known as mutagens or carcinogens. (Examples of mutagens include ultraviolet light and certain chemicals, such as reactive oxygen species.) These mutations alter the functionality of crucial genes in the cell. However, oncogenesis is also associated with dysregulation of gene expression, as the abnormally elevated expression of genes involved in growth and proliferation can help contribute to the development of a tumor. The genes involved in oncogenesis can be divided into two groups: oncogenes and tumor suppressor genes. The basic difference between them is that oncogenes function to promote abnormal growth and proliferation, leading to cancer, while tumor suppressor genes function to prevent tumorigenic properties. Oncogenes can arise from the mutation of other genes, termed proto-oncogenes. If not mutated, proto-oncogenes do not promote cancer, but certain mutations or inappropriately elevated gene expression can effectively turn them into oncogenes.
Operant conditioning
Operant conditioning uses reinforcement to encourage a behavior and punishment to discourage it. An additional distinction is made between positive and negative reinforcements and punishments. "Positive" means adding a stimulus, and "negative" means removing one. Thus, positive reinforcement is adding a pleasant stimulus to encourage a behavior, while positive punishment is adding an unpleasant stimulus to discourage a behavior. Negative reinforcement is removing an unpleasant stimulus to encourage a behavior, while negative punishment is removing a pleasant stimulus to discourage a behavior.
Optical isomers
Optical isomers come in pairs and typically contain one or more chiral centers (a C atom bonded to four unique substituents). These substituents are arranged differently around the chiral carbon, in such a way that the molecule cannot be rotated to make the two arrangements match. If all of the chiral centers have different configurations, the isomers are non-superimposable mirror images (similar to your hands), known as enantiomers. Enantiomers have identical chemical and physical properties, but they differ in their rotation of plane-polarized light (opposite directions) as well as the products they yield when reacted with another chiral reagent. If the isomers have multiple chiral centers but differ only at some, they are known as diastereomers. Since diastereomers have very similar chemical, but less similar physical properties, the MCAT can drop subtle clues about how molecules were isolated and/or separated as indicators of whether compounds are enantiomers or diastereomers.
Osteoblast and Osteoclast
Osteoblasts function to build and repair bone, osteoclasts break down bone. Therefore, to increase calcium levels in the blood, osteoblast activity should be decreased and osteoclast activity should be increased to release stored calcium from the bone to the bloodstream.
Hormones that increase blood glucose levels
Other hormones can affect blood glucose levels as well. Cortisol (the main example of a class of hormones known as glucocorticoids) is released by the adrenal cortex. It is associated with long-term responses to stress and increases blood glucose levels. Epinephrine, which is released by the adrenal medulla and plays a major role in the fight-or-flight response to immediate stress, also raises blood glucose levels. In addition, growth hormone can increase blood glucose levels due to its antagonistic effects on insulin.
Oxidation and Electronegetivity
Oxidation state (which is measured using oxidation numbers) can be thought of as a method for keeping track of how electrons are shared within a molecule. Since all atoms have slightly different electronegativity values, it will always be the case that in a bond between atoms belonging to different elements, the electrons will be shared unequally.
Oxidation state
Oxidation states are essentially a model of electron distribution where we simplify things by assigning the electron to the more electronegative atom in a bond. Since oxidation states are a model of electron distribution, and electrons are charged, it is not surprising that the rules for determining oxidation states have some overlap with the charge of a molecule.
How does O2 transport through the body?
Oxygen enters the body in the lungs, where it diffuses through the alveoli into capillaries containing oxygen-poor blood brought to the lungs by the pulmonary arteries. Oxygen is carried through the blood to the tissues that require oxygen for respiration by hemoglobin, a metalloprotein that is composed of four heme-containing subunits. Hemoglobin exhibits cooperative binding, in which the first oxygen that binds to a heme group increases the affinity of the other heme groups for oxygen. Additionally, H +—high concentrations of which indicate an acidic environment—reduces the affinity of hemoglobin for oxygen, which allows hemoglobin to deliver oxygen to the tissues that need it.
Organic oxidation-reduction reactions
Oxygen-containing organic compounds exist on a spectrum of oxidation from alcohols (most reduced/least oxidized) to aldehydes/ketones (intermediate reduction/oxidation) to carboxylic acids (least reduced/most oxidized). A primary alcohol can be oxidized to an aldehyde by a mild oxidizing agent (such as PCC) or to a carboxylic acid by a strong oxidizing agent like NaCr2O7. A secondary alcohol will be oxidized to a ketone by either a mild or a strong oxidizing agent. A strong oxidizing agent will likewise oxidize an aldehyde to a carboxylic acid. A strong reducing agent, such as LiAlH4, can reduce a carboxylic acid directly to an alcohol, while weak reducing agents such as NaBH4 will not reduce carboxylic acids at all. A special agent, DIBAL, can reduce a carboxylic acid to an aldehyde when applied at a precise 1:1 ratio. Both mild and strong reducing agents can reduce aldehydes and ketones to primary and secondary alcohols, respectively.
Oxytocin
Oxytocin is involved in mood, but it is predominately implicated in bonding and intimacy interactions rather than appetite satiation.
Ray diagram and sign mnemonic
PRI and NVU mnemonics taught in the Altius Student Study Manual. Positive images are Real and Inverted, and Negative images are Virtual and Upright. Therefore, one must only identify one of these three characteristic and then the other two are known
PTH and calcitonin
PTH is secreted from the parathyroid in response to low blood calcium levels and elevates blood calcium levels by stimulating increased activity in osteoclasts, which are cells that break down bone, releasing calcium into the blood. Calcitonin has the opposite effect; it is released by the C cells of the thyroid and inhibits osteoclast activity. As a review, osteoblasts are cells that help build bone—and therefore reduce blood calcium levels by "storing" calcium in bone tissue—whereas osteoclasts are cells that break down bone, releasing calcium into the bloodstream.
Parapraxis
Parapraxis is a (Freudian) slip of the tongue, or unintended action, which might reveal a hidden thought.
Parkinson's disease
Parkinson's disease is a motor disorder characterized by stiff, rigid movements of the limbs, along with tremors, slowed movements, and impaired balance. The disease is caused by a loss of dopamine-producing cells in the brain. Dopamine is a neurotransmitter that transmits signals within the brain, so the coordination among nerve and muscle cells is disrupted in Parkinson's.
Passive immunity
Passive immunity is immunity generated when one receives antibodies from some outside source. The immune system of the person receiving the passive immunity is never directly activated. This can occur when a person is injected with antibodies developed against an antigen in another person or host,
What is passive immunity?
Passive immunity is the transfer of active humoral immunity in the form of ready-made antibodies, from one individual to another
Diabetes type II
Patients with type 2 diabetes are generally initially treated with dietary modifications and/or anti-hyperglycemic medications, but they may eventually require insulin treatment as well. Diabetes is commonly associated with high blood glucose levels (and uncontrolled diabetes can even be associated with excess glucose in the urine). Since insulin signaling promotes the uptake of glucose by cells, impaired insulin functioning will prevent cells from doing so, meaning that high levels of blood glucose will coexist with a state in which the cell has inadequate access to glucose for its own metabolism.
Modern racism
People are hesitant to share their true feelings in public if they know such beliefs are not acceptable
Incentive theory
People are motivated by the pleasure they feel when receiving an incentive, or external reward
Personality disorders
Personality disorders are characterized by long-lasting, maladaptive patterns of behavior that can impair cognition, emotion, interpersonal behavior and communication, and/or impulse control.
Personality Disorder
Personality disorders are seen to be relatively stable and thus a part of an individual's "personality."
Phosphodiester bonds
Phosphodiester bonds link the 3ʹ carbon atom of one deoxyribose and the 5ʹ carbon atom of another deoxyribose within the DNA molecules.
Ploidy #
Ploidy means the # of copies of a gene we have. humans are 2n. in mitosis, we are always 2n. in meiosis, we start off with 2n, then after reductional division (the first one), we have n (because we only have 1 copy of a gene after reductional division)
What is Ploidy?
Ploidy refers to how many copies of each chromosome a cell has. In humans, the vast majority of cells are diploid (2n), meaning that they contain two copies of each chromosome (except for the sex chromosomes; females have two X chromosomes and males have an X and a Y chromosome). Such cells are known as somatic cells—that is, the cells of the body. In contrast, germ cells (i.e., ova and spermatozoa) are haploid (n), meaning that the only have a single copy of each chromosome.
Chromosome
Ploidy refers to how many copies of each chromosome a cell has. In humans, the vast majority of cells are diploid (2n), meaning that they contain two copies of each chromosome (except for the sex chromosomes; females have two X chromosomes and males have an X and a Y chromosome). Such cells are known as somatic cells—that is, the cells of the body. In contrast, germ cells (i.e., ova and spermatozoa) are haploid (n), meaning that the only have a single copy of each chromosome. Aneuploidy results from having too many or too few copies of a given chromosome. This results from nondisjunction in anaphase during cell division. Having only one copy of a chromosome is known as monosomy, and having three copies is known as trisomy. Aneuploidy is commonly discussed as occurring in meiosis, and indeed, this is the only way for aneuploidy to be inheritable. For this reason, nondisjunction during meiosis is the cause of aneuploidies such as Down syndrome (trisomy 21) or Turner syndrome (monosomy X). However, nondisjunction during mitosis can also occur, and this is extremely common in cancer cells.
Point mutations
Point mutations are genetic mutations of a single nucleotide, which may be deleted, inserted, or replaced by another nucleotide. These mutations commonly occur when DNA polymerase incorrectly carries out base-pair matching, meaning that the corresponding mRNA codon synthesized from that DNA sequence will be off by one base, such as CAG instead of CGG. The effect of this varies depending on the specific location and outcome of the point mutation.
Mutations
Point mutations are genetic mutations of a single nucleotide, which may be deleted, inserted, or replaced by another nucleotide. These mutations commonly occur when DNA polymerase incorrectly carries out base-pair matching, meaning that the corresponding mRNA codon synthesized from that DNA sequence will be off by one base, such as CAG instead of CGG. The effect of this varies depending on the specific location and outcome of the point mutation. Silent mutations occur if the mutated codon codes for the same amino acid as the original codon. Such mutations have essentially no effect on the physiological function of the organism. An example would be GCU [alanine] → GCA [alanine]. Conservative point mutations are missense mutations that occur when the mutated codon codes for an amino acid that has similar functional properties (e.g., polarity and size) as the amino acid coded for by the original codon. An example would be GAU [aspartic acid] → GAG [glutamic acid]. Conservative point mutations are expected to have a relatively small effect on the functionality of the protein coded for by the gene. Non-conservative point mutations are missense mutations that occur when the mutated codon codes for an amino acid with dissimilar functional properties to the amino acid coded for by the original codon. An example would be GCG [alanine] → GAG [glutamic acid]. All things being equal, a non-conservative point mutation could be expected to have a significant impact on the functionality of the protein in question. Finally, nonsense mutations occur when the original codon is mutated into a stop codon. This truncates the translation process early and is generally associated with significant malfunctioning in the protein product of the gene, especially if a nonsense mutation occurs relatively early in the gene. The effects of most point mutations can be expected to be negative, but occasionally mutations result in more functional proteins. This is a major driver of evolution. Additionally, it is important to differentiate between somatic and germline mutations. Germline mutations take place in eggs and sperm (or their progenitor cells), and therefore are passed down to other generations. Somatic mutations take place in other body cells and are not passed down to other generations.
What is power in sociology?
Power is a very general term in sociology that refers, put simply, to an individual's ability to compel other people to do things. The social psychologists French and Raven defined multiple bases of power to capture the idea that power can stem from various sources and be exerted in diverse ways. Coercive power is the most direct form of power, and refers to power exerted through the threat of force. Reward power is the opposite side of that coin, referring to the ability to motivate action by promising rewards.
Power
Power is defined as work divided by time (P = W/t). Its units are watts (W), and 1 W = 1 J/s. The idea of power is essentially that a given amount of work could be expended either quickly or slowly, and that a system capable of doing so quickly is more "powerful" than a system in which the energy represented by a given amount of work is dissipated slowly. Rearranging the units of J/s indicates that power can also be expressed as a constant force multiplied by a constant velocity (P = Fv). Another important definition of power occurs in the context of circuits, where power is defined as current multiplied by voltage (P = IV). This is also derived from the general concept of power being work divided by time, but it is best memorized separately for the MCAT.
Transnational and transcriptional modifications
Protein modifications must be post-translational modifications. Such modifications can take place in a variety of locations within the cell, such as the interior of the endoplasmic reticulum or the cytoplasm. In contrast, post-transcriptional modifications (those performed on mRNA) occur in the nucleus; these include the addition of the poly(A) tail, the addition of the 5' cap, and splicing.
Pressure volume works
Pressure-volume diagrams are a visualization tool for the study of heat engines. Since work is done only when the volume of the gas changes, the diagram gives a visual interpretation of work done. Since the internal energy of an ideal gas depends upon its temperature, the PV diagram along with the temperatures calculated from the ideal gas law determine the changes in the internal energy of the gas so that the amount of heat added can be evaluated from the first law of thermodynamics. For a cyclic heat engine process, the PV diagram will be a closed loop. The area inside the loop is a representation of the amount of work done by the engine during a cycle.
Primary vs Secondary deviance
Primary deviance is deviance from a norm that is considered "acceptable" by society and does not result in any aggressive reactions that could cause ostracism. Secondary deviance from a norm, however, is not considered acceptable and often results in the individual being excluded from a group.
Primary vs secondary reinforcers
Primary reinforcers are consequences which are pleasurable in themselves, such as food. Secondary reinforcers (for example, money) are desirable because they are associated with primary reinforcers.
Primary and secondary socialization
Primary socialization refers to the learning of acceptable actions and attitudes during childhood, mostly from observation of our parents, siblings, friends, teachers, and other authority figures. Secondary socialization refers to the process of learning what is acceptable and appropriate in a smaller, more focused section of society. Learning how to behave at school or in the workplace are examples of secondary socialization.
Projection def
Projection involves a person taking their feelings about themselves and projecting them onto an external source. In this case, the boy is experiencing anxiety and frustration about being perceived as childish and irresponsible, and he projects those fears onto the puppy.
Projection
Projection is the process of attributing one's own undesired thoughts or feelings onto another person. For example, if you have a serious problem with your roommate, you will believe that your roommate has a serious problem with you.
Elements of gene expression
Promoters are regions of DNA that lie upstream to a given gene and initiate transcription by binding specific transcription factors that contribute to the binding of RNA polymerase. Additionally, expression is upregulated by enhancers, which are DNA sequences that can be located further from the gene of interest, and work by binding transcription factors that twist DNA into a hairpin loop, bringing distant regions into close proximity for transcription to begin. Silencers are the opposite of enhancers in eukaryotic cells; they are regions of DNA to which transcription factors known as repressors bind. Additionally, the methylation of C and A residues can reduce transcription. Methylation is associated with epigenetics, which refers to inheritable phenotypic changes involving mechanisms other than the alteration of the genome itself.
Promoter
Promoters are regions of DNA that lie upstream to a given gene and initiate transcription by binding specific transcription factors that contribute to the binding of RNA polymerase. Additionally, expression is upregulated by enhancers, which are DNA sequences that can be located further from the gene of interest, and work by binding transcription factors that twist DNA into a hairpin loop, bringing distant regions into close proximity for transcription to begin. Silencers are the opposite of enhancers in eukaryotic cells; they are regions of DNA to which transcription factors known as repressors bind. Additionally, the methylation of C and A residues can reduce transcription. Methylation is associated with epigenetics, which refers to inheritable phenotypic changes involving mechanisms other than the alteration of the genome itself.
Promoters
Promoters are regions of DNA that lie upstream to a given gene and initiate transcription by binding specific transcription factors that contribute to the binding of RNA polymerase. Additionally, expression is upregulated by enhancers, which are DNA sequences that can be located further from the gene of interest, and work by binding transcription factors that twist DNA into a hairpin loop, bringing distant regions into close proximity for transcription to begin. Silencers are the opposite of enhancers in eukaryotic cells; they are regions of DNA to which transcription factors known as repressors bind. Additionally, the methylation of C and A residues can reduce transcription. Methylation is associated with epigenetics, which refers to inheritable phenotypic changes involving mechanisms other than the alteration of the genome itself.
postconventional level Kohlbergs
Promoting social welfare indicates moral reasoning at the postconventional level, according to Kohlberg's theory.
Protease
Proteases function to digest proteins into smaller fragments.
Protein folding and water
Protein folding is assisted by water, which forms a solvation layer, bringing polar residues to the outside and pushing nonpolar residues inside to form hydrophobic pockets
Alpha carbon
Protons on the alpha carbon adjacent to a carbonyl exhibit a dramatic increase in acidity. This increase in acidity is due mostly to resonance in the conjugate base, which stabilizes the carbanion formed by abstraction of the proton. The more effective the resonance stabilization, the stronger the acidity of the original proton.
Proximal stimulus
Proximal stimulus is the stimulus registered by the sensory receptors (e.g., the pattern of light falling on the retina)
Primary appraisal phase
Psychologists teach that when a person is first confronted with a potential threat or stressor, the individual will immediately enter a primary appraisal phase. During this time, they will categorize the threat as either irrelevant, benign-positive, or stressful. If they determine that it is stressful, they will move to the secondary appraisal phase during which time they will evaluate whether or not they have the resources necessary to deal with or dispatch the threat.
RNA polymerase
RNA polymerase is not used in cDNA cloning
RNA polymerase and its function
RNA polymerase is the enzyme responsible for RNA synthesis. In eukaryotes, it binds to a promoter region upstream of the start codon with the assistance of transcription factors, the most important of which is the TATA box. RNA polymerase travels along the template strand in the 3'-5' direction, synthesizing an antiparallel complement in the 5'-3' direction. The template strand is known as the antisense strand, and the opposite strand is known as the sense strand, because it corresponds to the codons on the mRNA that is eventually exported to the cytosol for translation.
Rapid-eye-movement (REM)
Rapid-eye-movement (REM) sleep occurs. During REM sleep, very little skeletal movement takes place. In fact, during REM sleep, brainwaves, heart rate, and respiration rate are very similar to what is observed when a person is awake. REM is also the stage when a person typically dreams.
Rapidly dividing cells
Rapidly dividing cells undergo mitosis under the influence of specific signaling molecules. These molecules are expressed when their genes are transcribed, then are translated into proteins. In order to gain the best understanding of how a signaling protein's levels are regulated, both the protein and mRNA levels would need to be studied. Western blotting gives us information about the amount of protein expressed in a cell, while RT-PCR gives us information about the amount of RNA expressed.
Recrystallization??
Recrystallization is used to purify a solid product that contains impurities. This process involves the dissolution of the solid in a solvent and subsequent heating. The solid then dissolves and is cooled, causing it to solidify (crystallize) again. As the lattice structures of solids tend to exclude impurities, each subsequent recrystallization results in a progressively purer compound.
What is Recrystallization?
Recrystallization is used to purify a solid product that contains impurities. This process involves the dissolution of the solid in a solvent and subsequent heating. The solid then dissolves and is cooled, causing it to solidify (crystallize) again. As the lattice structures of solids tend to exclude impurities, each subsequent recrystallization results in a progressively purer compound.
Electrochemical cells
Redox reactions can be carried out in special devices known as electrochemical cells. These cells must have two electrodes, which are where the redox half-reactions occur. The electrode where oxidation happens is known as the anode, while the electrode where reduction happens is known as the cathode. Therefore, a surplus of electrons is generated at the anode (because electrons are lost during oxidation), and they travel to the cathode. In a galvanic (or voltaic) cell, a spontaneous redox reaction is used to generate a positive potential difference that can drive current. The total standard potential generated by a cell, Ecell, can be calculated from the standard reduction potentials of the half-reactions. The simplest way of defining Ecell is presented below: Ecell = E°cathode − E°anode In contrast to a galvanic cell, an electrolytic cell uses a connected power source to conduct a nonspontaneous redox reaction. While galvanic cells have positive Ecell values (indicating spontaneity), electrolytic cells are characterized by negative Ecell values.
Material capital info
Related to financial capital, material capital refers to any inanimate physical objects that one can obtain within society (i.e. "things"). Resources like metal, timber, fossil fuels, buildings, bridges, and other pieces of societal infrastructure such as computers and technology are considered material capital.
Relative poverty
Relative poverty refers to social disadvantage by income or wealth as compared to the social advantages linked to income or wealth in a society.
What is reliability?
Reliability refers to how consistent and repeatable an experiment or assessment is. Test-test reliability refers to the fact that a good test should give stable results over time. For example, if you took the MCAT once a year every year without doing any prep or practice, you would get basically the same results every time because the MCAT has good test-test reliability.
Reliability
Reliability refers to how consistent and repeatable an experiment or assessment is. Test-test reliability refers to the fact that a good test should give stable results over time. For example, if you took the MCAT once a year every year without doing any prep or practice, you would get basically the same results every time because the MCAT has good test-test reliability. One other form of reliability is inter-rater reliability. That means that if an assessment is carried out by different researchers, they should generate similar results.
Suppression/Repression
Repression is the act of pushing undesired or unacceptable thoughts and urges into the unconscious. The conscious, deliberate form of repression is known as suppression or denial and is typically used to willfully forget an emotionally painful experience.
Repression
Repression is the process the ego uses to push undesired or unacceptable thoughts and urges down into the unconscious. The conscious, deliberate form of this is known as suppression or denial, and is typically used to willfully forget an emotionally painful experience or event. Regression is the unconscious process of reverting back to behaviors that are less sophisticated and often associated with children (sucking one's thumb, wetting the bed).
Repression (defense mechanism)
Repression is the process the ego uses to push undesired or unacceptable thoughts and urges down into the unconscious. The conscious, deliberate form of this is known as suppression or denial, and is typically used to willfully forget an emotionally painful experience or event. Regression is the unconscious process of reverting back to behaviors that are less sophisticated and often associated with children (sucking one's thumb, wetting the bed).
Cognitive dissonance
Research on cognitive dissonance has found that people tend to change their attitudes to match their behaviors, rather than change their behavior.
Resocialization
Resocialization is the process through which we get rid of old behaviors in order to take on new ones. The training of soldiers to obey orders and behave within the rigorous confines of military life is an example of resocialization.
Restriction enzymes cleave DNA
Restriction enzymes cleave DNA at very specific locations, or recognition sites, which vary from enzyme to enzyme. These sites correspond to sequences of 4 to 8 bases. Recognition sites usually contain some degree of symmetry, often in the form of palindromic sequences. In a palindromic sequence, the sequence of bases when read from 5′ to 3′ on one strand is the same as the sequence of the other strand when it is read from 5′ to 3′. When a restriction enzyme cleaves a DNA sequence vertically across the recognition site, the resulting fragments have "blunt" ends, whereas "sticky" ends result from restriction enzymes that cleave a DNA sequence in a zig-zag fashion. For example, the double-stranded sequence below represents the restriction site of the enzyme EcoRI. This site is cleaved after the guanine on both strands, resulting in sticky ends:
Restriction enzymes
Restriction enzymes, also known as restriction endonucleases, occur in nature in prokaryotes and archaea. In these organisms, they act as a defense system against invading viruses by cleaving foreign DNA. This activity is utilized in the laboratory to cleave target DNA, fragments of which can then be ligated together in a process termed genetic recombination.
Retrograde amnesia
Retrograde amnesia refers to forgetting memories that occurred prior to the injury or insult
Reverse transcriptase
Reverse transcriptase is an RNA-dependent DNA polymerase and, as such, it will generate a DNA molecule.
Rf value
Rf is equal to the distance the compound of interest traveled along the plate divided by the distance traveled by the solvent front. A sample TLC plate, with those distances labeled, is shown below. Note that A, B, and C represent arbitrary compounds in this image.
Roles of ribosomes
Ribosomes themselves are not membrane-bound organelles, and they are not unique to eukaryotes (although prokaryotic ribosomes have a different structure). They play the crucial role of protein translation. Once proteins are synthesized, the Golgi apparatus modifies them and packages them into membrane-bound vesicles that are then sent to the ultimate destination of the proteins.
SES (socioeconomic status)
SES reflects an individual's position in the social hierarchy, as understood in terms of how that hierarchy is structured. SES attempts to quantify an individual's access to resources, such as material goods, money, power, social networks, healthcare, and education. It is access to these resources that enables individuals and/or groups to prosper in the social world.
SN2 reaction info
SN2 reactions are even simpler, as they take place in a single step. In this mechanism, the strong nucleophile displaces the leaving group by attacking from the rear, often described as a "backside attack." This reverse attack inverts the relative stereochemistry of the molecule. (The absolute stereochemistry - namely R vs. S configuration - is inverted as well, provided that the priority of the nucleophile matches the priority of the leaving group, which is nearly always the case.) For a brief instant before the leaving group fully dissociates, the central carbon of the substrate is at least partially bound to five substituents. This high-energy state is known as a pentavalent transition state. With everything happening at once, steric hindrance is a major limiting factor of SN2 reactions, with primary substrates reacting the most rapidly.
Sanger sequencing
Sanger sequencing works by using a DNA nucleotide without a 3' hydroxyl to 'poison' the reaction. Because the normal DNA sugar is referred to as "deoxyribose," this sugar without either a 2' or a 3' hydroxyl group is called "dideoxyribose.
Saponification
Saponification is a special case of acid-base chemistry involving carboxylic acids (Latin sapo means "soap," so this literally means something like "soapification"). Under basic conditions (e.g., when mixed with NaOH or KOH), carboxylic acids are deprotonated and their conjugate bases form salts, according to the following template: RCOOH + Na+ + OH− → RCOO−Na+ + H2O. The acid-base chemistry of this process is straightforward, although it is worth noting that the process can be combined with the base-catalyzed hydrolysis of a triglyceride containing three fatty acid chains.
Schachter-Singer theory
Schachter-Singer theory, thus stated that a stimulus first leads to physiological arousal, then a cognitive interpretation of the circumstances, and finally a perception of emotion.
Scehma
Schematic processing is relevant to explaining response times during the IAT because the speed with which memory schemas (organized clusters of knowledge) are activated and processed is presumed to indicate the participant's implicit attitude.
Schwann cells
Schwann cells are the myelin-forming cells in the peripheral nervous system.
Secure attachment
Secure attachment refers to when a child has a constant caregiver and is therefore able to explore and learn about the world, knowing he or she has a secure, constant base to return to. Secure attachment is considered crucial to healthy social development.
All self concepts ideas
Self-concept is an individual's mental model of his or her abilities and attributes. Self-efficacy is the belief that one can perform adequately in a particular situation. Self-esteem, often analogized to self-image, is the attitude which influences moods and exerts a powerful effect on an individual's personal and social behaviors. Self-fulfilling prophecy is the phenomenon wherein an individual believes an event will occur and, consciously or unconsciously, behaves in such a way as to bring about this prediction. The prophecy can be positive or negative. Self-handicapping is the process of developing (anticipating failure) behavioral reactions and explanations that minimize personal responsibility for the failure. Self-perception theory posits that people observe themselves in order to figure out the reasons they act as they do. Self-serving bias is a set of biases in which people take credit for their successes and deny responsibility for failures.
Self-esteem vs Self-efficacy
Self-esteem is a global feeling about yourself whereas self-efficacy refers to how you feel about yourself in various situations
What is Self-handicapping?
Self-handicapping is the process of developing (anticipating failure) behavioral reactions and explanations that minimize personal responsibility for the failure.
Self-image
Self-image is one's persistent mental picture of one's own appearance, especially observable physical traits such as height, weight, hair color, etc.
What is self-perception?
Self-perception theory posits that people observe themselves in order to figure out the reasons they act as they do.
Sensitive period
Sensitive period (also referred to as a critical period), which identifies a point in early development that can have a significant influence on physiological or behavioral functioning in later life.
Sensory memory
Sensory memory is the initial recording of encoded sensory information, and is therefore the most fleeting form of memory storage. There are two main types of sensory memory: iconic memory, responsible for visual information and lasting only a few tenths of a second, and echoic memory, responsible for auditory information and lasting 3 to 4 seconds.
Sensory memory types
Sensory memory is the initial recording of encoded sensory information, and is therefore the most fleeting form of memory storage. There are two main types of sensory memory: iconic memory, responsible for visual information and lasting only a few tenths of a second, and echoic memory, responsible for auditory information and lasting 3 to 4 seconds.
What is sensory memory?
Sensory memory is the initial recording of encoded sensory information, and is therefore the most fleeting form of memory storage. There are two main types of sensory memory: iconic memory, responsible for visual information and lasting only a few tenths of a second, and echoic memory, responsible for auditory information and lasting 3 to 4 seconds.
Types of memory
Sensory memory is the initial recording of encoded sensory information, and is therefore the most fleeting form of memory storage. There are two main types of sensory memory: iconic memory, responsible for visual information and lasting only a few tenths of a second, and echoic memory, responsible for auditory information and lasting 3 to 4 seconds. Short-term memories last closer to 30 seconds without repetition. Moreover, the short-term memory can typically only handle about seven pieces of information at once. Short-term memory can be bolstered by various mnemonic devices. Working memory is the element of short-term memory that allows us to consciously process and manipulate a few pieces of information. It involves an interplay between short-term memory, attention, and the executive function of the brain. Finally, information can proceed to long-term memory, which is currently theorized to have a potentially infinite capacity. Long-term memory is divided into implicit memory, also known as nondeclarative memory, and explicit memory, also known as declarative memory. Implicit (nondeclarative) memory accounts for acquired skills and conditioned responses to circumstances and stimuli. This also includes procedural memory, which accounts for motor skills and specific physical actions. The cerebellum plays a primary role in encoding implicit memories. Explicit (declarative) memory accounts for memories that we must consciously recall with effort and focus. A further division within explicit memory is between episodic memory, which accounts for our experiences, and semantic memory, which accounts for facts and concepts that we know. The hippocampus plays a primary role in encoding explicit memories.
Sensory receptors
Sensory nerve pathways begin with sensory receptors, which can be divided into the following types. Hair cells (hearing; linear and rotational acceleration) respond to movement of fluid in the inner ear. Olfactory receptors (smell) respond to volatile compounds in the air. Osmoreceptors (water homeostasis): respond to the osmolarity of blood. Nociceptors (somatosensation, a.k.a. touch): respond to painful stimuli. Photoreceptors (sight) respond to the visible spectrum of electromagnetic waves. Taste receptors (taste) respond to dissolved compounds in substances. These receptors can also be broadly divided into exteroceptors, which respond to stimuli from the outside world, and interoceptors, which respond to stimuli generated within the body.
Sensory receptors types
Sensory nerve pathways begin with sensory receptors, which can be divided into the following types. Hair cells (hearing; linear and rotational acceleration) respond to movement of fluid in the inner ear. Olfactory receptors (smell) respond to volatile compounds in the air. Osmoreceptors (water homeostasis): respond to the osmolarity of blood. Nociceptors (somatosensation, a.k.a. touch): respond to painful stimuli. Photoreceptors (sight) respond to the visible spectrum of electromagnetic waves. Taste receptors (taste) respond to dissolved compounds in substances. These receptors can also be broadly divided into exteroceptors, which respond to stimuli from the outside world, and interoceptors, which respond to stimuli generated within the body.
Universal emotions
Seven universal human emotions: anger, contempt, disgust, fear, happiness, sadness, and surprise.
azimuthal or angular momentum quantum number
The azimuthal, or angular momentum, quantum number (l) describes the subshell of the principal quantum number in which the electron is found, with values ranging from 0 to n − 1, where l = 0 is the s subshell, l = 1 is the p subshell, l = 2 is the d subshell, and l = 3 is the f subshell.
Theories of emotions
Several theories seek to explain how the cognitive and physiological aspects of emotion are connected. An early theory of emotion, the James-Lange theory, hypothesized that a stimulus triggers a physiological response, which then leads to the subjective, conscious experience of emotion. For example, if you are watching a scary movie, your heart rate may become elevated, and that leads to the perception of fear. However, this theory is limited, since certain physiological states may be experienced as different emotions depending on context (such as either fear or excitement). A second theory, the Cannon-Bard theory, posited that cognitive and physiological responses to a stimulus occur simultaneously and independently of one another, with a behavioral response following them. However, this theory still lacks any element of cognitive appraisal, or conscious thought about how one's situation may impact the emotion(s) felt. A third theory, the Schachter-Singer theory, thus stated that a stimulus first leads to physiological arousal, then a cognitive interpretation of the circumstances, and finally a perception of emotion. This resembles the James-Lange theory, but adds the element of cognitive appraisal, which helps explain how (for example) an elevated breathing rate can be interpreted as multiple different emotions based on context.
Sex and gender
Sex refers to the biologically determined sex chromosomes of a person and the accompanying anatomy (the XX genotype corresponds to females and the XY genotype corresponds to males), while gender is a culturally conditioned phenomenon.
sexual dimorphism
Sexual dimorphism is the condition where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs.
Shock waves (sonic booms)
Shockwaves is produced when fluid molecules rapidly pressurized, and this high pressure region propagates throughout the medium
Short wavelength
Short wavelength are necessary to obtain good/higher resolution of small structures. It also means higher frequency
What is short-term memory (STM)?
Short-term memories last closer to 30 seconds without repetition. Moreover, the short-term memory can typically only handle about seven pieces of information at once. Short-term memory can be bolstered by various mnemonic devices. Working memory is the element of short-term memory that allows us to consciously process and manipulate a few pieces of information. It involves an interplay between short-term memory, attention, and the executive function of the brain.
short-term memory (STM)
Short-term memories last closer to 30 seconds without repetition. Moreover, the short-term memory can typically only handle about seven pieces of information at once. Short-term memory can be bolstered by various mnemonic devices. Working memory is the element of short-term memory that allows us to consciously process and manipulate a few pieces of information. It involves an interplay between short-term memory, attention, and the executive function of the brain.
Sigmund Freud ego
Sigmund Freud defined the ego as the principle which drives to please the id in realistic ways that will provide benefit (and reduce grief) in the long term. It has the capacity to act through the conscious mind (i.e., awareness at the present moment), the unconscious mind (i.e., processes that occur automatically in the mind and are not available to introspection), and the preconscious mind (i.e., thoughts in the minds that are unconscious but can be recalled if necessary).
DNA acetylation
Since DNA is negatively charged due to its phosphate backbone, the charge on lysine allows for tight histone-DNA interactions thanks to electrostatic attraction between the charged atoms on each molecule. Acetylation of lysine makes the residue neutral, lessening these interactions and promoting a looser structure. Loose chromatin structure is typically associated with euchromatin, the less dense, transcriptionally active chromatin structure that appears light under a microscope. In contrast, histone deacetylation will restore the positive charge to the residue, allowing the electrostatic attractions to return
Vmax and Km in Noncompetitive inhibition
Since the inhibitor always affects a consistent proportion of the available enzyme, Vmax is reduced. However, Km remains the same since if Vmax, is reduced, Vmax/2 is reduced proportionally, and the amount of substrate required to reach this new, reduced Vmax/2 is the same as the original Km.
Situational poverty
Situational poverty is a transitional poverty caused by a single life event, often a natural disaster or other major adversity. If there is no change in employable skills or willingness to work, it is likely that persons in situational poverty will transition back to their previous income levels.
Social stratification
Social stratification is most commonly understood through the separation of people and/or groups by three social identifiers. Social class implies having or not having access to capital, social or otherwise. Examples include the degree of privilege, power, rights over others, authority, or self-determination the individual has. Racial and ethnic stratification refers to inequalities between fixed groups, such as the shared genetic ancestry and physical traits of race, or the shared cultural, behavioral, or religious characteristics of ethnicity. Gender is the patterning of difference and domination through distinctions between women and men. Gender roles are social constructions: they contain self-perceptions, psychological traits, and roles assigned to each sex.
Basal Ganglia
The basal ganglia are involved in several functions, including voluntary movement, habitual behaviors, learning, and emotion.
Social capital
Social capital refers to societal connections. It is of primary importance in politics, business, and community organizing. This capital can be exercised as favors, decisions, or even monetary compensation. Structural social capital is the components of social structure that create opportunities for achieving social goals. It gives structure and stability to social transactions. This form of capital does not just include norms or social mores, but is built from the bases of culture and institutions within society. In contrast, cognitive social capital describes the shared norms, values, attitudes, and beliefs of a people who seek mutually beneficial group action.
Social cognitive theory
Social cognitive theory (originally referred to as social learning theory) suggests that behaviors are learned through observing others and modeling their actions.
Conformity
Social conformity, or just conformity, is the tendency for individuals to adopt the behaviors, attitudes, and values of other members of a reference group. A reference group is any social group to which the individual can be socially compared. An individual's degree of social conformity can be thought of as indicating how "normal" they act, but a more accurate statement is that conformity indicates the degree to which an individual's behavior corresponds to expected social norms, rules, and customs.
Social control
Social control is defined as the ways in which society can prevent and sanction behavior that violates social norms.
Social epidemiology
Social epidemiology focuses on the contribution of social and cultural factors to disease patterns in populations. It is also well positioned to supplement the biomedical approach because social epidemiology is a sub-field of epidemiology.
Social escapism
Social escapism is the avoidance of unpleasant, boring, difficult, or anxiety-inducing aspects of daily life. While economically depressed individuals are more likely to wish to escape their lives, this would be unlikely to cause an individual to perceive more crime.
Social exchange theory
Social exchange theory views society as a series of interactions that are based on estimates of rewards and punishments. Similar to rational choice theory, social exchange posits that interactions are determined by the rewards or punishments that we receive from others. For example, if a relationship partner become "more trouble than he or she is worth," the person may decide to end the relationship
Social facilitation
Social facilitation is the tendency that people have to perform simple tasks better or more efficiently when in the presence of other people. Inversely, when performing a complex or new task, the presence of others can hinder one's performance. In contrast, social loafing is the tendency that people have to put in less effort in a group setting, particularly if the group is being evaluated as a whole and not on an individual basis.
Social influence
Social influence theory attempts to explain why the degree of change achieved by influence can vary based on how the influenced individual processes and accepts the outside "forces." There are three main ways in which people respond to external influences. Compliance occurs when individuals accept the influence—typically in response to a direct request—and adopt the behavior to gain rewards and/or avoid punishments. In the context of conformity, identification takes place when individuals accept an influence or viewpoint without deep reflection in order to produce or maintain a desired and beneficial relationship to another person or a group. Internalization occurs when individuals accept an influence and come to identify with a given behavior or mindset. Social proof refers to a phenomenon in which an individual adopts the behaviors of others—typically without a direct request being made—on the assumption that others' behavior must be correct under the circumstances at hand.
A social learning theorist
Social learning theory suggests that learning occurs through observation of others; therefore, if a child spends time watching characters in violent video games or movies shooting other people, he or she will potentially learn and reproduce that sort of behavior
Social Loafing
Social loafing refers to the fact that people are more productive alone than in a group. Research also suggests that individuals are less critical and less creative in groups.
Socialization
Socialization is the lifelong process through which people inherit, develop, and disseminate social norms, customs, and belief systems. It is through socialization that we develop the habits and skills necessary for successfully living in society
social constructive perspective
Socially constructive perspective is based upon expectations of others
Socioeconomic status (SES)
Socioeconomic status (SES) is a term that is familiar, but often misunderstood. SES reflects an individual's position in the social hierarchy, as understood in terms of how that hierarchy is structured. SES attempts to quantify an individual's access to resources, such as material goods, money, power, social networks, healthcare, and education. It is access to these resources that enables individuals and/or groups to prosper in the social world.
Solomon Asch
Solomon Asch conducted an experiment investigating the extent to which social pressure from a majority group could influence a person to conform. Asch used confederates who were instructed to give clearly incorrect answers regarding the lengths of various lines. He then measured the number of times each unknowing participant conformed to the majority view. In Asch's study, the confederates never provided an explanation for their choices to the group.
Solomon Asch's conformity experiment
Solomon Asch's conformity experiment demonstrated that individuals often conform to a group view, even when the group view differs from a clearly correct answer. Asch used a task in which a participant, along with several of Asch's confederates, were told to judge the relative lengths of drawn lines. The confederates would give a clearly-incorrect opinion regarding which line was shorter or longer, causing the participant (who did not know that the others in the room were "in on it") to conform to this incorrect view in some cases.
Solvents effect on SN1 vs SN2
Solvents have a notable effect on the rates of these reactions. Polar protic solvents (such as water and ethanol) tend to stabilize ions in solution. Since they can stabilize the carbocation, these protic solvents are best used for SN1 reactions. However, SN2 reactions rely not on a carbocation, but on a strong nucleophile displacing the leaving group. Protic solvents tend to stabilize (weaken) this nucleophile, so they should not be used for SN2 procedures. Instead, polar aprotic solvents, such as acetone, are a better choice.
Somatic disorders basics
Somatic disorders are unified by somatic (bodily) symptoms that can cause stress and impairment to the sufferer. These symptoms generally lack an identifiable physical cause. Alternatively, the individual may be impaired by irrational fears of developing or having a disease, as in illness anxiety disorder
Somatic disorders
Somatic disorders are unified by somatic (bodily) symptoms that can cause stress and impairment to the sufferer. These symptoms generally lack an identifiable physical cause. Alternatively, the individual may be impaired by irrational fears of developing or having a disease, as in illness anxiety disorder.
Somatic disorders info
Somatic disorders are unified by somatic (bodily) symptoms that can cause stress and impairment to the sufferer. These symptoms generally lack an identifiable physical cause. Alternatively, the individual may be impaired by irrational fears of developing or having a disease, as in illness anxiety disorder.
Simple and facilitated diffusion
Some molecules, like small gases, can directly diffuse through the membrane. This is known as simple diffusion, and is an example of passive transport because no energy is necessary. Osmosis is a type of simple diffusion in which water moves in or out of the cell to attempt to equalize concentrations of solute. Facilitated diffusion is another form of passive transport where no energy is necessary because molecules diffuse down their concentration gradient, but a transmembrane channel is necessary because the molecule may be too large or polar for simple diffusion. Ions are often transported through facilitated diffusion, and aquaporins are facilitated diffusion channels for water that augment osmosis.
Source Amnesia
Source amnesia is the inability to remember where, when or how previously learned information has been acquired, while retaining the factual knowledge.
Southern/Northern/Western blotting
Southern blotting is a technique used to identify specific DNA sequences. Western and northern blots are used to identify protein and RNA sequences, respectively. In these sequences, the molecules of interest undergo gel electrophoresis to separate them by size and then are transferred to a nitrocellulose membrane that can be heated, at which point probe analysis can be performed. (The process is slightly different for western blots, where antibodies are used instead of DNA/RNA probes.)
Spermatids
Spermatids initially lack some of the most important features of the mature sperm cells that are released during ejaculation, and they gain those features in a process known as spermiogenesis. The main events of spermiogenesis are as follows: (1) formation of the acrosomal cap, which facilitates the ability of a sperm to fertilize an egg; (2) formation of a tail; and (3) loss of excess cytoplasm. Spermiogenesis results in non-mature spermatozoa that are incapable of independent movement, and are transferred to the epididymis to undergo maturation.
Spermatogenesis
Spermatogenesis is initiated during puberty and continues throughout the lifespan. The process of spermatogenesis takes approximately 3 months, and approximately 100 million viable sperm are produced daily. Spermatogenesis begins with spermatogonial stem cells and ends with mature spermatozoa, but has several intermediate stages.
Spermatogonia
Spermatogonia divide through mitosis into two primary spermatocytes. Primary spermatocytes go through meiosis I and divide into two secondary spermatocytes. This is where the transition from diploid (2n) to haploid (n) happens. Secondary spermatocytes then go through meiosis II, forming spermatids. A total of four genetically unique spermatids are formed from each primary spermatocyte.
Spiritual capital
Spiritual capital reflects the feelings, attitudes, and fulfilling beliefs that an individual holds while practicing their formal religion or any form of personal spirituality he or she uses as a way to connect with the world around them. Spiritual capital is similar to intellectual capital, but is deeper, more personal, and less quantifiable.
Splicing
Splicing explains why there are over 200,000 proteins in the human body, but only approximately 20,000 genes. Splicing is carried out by the spliceosome, a combination of small nuclear RNAs (snRNAs) and protein complexes.
Spontaneity and Keq
Spontaneity can also be defined in terms of other chemical concepts. By definition, a spontaneous reaction will lead to more products being present than reactants. This means that the equilibrium constant (Keq), which is broadly defined as [products]/[reactants], will be greater than 1 for a spontaneous reaction. This relationship is encoded in the equation ∆G°rxn = −RTlnKeq. Additionally, in the context of electrochemical cells, spontaneous reactions are associated with positive cell potentials (E° > 0). On Test Day, it is important to automatically recognize that spontaneity is equivalent to ∆G < 0, Keq > 1, and E° > 0.
Stablizing selection
Stabilizing selection occurs if both extremes are selected against, directional selection occurs if only one extreme phenotype is selected against and the other extreme is favored, and disruptive selection occurs when the median phenotype is selected against.
Stage I sleep
Stage 1 sleep primarily shows theta waves (low amplitude, irregular frequency). In this stage, rolling movement of the eyes occurs with moderate skeletal muscle activity.
Stage 3 and 4 sleeps
Stage 3 sleep marks the transition into slow-wave sleep, which includes both Stage 3 and Stage 4. In this stage, delta waves (high amplitude, low frequency) predominate. As Stage 3 progresses, higher-frequency waves disappear and Stage 4 sleep begins. During Stage 4, digestion and heart rate slow and growth hormones are released.
Static friction
Static friction (or Fstatic) acts to oppose the motion of objects that are "static," or not sliding along a surface. The equation for static friction is Fstatic ≤ μsN, which has two key differences from the kinetic friction equation. First, it includes μs, or the coefficient of static friction. Like μk, μs is typically given whenever its value is required to solve an MCAT question. In most situations, μs is larger than μk, which reflects the idea that it is more difficult to make an object begin sliding than to keep it sliding. Second, this equation includes a less than or equal to sign. The reason for this is simple: static friction can never have a value greater than the net force that it opposes. For example, imagine that you are trying to push a heavy, stationary box. If a tiny forward push of 4 N does not move the box, static friction must be exerting a force of 4 N in the opposite direction. If it were greater than 4 N, the object would move backwards, and friction does not cause objects to move! However, if a larger push of 20 N is also unsuccessful, this means that static friction now exerts a force of 20 N. As such, static friction increases to oppose the force of motion until it reaches its maximum value (μsN). If the force of motion exceeds this value, the object will start to slide.
Statistical significance and P-value
Statistical significance is expressed using p-values, which express the likelihood of a certain result being due to chance given a certain null hypothesis, which usually refers to the absence of a relationship between the variables of interest. A p-value <0.05 indicates that there is a <5% chance of the observed relationship being due to chance, and this is the most commonly used threshold for deeming a result statistically significant. The power of a study refers to the ability of a study design to detect a real statistically significant effect, and it is primarily affected by the size of the study (larger samples have more power) and the size of the effect (larger effects are easier to identify).
p-value < 0.05
Statistical significance is expressed using p-values, which express the likelihood of a certain result being due to chance given a certain null hypothesis, which usually refers to the absence of a relationship between the variables of interest. A p-value <0.05 indicates that there is a <5% chance of the observed relationship being due to chance, and this is the most commonly used threshold for deeming a result statistically significant. The power of a study refers to the ability of a study design to detect a real statistically significant effect, and it is primarily affected by the size of the study (larger samples have more power) and the size of the effect (larger effects are easier to identify).
Process of transcription?
The DNA helix must be unzipped for transcription to take place, which means that some of the same machinery used for DNA replication has to be engaged, especially enzymes like helicase and topoisomerase. RNA polymerase is the enzyme responsible for RNA synthesis. In eukaryotes, it binds to a promoter region upstream of the start codon with the assistance of transcription factors, the most important of which is the TATA box. RNA polymerase travels along the template strand in the 3'-5' direction, synthesizing an antiparallel complement in the 5'-3' direction. The template strand is known as the antisense strand, and the opposite strand is known as the sense strand, because it corresponds to the codons on the mRNA that is eventually exported to the cytosol for translation.
Stereoisomers
Stereoisomers involve different ways that substituents can be positioned. Cis-trans isomerism on the MCAT most frequently involves alkene bonds. Rotation about pi bonds is restricted, meaning that two different groups of atoms attached to each carbon of the C=C bond can be arranged in different ways to give different molecules. These atoms or groups can be given priorities, with atoms with higher atomic numbers given higher priorities. If the highest-priority groups for each carbon are on the same side of the molecule, that molecule is denoted as the cis or Z isomer. If they are on opposite sites, the isomer is trans or the E isomer. Cis-trans isomers generally have similar chemical but different physical properties.
Sterotype boost, prejudice, and confirmation bias
Stereotype boost (also known as stereotype lift) occurs when positive stereotypes about social groups cause improved performance. For example, Asians reminded of the stereotype "Asians are good at math" before completing a math test tend to outperform Asians who are not first reminded of this stereotype. This passage does not discuss improved performance as a result of a positive stereotype. Prejudice refers to preconceived ideas and beliefs about people or groups based on their group membership. Discrimination is the unequal treatment of individuals or groups on the basis of group membership. Confirmation bias is a type of cognitive bias (common error in thinking) in which individuals tend to embrace evidence supporting their beliefs, dismiss or ignore evidence refuting their beliefs, and interpret ambiguous evidence as support. Prejudice may cause an individual to act in a discriminatory fashion, creating the conditions for confirmation bias.
Structural isomers
Structural isomers describe the different ways that the atoms in a compound can be connected. The three main subcategories of structural isomers are chain isomers, functional isomers, and positional isomers. Chain isomers have different arrangements of the carbon 'skeleton.' Functional isomers are isomers where the molecular formula remains the same, but the type of functional group in the atom is changed. For example, a compound with an oxygen atom in addition to several carbon atoms and the corresponding number of hydrogens could be an alcohol with an -OH group, or an ether with a C-O-C group. Positional isomers have a given functional group in different locations (e.g., 1-pentanol vs. 2-pentanol).
Structural proteins basics
Structural proteins are fibrous proteins that have an elongated shape and provide structural support for cells and organ tissues. The first type of fibrous proteins are keratins, which form the skin, hair, and nails. Keratins are classified as soft or hard according to their sulfur content (i.e. the relative number of cysteine residues in their polypeptide chains). The low-sulfur keratins of the skin are much more flexible than the high-S, hard keratins.
Structural strain theory
Structural strain theory traces the origins of deviance to the tensions that are caused by the gap between societal goals and the means people have available to achieve said goals. The related concept of anomie describes social instability caused by the breakdown of social bonds, such as social norms, between individuals and communities.
Types of hormones??
Structurally, hormones can be divided into peptide, steroid, and amino acid-derived hormones. Steroid hormones are derived from cholesterol and are lipid-soluble. They diffuse through the plasma membrane and influence gene transcription. Thus, their effects tend to be slow-onset and long-lasting. They can affect sex (estrogen, testosterone, progesterone), salt (aldosterone, a mineralocorticoid), and sugar (cortisol, a glucocorticoid). Amino acid-derived hormones include T3/T4 and (nor)epinephrine. All other high-yield hormones are peptides. Peptide hormones are larger polar molecules that cannot enter cells directly. Therefore, they bind with membrane receptors and trigger secondary messaging cascades, exerting relatively rapid-onset and shorter-lasting effects.
Suicide inhibitor
Suicide inhibition occurs when an enzyme binds the inhibitor (structurally a substrate analogue) and forms an irreversible complex with it, usually through a covalent bond. This can involve the inhibitor being chemically modified by the enzyme during the normal course of catalysis to produce a reactive group that is specifically responsible for the formation of the irreversible inhibitor-enzyme complex.
Sulfhydryl groups
Sulfhydryl groups, and the cysteine side chain contains a sulfhydryl group
Adapting Coping
Support-seeking is the only adaptive coping response and the findings indicate that respondents were less likely to report maladaptive coping with stressful situations and thus more likely to report adaptive coping strategies.
Basal ganglia
The basal ganglia are located just under the cortex and connect to both the brainstem and the cortical lobes. The basal ganglia are involved in several functions, including voluntary movement, habitual behaviors, learning, and emotion.
What is surfactants?
Surfactants are amphipathic molecules (containing both hydrophilic and hydrophobic regions) that reduce the surface tension of a liquid. For the MCAT (and in your body), the most important example is pulmonary surfactant, which reduces the surface tension in the alveoli, allowing them to remain inflated when the lung is compressed during respiration.
Symbolic interactionism
Symbolic interactionism examines small scale (or micro level) social interactions, focusing attention on how shared meaning is established among individuals or small groups. Clinical encounters involving patient-provider communication are consistent with the analysis of social interaction at the micro level. In addition, the study of rapport, empathy, and disagreements involves the interpretation of meaning among social actors.
Main Sociological Theories
Symbolic interactionism focuses on the symbolic meaning that people develop and rely upon in the process of social interactions. Smoking is an excellent example, because the social symbolism of smoking is a point of contention across social groups. In previous years—and to some extent in certain social circles now—smoking was seen as trendy, whereas in others it may be seen negatively as a symbol of poor self-regard and ignorance. Conflict theory instead emphasizes the role of coercion and power in producing social order. It sees society as fragmented into groups that compete for social and economic resources. Social order is maintained by those with the most power, usually those with the greatest political, economic, and social capital. Finally, functionalism views society as a system of interconnected parts that carry out a specific role that enables them to cooperate to maintain social equilibrium for society as a whole. An important point is that these perspectives do not contradict each other; instead, the MCAT tends to ask which theoretical approach is exemplified by a given statement
Synapses
Synapses are small structures at the end of the axon of a neuron that allow the neuron to communicate with another nerve, a muscle cell, or a gland. Neurotransmitters are stored in vesicles in the axon terminal. When the action potential arrives, voltage-gated calcium channels are triggered, allowing Ca2+ to rush into the axon terminal. These calcium ions serve as the signal for the cell to use exocytosis to push the neurotransmitters into the synaptic cleft—the space that exists between the axon and the post-synaptic membrane. The space of the cleft is exceptionally small, such that simple diffusion is enough to very quickly carry the neurotransmitters across the cleft to the post-synaptic membrane. There, the neurotransmitters can act as ligands binding to their receptors. Neurotransmitters must be cleared out of the synaptic cleft quickly. This allows the body to tightly regulate the strength and timing of the signals sent by nerves. Neurotransmitters can either be broken down by enzymes in the cleft (the classic example being acetylcholinesterase, which breaks down acetylcholine) or taken back up by the presynaptic axon for re-use later.
T-cell activation requires ________.
T cells are acitavted by antigen-presenting cells, including B cells, macrophages, and dendritic cells. These cells display antigens on MHC molecules on the membrane.
How T-cells work??
T cells recognize cells that were originally self, but have been damaged by viral infections or have malfunctioned in ways likely to turn them into cancer cells. Then, various subgroups of T cells either directly attack compromised/foreign cells or mobilize responses to them based on antigen fragments that are presented by major histocompatibility complex (MHC) class I and II.
Material Culture
Tangible, physical items produced and used by members of a specific culture group and reflective of their traditions, lifestyles, and technologies
Gestalt law of similarity
The Gestalt law of similarity suggests that we tend to group similar items together in order to see them as forming a Gestalt (or whole) within a larger form. Therefore, instead of perceiving six rows consisting of dashes and zeros in Figure 1, we are more likely to group the similar zeros together in order to perceive a line of zeros among a field of dashes
PPP and NADPH
The PPP regenerates the universal reducing agent for anabolic pathways, NADPH, from NADP+ and H+. NADPH is critical for preventing cellular damage from free radicals derived from oxygen. G6PD is inhibited by high levels of NADPH. Hormonal regulation also impacts the transcription of the G6PD gene.
Telomere
Telomeres are repeating DNA sequences found at the ends of chromosomes. They vary widely in length, with some exceeding 10,000 base pairs. Telomeres serve to prevent chromosomal damage; more specifically, they prevent chromosomes from losing coding base pair sequences at their termini. Telomeres also act like the plastic tips on the ends of shoelaces in that they prevent individual chromosomes from fusing to each other end-to-end. Telomere activity is controlled by the mechanisms of erosion and addition.
Tetrahedral molecules
Tetrahedral molecules contain four electron-rich areas and four bonded atoms, at angles of 109.5°. Methane (CH4) is a classic example of tetrahedral geometry. Trigonal pyramidal molecules likewise have four electron-rich areas, but only three are bonded atoms and the fourth is a lone pair. Ammonia (NH3) is a prototypical example of this geometry. Bent molecules, like H2O, have two bonded atoms and two lone pairs. The bond angles in trigonal pyramidal molecules and bent molecules (107° and 104.5°, respectively) are slightly smaller than the 109.5° angle found in tetrahedral molecules.
Me and I
The "me" is the collection of attitudes taken from society, whereas the "I" is the autonomous sense of self that reacts to the "me."
DNA helix and transcription
The DNA helix must be unzipped for transcription to take place, which means that some of the same machinery used for DNA replication has to be engaged, especially enzymes like helicase and topoisomerase. RNA polymerase is the enzyme responsible for RNA synthesis. In eukaryotes, it binds to a promoter region upstream of the start codon with the assistance of transcription factors, the most important of which is the TATA box. RNA polymerase travels along the template strand in the 3'-5' direction, synthesizing an antiparallel complement in the 5'-3' direction. The template strand is known as the antisense strand, and the opposite strand is known as the sense strand, because it corresponds to the codons on the mRNA that is eventually exported to the cytosol for translation.
absolute vs relative refractory period
The absolute refractory period lasts nearly the entire duration of an action potential, during which time a second action potential cannot be generated. During this time, voltage-gated sodium channels are "inactivated." If this term is not familiar, note that voltage-gated sodium channels have two gates that must be open for sodium to flow inward and depolarize the cell membrane. If the "inactivation gate" is closed, the channels are inactivated. If the inactivation gate is open but the activation gate is closed, the channel is "de-inactivated" — it isn't inactivated, but it is not yet open either.
Adaptive immune system
The adaptive immune system includes B cells and T cells, both of which are lymphocytes that are produced in the bone marrow and mature in the lymphatic system. B cells recognize antigens and secrete large amounts of antibodies in response. The human body utilizes five classes of antibodies: immunoglobulin (Ig) A, IgD, IgE, IgG, and IgM, which differ in the details of their heavy chains. This response is known as humoral immunity. In contrast, T cells correspond to the cell-mediated branch of the adaptive immune system. T cells recognize cells that were originally self, but have been damaged by viral infections or have malfunctioned in ways likely to turn them into cancer cells. Then, various subgroups of T cells either directly attack compromised/foreign cells or mobilize responses to them based on antigen fragments that are presented by major histocompatibility complex (MHC) class I and II.
The adaptive immune system (B and T cells)
The adaptive immune system includes B cells and T cells, both of which are lymphocytes that are produced in the bone marrow and mature in the lymphatic system. B cells recognize antigens and secrete large amounts of antibodies in response. The human body utilizes five classes of antibodies: immunoglobulin (Ig) A, IgD, IgE, IgG, and IgM, which differ in the details of their heavy chains. This response is known as humoral immunity. In contrast, T cells correspond to the cell-mediated branch of the adaptive immune system. T cells, which mature in the thymus, recognize cells that were originally self, but have been damaged by viral infections or have malfunctioned in ways likely to turn them into cancer cells. Then, various subgroups of T cells either directly attack compromised/foreign cells or mobilize responses to them based on antigen fragments that are presented by major histocompatibility complex (MHC) class I and II.
Sulfide bonds
The amino acid that forms sulfide bonds is cysteine, which has a thiol (-SH) group in its side chain. Disulfide bonds arise when one cysteine's sulfur atom connects to another, losing the attached hydrogen atoms in the process. These bonds are a key part of protein tertiary structure.
Residual Volume
The amount of air that must remain in the lung at all times in order to prevent collapse
Normality and Equivalence point
The amount of base (or acid) required to fully neutralize an acid (or base) is given by the equation NacidVacid = NbaseVbase, which relates the normalities and volumes of the two solutions. For monoprotic species, where normality and molarity are equal, this simplifies to the fundamental concept of "moles acid = moles base," while for polyprotic species, it can be described as "moles H+ = moles OH−." In a titration, complete neutralization occurs at a position termed the equivalence point. The above equation, then, is only valid at the equivalence point, not at any random point over the course of the titration.
Ionization energy
The amount of energy required to completely remove one valence electron from an isolated atom in the gaseous state is defined as the ionization energy. The periodic table trend for ionization energy increases as one move up and to the right. N and O are the exception to these trends, however, due to electron repulsion from oxygen's additional electron in the already half-filled 2p orbital.
Kd and Ka
The association constant (Ka) can also be defined, using the mathematical formalism of equilibrium constants, as [ES]/[E][S], where [ES] is the concentration of the enzyme-substrate complex, [E] is the concentration of the enzyme, and [S] is the concentration of the substrate. The dissociation constant (Kd) is then the inverse of Ka, and can be defined as [E][S]/[ES].
Action of AV node
The atrioventricular (AV) node allows the action potential to pass through to the ventricles after the atria have contracted. At this point, the ventricles must contract to push the blood out of the heart. Since the ventricles are larger than the atria, it is a bit more difficult to get them to contract together, so the signal is sped through the bundle of His and Purkinje fibers to all the muscle cells of the ventricles.
Azimuthal quantum number (angular momentum)
The azimuthal, or angular momentum, quantum number (l) describes the subshell of the principal quantum number in which the electron is found, with values ranging from 0 to n − 1, where l = 0 is the s subshell, l = 1 is the p subshell, l = 2 is the d subshell, and l = 3 is the f subshell.
Steps of beta-oxidation
The basic logic of beta-oxidation is to chop up extended fatty acid chains into two-carbon units of acetyl-CoA. Step 1 of beta-oxidation involves forming a C=C double bond between the alpha and beta carbons of the carbonyl group at the head of the acyl-CoA molecule. This is coupled to the formation of FADH2. Then, in step 2, an -OH group is added to the beta carbon. The C-OH bond on the beta carbon is oxidized to C=O in step 3, and NADH is formed. Then, in step 4, the molecule is broken up, yielding an acetyl-CoA group and a shorter acyl-CoA group. This process is easiest to visualize with a saturated fatty acid with an even number of carbons, but special enzymes exist to handle unsaturated fatty acid and odd numbers of carbons.
Hemoglobin and oxygen saturation
The binding affinity between hemoglobin and oxygen is often displayed in graphical form. A hemoglobin-oxygen binding curve typically includes hemoglobin's percent saturation with oxygen on the y-axis and the partial pressure of oxygen on the x-axis. The higher the partial pressure of oxygen, the higher the oxygen saturation tends to be. Interestingly, under certain conditions, the binding curve can shift toward the right along the x-axis; this decreases the hemoglobin-oxygen binding affinity, allowing oxygen to be more easily dropped off in the tissues. These conditions include low (acidic) plasma pH and increased levels of carbon dioxide - both of which can indicate a shortage of oxygen. This rightward shift of the hemoglobin-oxygen binding curve is termed the Bohr effect. A compound known as 2,3-bisphosphoglyceric acid (2,3-BPG) can enhance these effects, further promoting the release of oxygen from hemoglobin.
Thermoregulation
The body must maintain homeostasis of many parameters, including osmolality, pH, energy, and temperature. The maintenance of body temperature is known as thermoregulation. This process relies on multiple systems within the human body, including the endocrine, cardiovascular, integumentary, and respiratory systems. The anterior hypothalamus serves as the body's "thermostat" to maintain body core temperature. Heat exchange is determined by convection, conduction, evaporation, and radiation. Radiation, conduction, and convection are determined by the difference between the skin temperature and the ambient temperature. The rate of heat body heat loss depends primarily on the surface temperature of the skin, which is in turn a function of cutaneous blood flow. The body can lose heat by increasing cutaneous blood flow and sweating, or by decreasing the basal metabolic rate through thyroid signaling. It can gain heat by decreasing cutaneous blood flow, increasing muscular activity (through movement and shivering), increasing the basal metabolic rate through thyroid signaling, metabolizing brown adipose (in infants only), or triggering piloerection of the hair on the body (goosebumps). A forced change in body temperature results when an environmental stress is sufficient to overcome the thermoregulatory systems of the body. For example, prolonged time in cold water results in forced hypothermia, while prolonged time in hot water results in hyperthermia. A regulated change in body temperature occurs when the hypothalamic "temperature setting" is shifted, as when a fever results from infection by a pathogen.
Parallel processing info
The brain must process input in order to create perceptions. In particular, the brain is able to create a cohesive image of the world through parallel processing, which refers the ability to analyze and combine several pieces of information regarding color, motion, and shape at once. Through this process, the new information that is received through the visual pathways can be compared with memories. In this way, the brain can rapidly come to the conclusion that, for example, not only are you looking at a dog, but it is your dog that you've had for years.
The brainstem
The brainstem consists of the midbrain, pons, and medulla oblongata, and provides the connection from the brain to the spinal cord. It regulates crucial functions basic to the survival of the organism, such as heart rate, respiration, sleep, and overall activation of the rest of the CNS. The cerebellum, found just underneath the occipital lobe, serves to direct complex coordinated movement, such as walking or playing the piano. The basal ganglia are located just under the cortex and connect to both the brainstem and the cortical lobes. The basal ganglia are involved in several functions, including voluntary movement, habitual behaviors, learning, and emotion.
What is the brainstem responsible for?
The brainstem consists of the midbrain, pons, and medulla oblongata, and provides the connection from the brain to the spinal cord. It regulates crucial functions basic to the survival of the organism, such as heart rate, respiration, sleep, and overall activation of the rest of the CNS. The cerebellum, found just underneath the occipital lobe, serves to direct complex coordinated movement, such as walking or playing the piano. The basal ganglia are located just under the cortex and connect to both the brainstem and the cortical lobes. The basal ganglia are involved in several functions, including voluntary movement, habitual behaviors, learning, and emotion.
Surfactant
The bronchi divide into secondary bronchi, tertiary bronchi, and bronchioles, ending in alveoli, where gas exchange takes place. Alveoli are sacs coated with surfactant, a film that reduces surface tension, allowing the alveoli to remain inflated when the lung is compressed during exhalation. Each alveolus is surrounded by tiny capillaries. An average pair of lungs contains something on the order of 600 million alveoli, resulting in a collectively tremendous surface area for gas exchange.
Capacitor and battery
The capacitor charges up and stores energy in the electric field between the places. The energy stored is ½CV2, where V is the voltage across the capacitor. The battery is the source of energy for the circuit and thus is a store of energy.
Things remain stable with aging
The capacity for retrieving general information (i.e., semantic memory, crystallized intelligence) is unaffected by aging.
Beta-oxidation of FA (c18 acids)
The carbon atom is c1 of the acid, this will end up in the acetyl conzyme A. The sulfur will end up c16 atoms
The dependency ratio
The dependency ratio is a ratio of the number of economically dependent members of the population to the number of economically productive members. The economically dependent are those considered too young or too old to work, whereas the economically productive are the working-age population
The diathesis-stress model
The diathesis-stress model postulates that some people are born with genetic or biological traits that predispose them to depression. When they are in certain environments, these traits are activated and depression emerges.
Alcohol and aldehydes IR spectrum
The carbonyl stretching frequency falls in the range of 1700-1750 cm-1, while the O-H stretching frequency is expected to fall in the range of 3200-3500 cm-1. The reaction is thus complete when the signal in the 1700-1750 cm-1 range has completely disappeared. Infrared (IR) spectroscopy is a method used to identify specific functional groups present on an unknown molecule. Group frequencies are vibrations that are associated with certain functional groups. A molecule can be identified when its vibrational frequencies on an IR spectrum are compared to known spectra values. Unlike UV-Vis spectroscopy, which use larger energy absorbance from electronic transitions, IR spectroscopy relies on the much smaller energy absorbance that occurs between various vibrational and rotational states. Only molecules that undergo a net change in the dipole moment during vibrational and rotational motion can absorb IR radiation. Diatomic molecules (e.g. O2, N2, and Br2) do not return IR signals because no net change in the dipole moment occurs. Molecules respond to the influx of energy by either stretching or bending. Stretching is a result of changing distances in a bond between two atoms on the molecule. Bending is any change in the angle between two bonds on the molecule. The various types of vibrations and rotations absorb at different frequencies within the infrared region, resulting in unique spectral properties for different molecular species. The most high-yield IR spectra for the MCAT are those of carbonyl groups (C=O) and hydroxyl groups (OH). The figure below shows the IR spectra for these important functional groups.
Cell cycle division
The cell cycle can be divided into a resting phase (interphase) and cell division (mitosis or meiosis). Resting phase is also known as Gap 0 (G0). During this period, the cell just goes about its business; in fact, many fully-differentiated cells in the body remain in G0 for long periods of time. Because it can last for an essentially indefinite period of time, resting phase is often considered not to be a proper part of the cell cycle itself.
G0 phase
The cell cycle can be divided into a resting phase (interphase) and cell division (mitosis or meiosis). Resting phase is also known as Gap 0 (G0). During this period, the cell just goes about its business; in fact, many fully-differentiated cells in the body remain in G0 for long periods of time. Because it can last for an essentially indefinite period of time, resting phase is often considered not to be a proper part of the cell cycle itself.
Central dogma
The central dogma of molecular biology states that information is passed from DNA to RNA to protein. This means that when a cell needs more of a certain protein, it can increase the degree to which the gene corresponding to that protein is transcribed. Transcribing more or less of a gene in response to the cell's needs is known as gene expression. It plays a major role in the differentiation of organs in multicellular organisms, and can also vary on shorter time scales in response to changing environmental conditions. The details of how gene expression is regulated in eukaryotes are quite intricate, but you should be aware of some key concepts for the MCAT.
Cerebral cortex and lobes
The cerebral cortices overlay the rest of the brain's structures and are responsible for many of the higher functions seen in humans. The cortices can be divided into four lobes: frontal, parietal, occipital, and temporal. The frontal lobe is associated with making judgments and regulating behavior as a part of executive functioning. The occipital lobe is most closely related to visual processing, as data from the optic nerves are sent directly there. The parietal lobe is associated with integrating various sensory input, and both the parietal and temporal lobes are important for language.
Charge of a polypeptide
The charge of a peptide at a given pH can be roughly predicted based on how many acidic and basic residues they contain. The side chains of the acidic amino acids, aspartic acid and glutamic acid, will be protonated and uncharged (-COOH) below a pH of roughly 3 and deprotonated and negatively-charged (-COO-) above that pH. Correspondingly, the side chains of the basic amino acids (histidine, lysine, and arginine) will be protonated and positively-charged at pH levels below the pKa values of their side chains (roughly 6.0, 10.5, and 12.5, respectively).
How to calculate charge of a peptide?
The charge of a peptide at a given pH can be roughly predicted based on how many acidic and basic residues they contain. The side chains of the acidic amino acids, aspartic acid and glutamic acid, will be protonated and uncharged (-COOH) below a pH of roughly 3 and deprotonated and negatively-charged (-COO-) above that pH. Correspondingly, the side chains of the basic amino acids (histidine, lysine, and arginine) will be protonated and positively-charged at pH levels below the pKa values of their side chains (roughly 6.0, 10.5, and 12.5, respectively).
The charge of a peptide
The charge of a peptide at a given pH can be roughly predicted based on how many acidic and basic residues they contain. The side chains of the acidic amino acids, aspartic acid and glutamic acid, will be protonated and uncharged (-COOH) below a pH of roughly 3 and deprotonated and negatively-charged (-COO-) above that pH. Correspondingly, the side chains of the basic amino acids (histidine, lysine, and arginine) will be protonated and positively-charged at pH levels below the pKa values of their side chains (roughly 6.0, 10.5, and 12.5, respectively).
Vital Capacity (VC)
The difference between the minimum and maximum volume of air in the lungs (TLC-RV). It is equal to inspiratory reserve, expiratory reserve, and Tidal volume
pH and amino acids at physiological pH
The charge pattern of amino acids changes in response to the surrounding pH. Let's consider a simple amino acid, alanine, which has a neutral side chain. At an extremely low pH, both the carboxylic acid group and the amine group will be protonated (-COOH and -NH3+, respectively), resulting in a net charge for the amino acid of +1. At an extremely high pH, very few H+ ions will be available, and both groups will be deprotonated (-COO− and -NH2), resulting in a net charge of −1. To understand what happens at an intermediate pH, consider the relevant functional groups. Carboxylic acids are weak acids, whereas amine groups are weakly basic. This means that -COOH groups are relatively "happy" to give up their extra proton and exist as carboxylate ions (-COO−), even at relatively low pH values where there is a fair amount of H+ present. In other words, a huge amount of H+ must be present to force the carboxylate ions to accept a proton. In contrast, amine groups "like" being protonated, which means that the pH must be quite high for it to be willing to give up its proton. Thus, for intermediate pH ranges, the carboxylic acid will be deprotonated (-COO−) and the amine group will be protonated (NH3+), resulting in a net charge of zero. This is the case at physiological pH.
coefficient of determination (r^2)
The coefficient of determination (r2) indicates how much variation in one variable is explained by variation in the other. Remember to round aggressively on the MCAT, as 95% of MCAT calculations will allow you to do so. If, by rare chance, your answer is close to two answer choices, you can go back and calculate more carefully. However, this is so rarely necessary that you can save significant time by rounding and estimating aggressively. In this case, round 0.75 to 0.7 and recognize that since 72 is 49, 0.72 is 0.49.
cAMP and G protein
The common cAMP-mediated G-protein signaling pathway is activated by the binding of a hormone to a receptor on the cell membrane. Binding of the hormone activates a G protein that is associated with the receptor. The G protein migrates through the membrane to activate another membrane protein, adenylate cyclase. Adenlyate cyclase converts ATP to cAMP, which is called the second messenger. cAMP activates protein kinases and thereby alters cell metabolism.
Demand Characteristics (Hawthorne Effect)
The concept of demand characteristics refers to the phenomenon by which study participants pick up on subtle or overt clues about the purpose of the study, the hypothesis, or the expectations of the experimenters, and alter their behavior as a result. Behavior can be altered in a positive or negative way, meaning subjects may behave in a way that seeks to please the experimenters and support their hypothesis, or in a negative way
Hardy-Weinberg equilibrium
The concept of is often used to model stable gene pools that satisfy the following assumptions: (1) organisms must be diploid and reproduce sexually; (2) mating is random; (3) the population size is very large; (4) alleles are randomly distributed by sex; (5) no mutations occur; and (6) there is no migration into or out of the population. The Hardy-Weinberg equations allow us to use allele frequencies to predict the distribution of phenotypes in the population and vice versa. If p and q are the only two alleles of a gene present in the population, then p + q = 1. Squaring the equation yields: (p + q)2 = 12 → p2 + 2pq + q2 = 1. This second equation allows us to connect genotypes and phenotypes, because the p2 and q2 terms correspond to individuals homozygous for p and q, respectively, while the 2pq term gives the frequency of heterozygotes. Other mechanisms are associated with changes in the gene pool of a species, such as genetic drift and bottlenecks. Genetic drift refers to the role of chance, in the absence of strong selective pressures, in determining the reproductive fitness of various alleles. When no strong pressure exists for a certain allele, it may randomly happen to be reproduced more or less often. These random effects can add up over the course of evolution. A related, but more specific, concept is that of an evolutionary bottleneck. Bottlenecks occur when some external event dramatically reduces the size of a population in a way that is essentially random with regard to most, if not all, alleles. This dramatically reduces diversity in the gene pool.
The conditioned stimulus
The conditioned stimulus is a stimulus that, only after being paired several times with an unconditioned stimulus triggers a conditioned response
Diaphragmatic breathing
The contraction of the diaphragm muscle changes the shape of the muscle from concave-up to approximately flat. This increases the volume of the lungs, decreasing the pressure inside the lungs according to this inverse relationship. Air then diffuses into the lungs down its pressure gradient until the pressure inside the lungs is equal to atmospheric pressure.
Location/PDH
The conversion of pyruvate to acetyl-CoA is accompanied by the production of 1 molecule of NADH, which can eventually enter the electron transport chain to generate ATP, and 1 molecule of carbon dioxide. In eukaryotes, the pyruvate dehydrogenase complex is located within the mitochondrial matrix.
Why continuous reinforcement is best for the beginning of the acquisition phase of operant conditioning?
The correct response must be unambiguously made known to the subject, generally through a shaping procedure. Thereafter, if every correct response is reinforced, other (incorrect) responses are infrequent and the behavior gains strength and learning results.
Sound speed and medium
The densities of solids are the greatest because of the strong intermolecular forces, which create lattice structures with closely bonded molecules. While solids tend to be densest, they also tend to be the least compressible, which corresponds to a high bulk's modulus. As a result, the B/ρ quotient is the highest for solids, followed by liquids, and then gases.
Prokaryote vs. Eukaryote cells
The division between prokaryotes and eukaryotes (which include both single-celled organisms such as yeast and multicellular organisms such as ourselves) is arguably the most basic fork in the tree of life. Prokaryotes (including bacteria and Archaea) are defined by the absence of a nucleus and membrane-bound organelles. Bacteria are ubiquitous and play a major role in the maintenance of human health. Most bacteria in the human body are harmless or beneficial, but some are pathogens. Although bacteria do have specific genus and species names, they are commonly described in terms of their shape. Spherical bacteria are known as cocci, rod-shaped bacteria are called bacilli, and spiral-shaped bacteria are known as spirilli. Bacteria are also classified in terms of how they use oxygen in metabolism. Bacteria that do not require oxygen for metabolism are known as anaerobes. For obligate anaerobes, oxygen is toxic. Aerotolerant anaerobes are similar to obligate anaerobes in that they cannot engage in aerobic metabolism, but oxygen is not toxic for them. Facultative anaerobes can engage in either aerobic or anaerobic metabolism, depending on the circumstances. Bacteria that require oxygen for metabolism are known as obligate aerobes. Since bacteria by definition do not have membrane-bound organelles, their structure is simpler than that of eukaryotes. However, they have some key structures, including a cell wall containing peptidoglycan that encloses the cell membrane, ribosomes that are differently sized from those of eukaryotes (30S and 50S subunits, instead of the 40S and 60S components in eukaryotes), rotating flagella, and a single circular chromosome. Structural differences between eukaryotes and prokaryotes are often specifically targeted by antibiotics.
The drive reduction theory
The drive reduction theory is focuses only on internal factors like hunger, thirst, and sex drive
Germ layers
The ectoderm gives rise to the epidermis, hair, nails, and the epithelia of the nose, mouth, and lower anal canal, as well as the lens of the eye, nervous system, and inner ear. The mesoderm develops into multiple systems, including the musculoskeletal system, circulatory system, and the majority of the excretory system. In addition, it gives rise to the gonads, muscular and connective tissue layers of the digestive and respiratory systems, and the adrenal cortex. The endoderm forms the epithelial linings of the digestive and respiratory tracts, as well as the pancreas, thyroid, bladder, distal urinary tracts, and parts of the liver.
Mutations and evolution
The effects of most point mutations can be expected to be negative, but occasionally mutations result in more functional proteins. This is a major driver of evolution. Additionally, it is important to differentiate between somatic and germline mutations. Germline mutations take place in eggs and sperm (or their progenitor cells), and therefore are passed down to other generations. Somatic mutations take place in other body cells and are not passed down to other generations.
Complex of ETC
The electron transport chain (ETC) uses free oxygen as the final electron acceptor of the electrons removed from NADH and FADH2 formed in glycolysis and the Krebs cycle (also known as the citric acid cycle). The ETC is composed of four large protein complexes (Complexes I-IV) embedded in the inner mitochondrial membrane and two small electron carriers shuttling electrons between them. Complex I is known as NADH dehydrogenase, II is known as succinate dehydrogenase, III is known as cytochrome bc or c, and IV is known as cytochrome c oxidase. Electrons are released from NADH and FADH2 through a series of reactions.
Components of ETC
The electron transport chain (ETC) uses free oxygen as the final electron acceptor of the electrons removed from NADH and FADH2 formed in glycolysis and the Krebs cycle (also known as the citric acid cycle). The ETC is composed of four large protein complexes (Complexes I-IV) embedded in the inner mitochondrial membrane and two small electron carriers shuttling electrons between them. Complex I is known as NADH dehydrogenase, II is known as succinate dehydrogenase, III is known as cytochrome bc or c, and IV is known as cytochrome c oxidase. Electrons are released from NADH and FADH2 through a series of reactions.
The electron transport chain
The electron transport chain (ETC) uses free oxygen as the final electron acceptor of the electrons removed from NADH and FADH2 formed in glycolysis and the Krebs cycle (also known as the citric acid cycle). The ETC is composed of four large protein complexes (Complexes I-IV) embedded in the inner mitochondrial membrane and two small electron carriers shuttling electrons between them. Complex I is known as NADH dehydrogenase, II is known as succinate dehydrogenase, III is known as cytochrome bc or c, and IV is known as cytochrome c oxidase. Electrons are released from NADH and FADH2 through a series of reactions.
The electron transport chain (ETC)
The electron transport chain (ETC) uses free oxygen as the final electron acceptor of the electrons removed from NADH and FADH2 formed in glycolysis and the Krebs cycle (also known as the citric acid cycle). The ETC is composed of four large protein complexes (Complexes I-IV) embedded in the inner mitochondrial membrane and two small electron carriers shuttling electrons between them. Complex I is known as NADH dehydrogenase, II is known as succinate dehydrogenase, III is known as cytochrome bc or c, and IV is known as cytochrome c oxidase. Electrons are released from NADH and FADH2 through a series of reactions.
Why arginine a better base than lysine?
The electron-donating groups around the basic nitrogen on arginine make its conjugate acid more stable.
Hess's Law
The enthalpy (H) of a reaction is the heat energy it contains. The most important law when looking at enthalpy is Hess's law: ΔHrxn = Σ∆Hproducts - ΣΔHreactants. This equation illustrates that enthalpy, like entropy, is a state function. This means that the ∆H accompanying a chemical reaction is independent of the mechanism by which the reaction occurs.
Keratin basic
The first type of fibrous proteins are keratins, which form the skin, hair, and nails. Keratins are classified as soft or hard according to their sulfur content (i.e. the relative number of cysteine residues in their polypeptide chains). The low-sulfur keratins of the skin are much more flexible than the high-S, hard keratins.
The fluid mosaic model
The fluid mosaic model states that cellular membranes consist of a lipid bilayer populated by peripheral and integral membrane proteins. A chloride channel will allow chloride ions to pass from one side of the membrane to the other, so it must be a transmembrane integral protein. .
Focal length
The focal length of the mirror depends only on the radius of the curvature.
Oxidation and reduction
The following features are associated with reduction in organic chemistry: (1) gain of an electron, (2) decreased oxidation state, (3) formation of a C-H bond (e.g. alkene → alkane), and (4) loss of a C-O or C-N bond (or any bond between carbon and an electronegative atom). Conversely, oxidation is associated with (1) loss of an electron, (2) increased oxidation state, (3) loss of a C-H bond (e.g. alkane → alkene), and (4) gain of a C-O or C-N bond (or any bond between carbon and a highly electronegative atom).
Oxidation and Reduction
The following features are associated with reduction in organic chemistry: (1) gain of an electron, (2) decreased oxidation state, (3) formation of a C-H bond (e.g. alkene → alkane), and (4) loss of a C-O or C-N bond (or any bond between carbon and an electronegative atom). Conversely, oxidation is associated with (1) loss of an electron, (2) increased oxidation state, (3) loss of a C-H bond (e.g. alkane → alkene), and (4) gain of a C-O or C-N bond (or any bond between carbon and a highly electronegative atom). Oxygen-containing organic compounds exist on a spectrum of oxidation from alcohols (most reduced/least oxidized) to aldehydes/ketones (intermediate reduction/oxidation) to carboxylic acids (least reduced/most oxidized). A primary alcohol can be oxidized to an aldehyde by a mild oxidizing agent (such as PCC) or to a carboxylic acid by a strong oxidizing agent like NaCr2O7. A secondary alcohol will be oxidized to a ketone by either a mild or a strong oxidizing agent. A strong oxidizing agent will likewise oxidize an aldehyde to a carboxylic acid. A strong reducing agent, such as LiAlH4, can reduce a carboxylic acid directly to an alcohol, while weak reducing agents such as NaBH4 will not reduce carboxylic acids at all. A special agent, DIBAL, can reduce a carboxylic acid to an aldehyde when applied at a precise 1:1 ratio. Both mild and strong reducing agents can reduce aldehydes and ketones to primary and secondary alcohols, respectively.
Glycosidic bond acetal
The formation of a glycosidic bond transforms the hemiacetal or hemiketal found at the anomeric carbon into an acetal or a ketal, because the -OH group that is characteristic of a hemiacetal or hemiketal is transformed into a second -OR group, which defines an acetal/ketal.
Hemiacetal and acetal
The formation of a glycosidic bond transforms the hemiacetal or hemiketal found at the anomeric carbon into an acetal or a ketal, because the -OH group that is characteristic of a hemiacetal/hemiketal is transformed into a second -OR group, which defines an acetal/ketal.
Fourth level of protein structure
The fourth level of protein structure, which is not present in all proteins, is quaternary structure. Quaternary structure exists when a single protein consists of two or more polypeptide chains (called subunits). For example, hemoglobin is made up of four identical heme subunits joined together. The number of subunits will be reflected in the name given to its structure (dimer, trimer, pentamer). If the subunits are identical, the prefix "homo" is used, and if they differ, the term "hetero" is used. Thus, a protein with two identical subunits would be a homodimer, while a heterotetramer would be a protein with four subunits, at least some of which are different. These subunits can interact with each other, contribute to an active site or to the dynamics of the complex, or interact with some target molecules. The most common way the MCAT hints at the quaternary structure of a protein is to show that disulfide bond cleavage splits the protein into two or more pieces on a gel.
Fovea
The fovea is directly involved in color sensation and its distribution of receptors varies across different species.
Fundamental attribution error
The fundamental attribution error concerns the process of assigning causes to others' behaviors. When we observe someone else acting, this error leads us to overemphasize internal factors (e.g., attitudes, skill levels, or personal motives), as opposed to external ones (e.g., environmental factors or social considerations).
The fundamental attribution biases
The fundamental attribution error refers to the tendency to place less importance on the import of a situation or context on behavior, and instead place undue emphasis on dispositional or internal qualities in order to explain behavior. In other words, we have a tendency to think that people are how they act
The fundamental cause theory
The fundamental cause theory suggests that despite efforts to improve access to health care for low SES groups, new barriers emerge as a countervailing force against efforts to effect change
Functional unit of muscle
The fundamental unit of contraction is the sarcomere, which is defined as consisting of a band of thick myosin fibers and half of each of the two adjacent bands of thin fibers. Sarcomeres are divided into the I-band, A-band, H-zone, Z-line, and M-line. The M-line defines the middle of the sarcomere, running through the middle of the thick filaments, while the Z-lines define the edges, running through the middle of the thin filaments. The I-band refers to the region where only thin actin filaments are present, and the A-band is everything else, that is, the entire region where thick filaments are present, including areas of overlap with the thin filaments. The H-zone refers to the region where only thick filaments are present, making it analogous to the I-band. During contraction, the M-lines and Z-lines come closer together, the A-band stays the same, and the I-band and H-zone become shorter.
Sarcomere
The fundamental unit of contraction is the sarcomere, which is defined as consisting of a band of thick myosin fibers and half of each of the two adjacent bands of thin fibers. Sarcomeres are divided into the I-band, A-band, H-zone, Z-line, and M-line. The M-line defines the middle of the sarcomere, running through the middle of the thick filaments, while the Z-lines define the edges, running through the middle of the thin filaments. The I-band refers to the region where only thin actin filaments are present, and the A-band is everything else, that is, the entire region where thick filaments are present, including areas of overlap with the thin filaments. The H-zone refers to the region where only thick filaments are present, making it analogous to the I-band. During contraction, the M-lines and Z-lines come closer together, the A-band stays the same, and the I-band and H-zone become shorter.
Gate theory of pain
The gate control theory of pain asserts that non-painful input closes the "gates" to painful input, which prevents pain sensation from traveling to the central nervous system. Therefore, stimulation by non-noxious input is able to suppress pain.
The general adaptation syndrome (GAS)
The general adaptation syndrome (GAS) is a model of the body's stress response that consists of three stages: alarm, resistance, and exhaustion. An individual enters the stage of exhaustion only after that individual has encountered the stressor for a prolonged period of time. I
Oncogenes Vs. Tumor Suppressor Genes: alleles mutated in cancer
The genes involved in oncogenesis can be divided into two groups: oncogenes and tumor suppressor genes. The basic difference between them is that oncogenes function to promote abnormal growth and proliferation, leading to cancer, while tumor suppressor genes function to prevent tumorigenic properties. Oncogenes can arise from the mutation of other genes, termed proto-oncogenes. If not mutated, proto-oncogenes do not promote cancer, but certain mutations or inappropriately elevated gene expression can effectively turn them into oncogenes.
Haman genome
The human genome contains approximately 3 billion base pairs. To fit into human nuclei, which are generally about 6 μm (6 × 10−6 m) in size, DNA must be compressed. Subdividing the genome into linear chromosomes accomplishes some of this task, but the rest of the job is done by histones and chromatin.
ATP hydrolysis basics
The hydrolysis of ATP to ADP + inorganic phosphate (Pi) is extremely energetically favorable, so it is used to power other reactions. The phosphoanhydride bonds in ATP are considered high-energy because their hydrolysis releases a large amount of energy. This pattern is due to several features related to the structure of ATP. First, ADP and Pi, the products of the hydrolysis of a single ATP phosphoanhydride bond, have greater resonance stabilization than does ATP. Second, at physiological pH, the triphosphate unit of ATP carries four negative charges that are in close proximity to each other. This results in considerable repulsion, which can be minimized by hydrolysis. Hydrolysis is also entropically favorable. Finally, ADP and Pi are more stabilized by hydration than is ATP, because additional negatively charged groups are made available to interact with and bind water following hydrolysis.
Hydrolysis of ATP facts
The hydrolysis of ATP to ADP + inorganic phosphate (Pi) is extremely energetically favorable, so it is used to power other reactions. The phosphoanhydride bonds in ATP are considered high-energy because their hydrolysis releases a large amount of energy. This pattern is due to several features related to the structure of ATP. First, ADP and Pi, the products of the hydrolysis of a single ATP phosphoanhydride bond, have greater resonance stabilization than does ATP. Second, at physiological pH, the triphosphate unit of ATP carries four negative charges that are in close proximity to each other. This results in considerable repulsion, which can be minimized by hydrolysis. Hydrolysis is also entropically favorable. Finally, ADP and Pi are more stabilized by hydration than is ATP, because additional negatively charged groups are made available to interact with and bind water following hydrolysis.
Hypothalamus
The hypothalamus is responsible for shutting down the brain's arousal signals and causing the transition from wakefulness to sleep. Neurons in the ventrolateral preoptic nucleus (VLPO) connect directly to the brain's arousal-promoting centers, inhibiting their activity.
hRNA and poly A tail
The immediate product of transcription in eukaryotes is not mRNA, but heterogeneous nuclear RNA (hnRNA). hnRNA must undergo a set of post-transcriptional modifications to become mRNA. Examples commonly tested on the MCAT include the 3' poly-A tail, the 5' cap, and splicing. The 3' poly-A tail is a string of approximately 250 adenine (A) nucleotides added to the 3' end of an hnRNA transcript to protect the eventual mRNA transcript against rapid degradation in the cytosol. The 5' cap refers to a 7-methylguanylate triphosphate cap placed on the 5' end of an hnRNA transcript. Similarly to the 3' poly-A tail, it helps prevent the transcript from being degraded too quickly in the cytosol, but it also prepares the RNA complex for export from the nucleus
Post-transcriptional modifications
The immediate product of transcription in eukaryotes is not mRNA, but heterogeneous nuclear RNA (hnRNA). hnRNA must undergo a set of post-transcriptional modifications to become mRNA. Examples commonly tested on the MCAT include the 3' poly-A tail, the 5' cap, and splicing. The 3' poly-A tail is a string of approximately 250 adenine (A) nucleotides added to the 3' end of an hnRNA transcript to protect the eventual mRNA transcript against rapid degradation in the cytosol. The 5' cap refers to a 7-methylguanylate triphosphate cap placed on the 5' end of an hnRNA transcript. Similarly to the 3' poly-A tail, it helps prevent the transcript from being degraded too quickly in the cytosol, but it also prepares the RNA complex for export from the nucleus.
hnRNA
The immediate product of transcription in eukaryotes is not mRNA, but heterogeneous nuclear RNA (hnRNA). hnRNA must undergo a set of post-transcriptional modifications to become mRNA. Examples commonly tested on the MCAT include the 3' poly-A tail, the 5' cap, and splicing. The 3' poly-A tail is a string of approximately 250 adenine (A) nucleotides added to the 3' end of an hnRNA transcript to protect the eventual mRNA transcript against rapid degradation in the cytosol. The 5' cap refers to a 7-methylguanylate triphosphate cap placed on the 5' end of an hnRNA transcript. Similarly to the 3' poly-A tail, it helps prevent the transcript from being degraded too quickly in the cytosol, but it also prepares the RNA complex for export from the nucleus.
Baby Boomers (1946-1964)
The increasing share of the population over the age of 65 primarily stems from the baby boomers, the post-World War II generation in the United States and Canada. Birth rates were relatively high for almost two decades after World War II. Demographers define the baby boom generation as those individuals born between approximately 1946 and 1964. The baby boom generation is the main sociohistorical factor that explains the projection in the passage about the increasing share of the population over 65 years of age.
Intensity and loudness
The intensity of sound is a measure of the power delivered by sound over a given area, or as watts divided by meters squared. Intensity is not exactly the same as "loudness," because loudness has to do with how the intensity of sound is perceived. Intensity and loudness are closely related to amplitude, as intensity is proportional to the amplitude squared. Intensity is commonly measured in terms of decibels (dB). The decibel scale is a logarithmic scale expressing the intensity of a sound as its ratio to that of the smallest detectable sound intensity I0). The intensity ratio of sound in decibels is defined as dB = 10log(I/I0), where I0 is 1 × 10−12 W/m2.
Enzyme kinetic parameters
The kinetic parameters Vmax and Km are reported via Michaelis-Menten plots. However, Lineweaver-Burk plots may also be used. When the experimental data are examined in the form of double reciprocal Lineweaver-Burk plots, the x- and y-axes are 1/[S] and 1/V, respectively. Since these plots are a straight line, the slope of each line is Km/Vmax. The y-intercept on a Lineweaver-Burk plot represents 1/Vmax, while the x-intercept is −1/Km. These double-reciprocal plots are especially useful for distinguishing between competitive and noncompetitive inhibitors.
Lacteals
The lacteals (shown below) are structures in the intestines associated with absorbing fat into the lymphatic system.
The linguistic relativity hypothesis
The linguistic relativity hypothesis suggests that human cognition is affected by language.
Conjugated double bond
The longer the extended conjugated double bond system, the longer the wavelength of visible light that will be absorbed
Sarcomere and force
The longer the sarcomere initially, the larger the force
The looking-glass
The looking-glass self suggests that the self-concept is influenced by how we perceive that others are viewing us. Based on the looking-glass self, a person who acquires a stigmatized illness is likely to internalize the stigmatization directed against him or her.
The magnetic quantum number
The magnetic quantum number (ml) describes the spatial orientation of the orbital in question within its subshell. Potential values of ml range from −l to +l. Since each orbital can hold a maximum of two electrons, this means that an s subshell can contain up to two electrons, a p subshell can hold up to six electrons, a d subshell can contain up to 10, and an f subshell can hold up to 14.
Inspiration
The main mechanism of respiration is known as negative-pressure respiration. When the diaphragm (the muscle at the bottom of the thoracic cavity that separates it from the abdominal cavity below) contracts, the thoracic cavity expands. This causes the parietal pleura to expand, causing a pressure gradient that in turn causes the pulmonary pleura and the lungs to expand. When the lungs expand, the pressure within them decreases. The decreased pressure compared to the external environment causes air to rush into the respiratory tract
alveloi and gas-exchange
The main mechanism of respiration is known as negative-pressure respiration. When the diaphragm (the muscle at the bottom of the thoracic cavity that separates it from the abdominal cavity below) contracts, the thoracic cavity expands. This causes the parietal pleura to expand, causing a pressure gradient that in turn causes the pulmonary pleura and the lungs to expand. When the lungs expand, the pressure within them decreases. The decreased pressure compared to the external environment causes air to rush into the respiratory tract. Exhalation can be either passive or active. In passive exhalation, the simple relaxation of the diaphragm is enough to cause the lungs to contract, increasing the pressure and expelling air. However, the muscles between the ribs (internal intercostal muscles) and abdominal muscles can be used to force air out more intensely and quickly. This frequently occurs during exercise, but increased reliance on active exhalation even at rest can be a sign of respiratory disease. The final part of breathing is gas exchange. Blood runs through the alveolar capillaries and is separated by a wall only one cell thick from the air that is being breathed in. The deoxygenated blood being returned to the lungs is rich in carbon dioxide and poor in oxygen, while the air being breathed in is rich in oxygen and relatively poor in carbon dioxide. Therefore, oxygen and carbon dioxide can simply diffuse down their respective concentration gradients, although it is important to keep in mind that oxygen is carried by hemoglobin.
Controlling mechanism of blood pH
The major physiological mechanisms used to control blood pH include exhalation of carbon dioxide, conversion of carbon dioxide into bicarbonate in the blood, and the excretion of protons through the kidneys.
Structure and activity of fatty acids
The melting point of fatty acids increases as the length of the carbon tail increases. In addition, unsaturated fatty acids will have lower melting points than saturated fatty acids with the same number of carbon atoms. As a general rule, unsaturated fatty acids are liquids at room temperature while more saturated fats are solids. Fatty acids also demonstrate cis/trans isomerism. In cis fatty acids, the acyl groups are on the same side of the double bond, while in a trans fatty acid, the acyl groups are on opposite sides. Cis fats generally have higher boiling points, while trans fats have higher melting points.
Melting pot idea
The melting pot idea represents an image of an Americanized culture that is superior, and immigrants must "rise" to this level to be accepted by the core culture.
Structure of Mitocheondia
The mitochondria are separated from the rest of the cytoplasm by two membranes (an outer membrane and an inner membrane), both of which are composed of a phospholipid bilayer. The structure of mitochondria can therefore be subdivided into the outer membrane, the intermembrane space, the inner membrane, and the mitochondrial matrix, which is the innermost part of each mitochondrion. The mitochondrial matrix is the site of the citric acid cycle, and oxidative phosphorylation takes place via the action of protein complexes embedded in the inner membrane of the mitochondrion. As part of oxidative phosphorylation, the electron transport chain causes a buildup of protons in the intermembrane space, and the resulting proton gradient is used to power the activity of ATP synthase.
mitochondrial Genome
The mitochondrial genome is inherited from the mother of the offspring only. Mitochondria have their own transcription and translation machinery and replication of mitochondrial genome is independent of the nuclear genome.
Structural proteins
The most common function of proteins in the body is not enzymatic, but structural. Structural proteins are fibrous proteins that have an elongated shape and provide structural support for cells and organ tissues. The first type of fibrous proteins are keratins, which form the skin, hair, and nails. Keratins are classified as soft or hard according to their sulfur content (i.e. the relative number of cysteine residues in their polypeptide chains). The low-sulfur keratins of the skin are much more flexible than the high-S, hard keratins. The second type of fibrous proteins you must know are the actin and myosin proteins of muscle tissue. Actin and myosin interact to form cross-linkages that allow the sliding of the filaments over each other in muscle contraction, which takes place through the contraction and relaxation of the sarcomere, the fundamental unit of all muscle fibers. When muscle contracts, the actin and myosin filaments slide over each other and the H-zone (myosin-only region), Z-lines (sarcomere boundaries), and I-band (actin-only region) all shrink, while the A-band (the entire myosin region) remains the same size. The opposite occurs upon muscle relaxation. A third type of structural protein you should know for test day is collagen, which is found in tendons, forms connective ligaments within the body, and gives extra support to the skin. Collagen is a triple helix formed by three proteins that wrap around one another. Many collagen molecules are cross-linked together in the extracellular space to form collagen fibrils to provide structural support for the cell. Elastin polypeptide chains are cross-linked together to form flexible, elastic fibers that give stretched tissues flexibility and the ability to recoil spontaneously as soon as the stretching force is relaxed.
Innate Immunity
The non-cellular component of the innate immune system includes anatomical barriers and signaling molecules such as cytokines and complement proteins, while the cellular component includes a range of white blood cell types (leukocytes) that play various roles in responding to threats. White blood cells include neutrophils, lymphocytes, monocytes (which differentiate into macrophages or dendritic cells), eosinophils, basophils, and mast cells. The various components of the innate immune system can act independently or be coordinated in the process of inflammation.
Innate immunity
The non-cellular component of the innate immune system includes anatomical barriers and signaling molecules such as cytokines and complement proteins, while the cellular component includes a range of white blood cell types (leukocytes) that play various roles in responding to threats. White blood cells include neutrophils, lymphocytes, monocytes (which differentiate into macrophages or dendritic cells), eosinophils, basophils, and mast cells. The various components of the innate immune system can act independently or be coordinated in the process of inflammation.
Cecum
The normal gut flora hang out in the cecum, the blind outpouching of the large intestine
Normality
The normality (N) of a solution is the number of equivalents of reactive species per liter of solution (eq/L), for which we must define the reactive species. Normality is often used to express the concentration of H+ or OH− ions produced in acid-base reactions. For example, hydrochloric acid (HCl) generates one equivalent of H+ ions and one equivalent of Cl− ions per mole, while sulfuric acid (H2SO4) generates two equivalents of H+ ions and one equivalent of SO42− ions per mole. Acids and bases that can produce more than one H+ or OH− equivalent are polyvalent species.
Photon incident
The number of incident photons affects only the number of electrons, not their energies. The electron energies depend on photon energy, the cathode work function, and the potential difference between the cathode and anode.
Octahedral shape
The octahedral shape has six positions occupied by coordinated atoms,
Schizophrenia
The onset of schizophrenia generally occurs in late adolescence or early adulthood, so there are not many schizophrenic juveniles. Moreover, the percentage of violence attributed to individuals with schizophrenia is low (even including data for both genders and all age groups). In addition, female juveniles commit substantially less violent crime than do their male counterparts. Accordingly, a 1% increase per year in female juvenile schizophrenia is not likely to account for a 30% increase in total juvenile violent crime
optic chiasm
The optic chiasm houses the crossing fibers from each optic nerve. Specifically, the fibers coming from the nasal half of the retina in each eye cross in the chiasm to join the optic tract on the opposite side. Remember that the lens of the eye causes inversion, so images on the nasal half of the retina actually originate in the temporal visual field. This condition is called bitemporal hemianopsia.
Hybridization in CH4
The orbitals of an atom hybridize so that they are homogenous. For example, on paper, the central carbon in methane (CH4) has four valence electrons and would appear to have one s orbital and three p orbitals. In reality, however, these orbitals combine, or hybridize, to produce four identical sp3 orbitals. Hybridization between one s orbital and two p orbitals may also occur to produce three sp2 orbitals, or between one s orbital and one p orbital to produce two sp orbitals.
Inner mitochondrial membrane
The outer mitochondrial membrane is very permeable while the inner membrane is highly impermeable. The inner mitochondrial membrane is unique within the cell because it lacks cholesterol.
Follicular phase
The ovarian cycle begins with the follicular phase, followed by ovulation, which is in turn followed by the luteal phase. One ovum is released every menstrual cycle. A follicle matures in the follicular phase and releases the egg at ovulation. Then, in the luteal phase, the follicle is transformed into the corpus luteum, which secretes progesterone, helping to maintain the uterine lining. The corpus luteum decays towards the end of this period, and another cycle begins.
pI calculation in isolated protein
The pI can also be estimated for amino acids in isolation. For diprotic amino acids (i.e., those amino acids for which the side chain is neither acidic nor basic), the pI can straightforwardly be captured as the average of the two pKa values. For triprotic amino acids (i.e., those that have an acidic or basic side chain), the pI can be obtained by averaging the two acidic pKa values for acidic amino acids or the two basic pKa values for basic amino acids.
Plasma membrane structures
The plasma membrane of eukaryotic cells is primarily composed of a lipid bilayer of amphipathic phospholipids with hydrophilic heads and hydrophobic tails. It also contains cholesterol and membrane proteins. Transmembrane proteins are membrane-spanning proteins with hydrophilic cytosolic and extracellular domains and a hydrophobic membrane-spanning domain. Additionally, peripheral proteins are only transiently attached to integral proteins or peripheral regions of the lipid bilayer, and lipid-anchored proteins are covalently bound to membrane lipids without actually contacting the membrane directly. Membrane transport is accomplished through several mechanisms.
The portal vein
The portal vein carries blood from the intestines, gallbladder, pancreas and spleen to the liver. This vascular structure allows absorbed nutrients to travel directly to the liver for processing.
Cis and Trans Fats
The presence of one or more double bonds in a fatty acid has a significant effect on its physical properties. Naturally occurring unsaturated fatty acids generally have cis bonds, which introduce a degree of bending into the chain. This is especially true for polyunsaturated fatty acids with cis bonds. Such acids do not stack readily on top of each other, meaning that they tend to have lower melting and boiling points than the corresponding saturated fatty acids. In the context of plasma membranes, unsaturated fatty acids tend to make the membrane more fluid. Small amounts of trans fatty acids are produced in nature, but they are mostly present in the human diet as a result of the industrial processing of vegetable oils. Partial hydrogenation of unsaturated vegetable oils results in trans fats, which are more stackable than cis fatty acids and therefore are more likely to be solids at room temperature
Primary pathway of sound
The primary pathway allows sound waves to be transformed from mechanical disturbances in the environment to electrical impulses in the auditory complex, which ultimately result in an individual perceiving a noise.
RNA transcription
The process of going from DNA to RNA—more specifically, messenger RNA (mRNA)—is called transcription. Transcription takes place in the nucleus, and it results in the creation of an mRNA copy of a gene that can then be transported to the cytosol for translation into a protein. The DNA helix must be unzipped for transcription to take place, which means that some of the same machinery used for DNA replication has to be engaged, especially enzymes like helicase and topoisomerase. RNA polymerase is the enzyme responsible for RNA synthesis. In eukaryotes, it binds to a promoter region upstream of the start codon with the assistance of transcription factors, the most important of which is the TATA box. RNA polymerase travels along the template strand in the 3'-5' direction, synthesizing an antiparallel complement in the 5'-3' direction. The template strand is known as the antisense strand, and the opposite strand is known as the sense strand, because it corresponds to the codons on the mRNA that is eventually exported to the cytosol for translation. The immediate product of transcription in eukaryotes is not mRNA, but heterogeneous nuclear RNA (hnRNA). hnRNA must undergo a set of post-transcriptional modifications to become mRNA. Examples commonly tested on the MCAT include the 3' poly-A tail, the 5' cap, and splicing. The 3' poly-A tail is a string of approximately 250 adenine (A) nucleotides added to the 3' end of an hnRNA transcript to protect the eventual mRNA transcript against rapid degradation in the cytosol. The 5' cap refers to a 7-methylguanylate triphosphate cap placed on the 5' end of an hnRNA transcript. Similarly to the 3' poly-A tail, it helps prevent the transcript from being degraded too quickly in the cytosol, but it also prepares the RNA complex for export from the nucleus. In splicing, noncoding sequences (introns) are removed and coding sequences (exons) are ligated together. (Remember that exons are expressed). Each gene normally has multiple distinct exons that can be ligated in different combinations; that is, if a gene had a set of four introns named A, B, C, and D, possible alternate splicing combinations could include ABCD, ABC, ACD, ABD, BCD, and so on. This dramatically increases the amount of different, but related proteins that can be expressed from a single gene. Splicing explains why there are over 200,000 proteins in the human body, but only approximately 20,000 genes. Splicing is carried out by the spliceosome, a combination of small nuclear RNAs (snRNAs) and protein complexes.
Keratin
The protein that hair is primarily composed of
Proximal stimulus
The proximal stimulus is the stimulus registered by the sensory receptors (e.g., the pattern of light falling on the retina),
The psychodynamic model
The psychodynamic model focuses on internal aspects of an individual's psyche, and is associated with psychoanalytic theories of personality. Such theories are based upon the idea that our unconscious thoughts, feelings, and memories both determine our personalities and motivate our choices and actions.
Pareidolia
The psychological phenomenon that causes some people to see or hear a vague or random image or sound as something significant is known as pareidolia.
Internal validity info
Validity is a measure of how well a given experiment actually measures what it sets out to measure. If a study has internal validity, then the study has internally been well constructed, using things like large random samples, safeguards against confounding variables, reasonable and reliable processes and instruments, etc
PDH complex
The pyruvate dehydrogenase complex converts pyruvate (a three-carbon molecule that is produced by glycolysis) into acetyl-CoA, a two-carbon molecule that is fed into the citric acid cycle for further metabolism. As the name implies, the pyruvate dehydrogenase complex is indeed a complicated structure composed of multiple molecules. It contains three distinct enzymes that are physically linked with each other (pyruvate dehydrogenase being the most important for the MCAT, but pyruvate dehydrogenase is linked to dihydrolipoyl transacetylase and dihydrolipoyl dehydrogenase, which assist in some of the maneuvering involved with the coenzymes). The complex also requires the action of no fewer than five coenzymes: thiamine pyrophosphate (TPP), FAD, NAD, CoA, and lipoate. It is useful to note that several of them (thiamine, FAD, NAD, and CoA) have components derived from B vitamins.
Operant vs. Classical Conditioning
The quickest rule of thumb for distinguishing between the two is that operant conditioning involves changing the frequency of a behavior, whereas classical conditioning involves changing the cues that a behavior is associated with. The concepts of punishment and reinforcement are associated with operant conditioning.
LH and FSH
The release of estrogen and testosterone is stimulated by luteinizing hormone (LH), which is a peptide hormone secreted in response to low levels of these hormones. LH also stimulates estrogen release during the luteal surge of the menstrual cycle, leading to ovulation, and in response to the release of gonadotropin-releasing hormone (GnRH). Another peptide hormone released in response to GnRH that plays an important role in reproduction is follicle-stimulating hormone (FSH), which promotes the growth of ovarian follicles in females. It also has the effect of promoting spermatogenesis in males. During pregnancy, human chorionic gonadotropin (hCG) maintains the corpus luteum and induces it to secrete progesterone during the first trimester.
The repertory grid
The repertory grid is a test designed to reveal the respondent's way of construing the world according to the personal construct theory. This test if often used to determine an idiographic (the effort to understand the meaning of contingent, unique, and often subjective phenomena) measure of personality.
Biases
The representativeness heuristic is the tendency to make decisions about actions or events based upon our standard representations of those events. The closely related availability heuristic is the tendency to make decisions about how likely an action or event is based upon how readily available similar information is in our memories. Belief bias is the tendency that people have to judge things based not upon sound logic, but upon already held beliefs. Confirmation bias is a tendency that people have to focus on information that is in agreement with the beliefs they already have, rather than the information that is contrary to those beliefs.
The retrieval structure principle
The retrieval structure principle states that through practice individuals acquire memory mechanisms that facilitate the retrieval of information
SA node
The rhythm of heart contractions is controlled by the sinoatrial (SA) node, which is found at the roof of the right atrium. The cells in the SA node periodically send out action potentials, much like nerve cells. Gap junctions between the cardiac muscle cells allow the action potential to propagate throughout the tissue, causing contraction. The action potential flows from the SA node into the atria, but not into the ventricles because of a layer of insulating tissue. This causes both atria to contract, pushing the blood forward into the ventricles.
Heart contraction and SA node
The rhythm of heart contractions is controlled by the sinoatrial (SA) node, which is found at the roof of the right atrium. The cells in the SA node periodically send out action potentials, much like nerve cells. Gap junctions between the cardiac muscle cells allow the action potential to propagate throughout the tissue, causing contraction. The action potential flows from the SA node into the atria, but not into the ventricles because of a layer of insulating tissue. This causes both atria to contract, pushing the blood forward into the ventricles. The atrioventricular (AV) node allows the action potential to pass through to the ventricles after the atria have contracted. At this point, the ventricles must contract to push the blood out of the heart. Since the ventricles are larger than the atria, it is a bit more difficult to get them to contract together, so the signal is sped through the bundle of His and Purkinje fibers to all the muscle cells of the ventricles.
2nd structure of protein
The second level of protein structure refers to its two-dimensional arrangement (secondary structure). This folding is due to hydrogen bonds between groups along the peptide backbone that link different segments of the polypeptide chain to each other. These segments do not necessarily follow each other in the primary sequence and may be located in very distant regions of the polypeptide chain. There are two important types of secondary structure: the alpha-helix and the beta-sheet. In the alpha-helix, there are 3.6 residues per turn, which means that there is one residue every 100 degrees of rotation of the molecule. In beta-sheets, the protein is arranged into several β-strands, which are stretched segments of the polypeptide chain that are also kept together by hydrogen bonds. Beta-sheets may be parallel (the strands point in the same direction) or anti-parallel (the strands point in opposite directions).
The sensory epithelium
The sensory epithelium of the eyes, ears, and nose, along with all of the major structures of the brain, spinal cord, and peripheral nervous system, are derived from the ectoderm.
Sick role
The sick role has is a set of norms of expected behavior from sick people. The sick person: does not have to fulfill his or her normal roles; should seek medical attention, do as the doctor says, and try to get well; is not held accountable for her or his illness.
Signaling of muscle contraction
The signaling for contraction occurs when the neurotransmitter acetylcholine is released into the neuromuscular junction. Acetylcholine binds to receptors on the cell membrane, which is known as the sarcolemma in muscle cells, and the sarcolemma then depolarizes in response. This results in an action potential, and when the action potential reaches the sarcoplasmic reticulum, Ca2+ is released into the sarcoplasm (recall that this is just muscle-speak for the cytoplasm). Once in the sarcoplasm, Ca2+ can bind to troponin, which allows contraction to take place.
Signaling of muscle contraction occurs by
The signaling for contraction occurs when the neurotransmitter acetylcholine is released into the neuromuscular junction. Acetylcholine binds to receptors on the cell membrane, which is known as the sarcolemma in muscle cells, and the sarcolemma then depolarizes in response. This results in an action potential, and when the action potential reaches the sarcoplasmic reticulum, Ca2+ is released into the sarcoplasm (recall that this is just muscle-speak for the cytoplasm). Once in the sarcoplasm, Ca2+ can bind to troponin, which allows contraction to take place.
The socioeconomic gradient
The socioeconomic gradient in health refers to the graded relationship between social class and health, in which each "step" up on the hierarchy of social stratification tends to be associated with better health.
Paradigm: Functionalism
The sociological paradigm of functionalism makes a distinction between manifest, or intended, and latent, or unintended, functions of social activities. From the functionalist perspective, almost all social actions have both manifest functions and latent functions, both of which are connected to overall social stability.
Solvation layer (entropy)
The solvation layer (or shell) describes the structured organization of a solvent (e.g. water) around a solute (e.g. a polypeptide or protein). In the case of a protein which displays hydrophobic residues on its surface, the surrounding water will orient into a highly structured organization to optimize hydrogen bonding among water molecules (as hydrogen bonding with the presented hydrophobic side chains is not an option). This highly ordered rearrangement has a much lower entropy and is less favorable than if polar side chains were present on the surface of the protein. Thus, a conformation that buries its hydrophobic residues inside the protein leads to less disruption of water's hydrogen bonding, allowing for less structure and higher entropy, which increases the protein's conformational stability.
Why water has high heat capacity?
The specific heat capacity of water is 4.184 J/g∙°C, which is an unusually high heat capacity. This is due to hydrogen bonding. The high specific heat capacity of water is why the temperature of the ocean does not vary much over the course of the day, even though the sand will cool at night and burn your feet under the hot sun. Because water can "hold" a large amount of heat without experiencing a dramatic change in temperature, it is often used to cool extremely hot objects, as in nuclear technology applications.
Strength of correlation
The strength of a correlation is usually expressed as r, which can range from −1 to 1. An r value of 0 expresses no correlation whatsoever, while r values of −1 and 1 correspond to perfect negative and positive correlations, respectively. The strength of intermediate r values must be interpreted in context; an r value of 0.5 would be considered fairly strong for social sciences research, with many potential confounding variables, but fairly weak for the physical sciences. The related value of R2 expresses how well the regression line (the line of best fit) captures the data point, with 1 indicating a perfect correspondence between the regression line and the data and 0 indicating no correspondence.
What is R-Value?
The strength of a correlation is usually expressed as r, which can range from −1 to 1. An r value of 0 expresses no correlation whatsoever, while r values of −1 and 1 correspond to perfect negative and positive correlations, respectively. The strength of intermediate r values must be interpreted in context; an r value of 0.5 would be considered fairly strong for social sciences research, with many potential confounding variables, but fairly weak for the physical sciences. The related value of R2 expresses how well the regression line (the line of best fit) captures the data point, with 1 indicating a perfect correspondence between the regression line and the data and 0 indicating no correspondence.
Most stable conjugate base`
The stronger the acid
Reciprocal determinism
The study of behavior, or the range of actions performed by an individual, is a major focus of modern psychology. Social cognitive theory holds that our attitudes and behaviors are the result of observation of the attitudes and behaviors of others. According to this theory, we learn through direct emulation of the other people and things that populate our environment. Albert Bandura introduced a concept he termed triadic reciprocal causation, in which behavior, personal factors, and environment all influence our attitudes. The interaction between these three factors is called reciprocal determinism.
Optical rotation
The technique preferred for separating enantiomers
Cellulose structure
These bonds are also relevant to how humans (as well as most other non-plant forms of life) store energy in the form of glycogen. In humans, glycogen is stored in liver and muscle cells. Structurally, glycogen is similar to amylopectin in that it contains chains of glucose molecules connected by α(1→4) glycosidic bonds, with intervening α(1→6) glycosidic bonds that create branches; the main difference is that glycogen is more heavily branched than amylopectin, with branches occurring every 8−12 units. In contrast, a polysaccharide known as cellulose plays a major structural role in the cell walls of plants. Like starch and glycogen, it is a polymer of glucose, but unlike them, it incorporates the β-anomer of glucose, with glucose subunits connected by β(1→4) glycosidic bonds. This seemingly small structural distinction makes a world of practical difference, as humans lack the necessary enzymes to digest cellulose.
Group I and II introns
They are unique because no protein enzymes are involved in the splicing mechanism
Function of salt bridge
They re;lease anions and cations into the separate half cells to counteract the buildup of charges
Galvanic and Electrolytic Cells
The tendency for a species to spontaneously become reduced is measured using a parameter called the standard reduction potential. Reduction potentials (E°) are measured in volts and are defined relative to the standard hydrogen electrode (2 H+ (aq) + 2 e− → H2(g)), which is set at 0 V. Greater (more positive) reduction potentials indicate that a substance 'wants' to be reduced more, while smaller (more negative) reduction potentials indicate that a substance is not prone to reduction. Redox reactions can be carried out in special devices known as electrochemical cells. These cells must have two electrodes, which are where the redox half-reactions occur. The electrode where oxidation happens is known as the anode, while the electrode where reduction happens is known as the cathode. Therefore, a surplus of electrons is generated at the anode (because electrons are lost during oxidation), and they travel to the cathode. In a galvanic (or voltaic) cell, a spontaneous redox reaction is used to generate a positive potential difference that can drive current. The total standard potential generated by a cell, Ecell, can be calculated from the standard reduction potentials of the half-reactions. The simplest way of defining Ecell is presented below: Ecell = E°cathode − E°anode In contrast to a galvanic cell, an electrolytic cell uses a connected power source to conduct a nonspontaneous redox reaction. While galvanic cells have positive Ecell values (indicating spontaneity), electrolytic cells are characterized by negative Ecell values.
Cancer: Tumor (neoplasm)
The term "tumor" describes any abnormal proliferation of cells. Benign tumors remain localized, whereas malignant tumors (which are what the term "cancer" properly refers to) can invade other organs and tissues in the body in a process called metastasis. The first step in oncogenesis, tumor initiation, involves changes that allow a single cell to proliferate abnormally. This means that the cell must develop the ability to bypass regulatory steps of the cell cycle that normally help to limit mitotic proliferation. Tumor progression occurs as a cell develops the ability to proliferate even more aggressively, such that its descendants are selected for and come to predominate the growing tumor. In addition, malignant cells often undergo mutations that promote their own growth and the development of blood vessels to feed them (angiogenesis).
3rd Law of thermodynamics
The third law of thermodynamics allows us to calculate absolute entropy, but not absolute enthalpy. The enthalpy of a substance can only be calculated relative to other substances, and therefore enthalpy does not approach 0 as temperature approaches 0 K (known as "absolute zero"). The change in entropy (∆S) of a system is commonly understood as the change in the degree of randomness or disorder the system contains.
Third level of proein structure
The third level of protein structure, known as tertiary structure, refers to the actual three-dimensional shape of the native protein. These folds are caused and maintained primarily by hydrophobic/hydrophilic interactions and hydrogen bonds between the side chains of amino acids and between the amino acids and the protein's environment. Disulfide linkages between cysteine residues also contribute to tertiary structure by stabilizing the three-dimensional shape of the protein. Independent folding units of the protein structure are called domains. Some proteins contain a single domain, while others may contain several domains. The third level of structure is what gives proteins their biological activity and is the highest level of structure shared by all proteins.
Total Lung Capacity (TLC)
The volume of air in the lungs after a maximal inhalation. It is equal to vital capacity and reserve volume
What is competitive inibitor?
The way to determine the exact type of inhibition is through enzyme kinetic measurements of Vmax and Km. Vmax is the maximum velocity reached by the reaction, and Km is the substrate concentration required to reach Vmax/2. Competitive inhibition is when the inhibitor directly competes with the substrate for the active site on the enzyme. This increases Km since it now takes more substrate to ensure half of the active sites are occupied. If enough substrate is supplied, it will outcompete the inhibitor; therefore, Vmax does not change, although more substrate is needed to reach it.
Reverse transcriptase
This enzyme catalyzes the production of DNA from an RNA template. Reverse transcriptase thus must have DNA polymerase activity, since it builds a new DNA strand; it is also RNA-dependent, since it reads an RNA template.
Delta G and K
The ΔG° for the formation of fructose 6-phosphate from glucose 6-phosphate and ATP is equal to -3,600 cal/mol. This is the sum of the ΔG° for the formation of glucose 6-phosphate and ADP from glucose and ATP (-4,000 cal/mol) and the ΔG° for the reaction to which it is coupled, the formation of fructose 6-phosphate from glucose 6-phosphate (+400 cal/mol). -3,600 cal/mol can be easily converted to -3.60 kcal/mol. ΔG° < 0 for a given reaction indicates that reaction is spontaneous under standard conditions, and that at equilibrium, the products of the reaction predominate over the reactants. This is indicated by Keq > 1 and can be clearly seen in the relationship between ΔG and Keq: ΔG = -ln Keq where Keq > 1 returns a value of ΔG < 0, and Keq < 1 returns a value of ΔG > 0. Here, then, since ΔG is less than 0, Keq for the reaction is greater than 1. Spontaneity can also be defined in terms of other chemical concepts. By definition, a spontaneous reaction will lead to more products being present than reactants. This means that the equilibrium constant (Keq), which is broadly defined as [products]/[reactants], will be greater than 1 for a spontaneous reaction. This relationship is encoded in the equation ∆G°rxn = −RTlnK eq. Additionally, in the context of electrochemical cells, spontaneous reactions are associated with positive cell potentials (E° > 0). On Test Day, it is important to automatically recognize that spontaneity is equivalent to ∆G < 0, Keq > 1, and E° > 0.
Alpha decay
There are a number of ways that this can happen, and when it does, the atom is forever changed. There is no going back - the process is irreversible. There are four primary types of decay: alpha decay, beta decay (β+ and β−), gamma decay, and electron capture. In alpha decay, an alpha particle, containing two protons, two neutrons, and a +2 charge, is emitted.
What are decays?
There are a number of ways that this can happen, and when it does, the atom is forever changed. There is no going back - the process is irreversible. There are four primary types of decay: alpha decay, beta decay (β+ and β−), gamma decay, and electron capture. In alpha decay, an alpha particle, containing two protons, two neutrons, and a +2 charge, is emitted. In beta-minus decay, a neutron is converted into a proton in the nucleus, and a β− particle (an electron) is ejected to maintain charge balance. In beta-plus decay, a proton is converted into a neutron, and a β+ particle (a positron) is emitted to preserve charge. Gamma decay involves the emission of a gamma ray, which is a high-energy photon, from an excited nucleus. Finally, in electron capture, a nucleus "grabs" an electron, which changes a proton into a neutron.
Stages of behavioral change
There are five stages of behavioral change: pre-contemplation (before the individual is considering the change), contemplation (the individual's initial act of considering that they may want or need to change), preparation for action, action, and maintenance (the act of ensuring that the behavioral change "sticks"). When the behavioral change relates to addictive or harmful behaviors (as in an addict who decides to stop abusing drugs), maintenance often consists of relapse prevention, or methods designed to keep the individual from returning to that harmful set of actions.
Fives stages of behavioral change
There are five stages of behavioral change: precontemplation (before the individual is considering the change), contemplation (the individual's initial act of considering that they may want or need to change), preparation for action, action, and maintenance (the act of ensuring that the behavioral change "sticks"). When the behavioral change relates to addictive or harmful behaviors (as in an addict who decides to stop abusing drugs), maintenance often consists of relapse prevention, or methods designed to keep the individual from returning to that harmful set of actions.
The visuospatial sketchpad.
This is the part of working memory that processes visual and spatial information.
Conservation of energy
This principle is commonly applied to analyze scenarios in which kinetic and gravitational potential energy are interchanged, using the equation KEinitial + PEinitial = KEfinal + PEfinal. However, it is also possible to include elastic potential energy and electric potential energy if doing so would make sense in a given problem-solving context. If we need to account for nonconservative forces such as friction, we can do so using the equation Etotal - Enonconservative = Efinal.
Law of Effect (Edward Thorndike)
Thorndike's principle that behaviors followed by favorable consequences become more likely, and that behaviors followed by unfavorable consequences become less likely. . The law of effect involves increasingly shaped actions.
Reducing sugars
Those sugars that contain either hemiacetal or hemiketal functional groups. Benedict test is used to reduce these groups
The four types of macromolecules are:
There are four main classes of biomolecules: amino acids/proteins, lipids, carbohydrates, and nucleic acids. All of these classes except for lipids can occur as polymers, as proteins can be seen as polymers of amino acids, DNA and RNA are polymers of nucleic acids, and compounds such as starch, cellulose, and glycogen are polymers of carbohydrates.
Oxygen-containing functional groups:
There are several important oxygen-containing functional groups: alcohols (RC-OH), aldehydes (RC(=O)H), ketones (RC(=O)R'), and carboxylic acids (R(C=O)OH). Due to hydrogen bonding, alcohols and carboxylic acids have higher melting/boiling points than aldehydes and ketones, and can function as organic weak acids. Carbonyl (C=O) carbons have a significant partial positive charge and therefore often act as electrophiles. The -OH group of carboxylic acids can be replaced by other functional groups to form carboxylic acid derivatives, the most notable are amides (R(C=O)NR'R''), esters (R(C=O)OR'), acid anhydrides (R(C=O)O(C=O)R'), and acid halides (R(C=O)X), in increasing order of reactivity.
Uncompetitive inhibition
Uncompetitive inhibition is when the inhibitor binds to only the enzyme-substrate complex, and inactivates it. This causes the number of active enzyme-substrate complexes to decrease, thereby decreasing Vmax. Km also decreases to exactly the same degree as Vmax. Since both kinetic factors decrease to the same extent, the slope of the Lineweaver-Burk plot of enzyme activity will be the same as for the uninhibited enzyme.
Symbolic culture
To most people, culture is what makes their social environments meaningful. Meaningfulness is subjective, underscoring the role of symbolism in culture. Symbols are things that stand for something else, and in culture, symbols can evoke various reactions and emotions. Nonverbal communication can be symbolic, while other symbols are inanimate objects. Language, written or oral, is one of the most important symbolic aspects of culture. In addition to its symbolic aspects, languages allows for social communication on a much more complex level than would be otherwise possible. Ideas, beliefs, and symbols are considered to be part of symbolic or nonmaterial culture. In contrast, artifacts, art, buildings, and physical objects are part of material culture, which includes all of the physical objects used in a society.
How hydrophobic and solvation in water increase entropy?
To understand this principle, let us carefully compare what would happen if hydrophobic residues within a protein face an aqueous solution versus what would happen if hydrophilic residues face an aqueous solution, keeping in mind the polarity and excellent hydrogen-bonding properties of water. If hydrophilic—that is, polar—residues are facing the aqueous solution, then water will be able to hydrogen-bond freely with those residues, meaning that it will have relatively high entropy, which is energetically favorable. In contrast, water molecules will not be able to hydrogen-bond effectively with nonpolar residues, and as a result will form a highly-ordered solvation shell to minimize interactions with those residues. This highly-ordered shell represents a decrease in entropy, which is energetically unfavorable.
Entropy and Solvation layer
To understand this principle, let us carefully compare what would happen if hydrophobic residues within a protein face an aqueous solution versus what would happen if hydrophilic residues face an aqueous solution, keeping in mind the polarity and excellent hydrogen-bonding properties of water. If hydrophilic—that is, polar—residues are facing the aqueous solution, then water will be able to hydrogen-bond freely with those residues, meaning that it will have relatively high entropy, which is energetically favorable. In contrast, water molecules will not be able to hydrogen-bond effectively with nonpolar residues, and as a result will form a highly-ordered solvation shell to minimize interactions with those residues. This highly-ordered shell represents a decrease in entropy, which is energetically unfavorable. Thus, the three-dimensional structure of globular proteins in aqueous solution will minimize interactions between hydrophobic amino acid residues and water by incorporating them into the interior of the protein. A similar outcome occurs in the formation of micelles or bilayer membranes by amphipathic phospholipids, with the hydrophobic alkyl tails clustered together and the polar phosphate heads facing the aqueous solution.
Tonic stimulation
Tonic stimulation refers to constant nervous system stimulation at the neuromascular junction, which would lead to continual release of the nerotransmitter acetylcholine from pre-syanptic neurons. The Ach would bind Ach receptors on the muscle cells, causing efflux of calcium out of the sarcoplasmic retiulum into the cytosol of the muscle cell, leading to muscle contraction. Ca2+ is the main ion responsible for allowing for muscle contractions by binding troponin to move tropomysin away from the myosin-binding sites on actin.
Tonic stimulation
Tonic stimulation refers to constant nervous system stimulation at the neuromascular junction, which would lead to continual release of the neurotransmitter acetylcholine from pre-syanptic neurons.
Totipotent
Totipotency is the ability of a cell to develop into any mature cell types. It happens very early in embryo development...
Co-dominance
Traits where both versions are expressed (normal + abnormal) are called codominant. Another example of a codominant trait is blood type. Incomplete dominance would be the presentation of an intermediate trait which is not the case when two distinct cell types are formed. Complete dominance would be the production of normal blood cells only.
Transcription
Transcription occurs in the nucleoplasm of the nucleus. RNA polymerase uses the DNA template of the chromosomes to produce a pre-mRNA. The pre-mRNA is then processed to mRNA and moves to the cytoplasm for translation.
PCR and Edman degradation
Two final techniques to be aware of are the polymerase chain reaction (PCR) and Edman degradation. PCR is essentially "laboratory DNA replication," and uses a thermostable DNA polymerase and successive cycles of denaturation, annealing of primers, and extension of a new complementary strand to produce many copies of a sequence of interest. In contrast, Edman degradation is a technique used to sequence proteins via successive cleaving of terminal amino acid residues.
Ubiquitination
Ubiquitination targets a protein for degradation by a proteasome.
Umami
Umami is associated with amino acids.
DNA translation
Translation proceeds from the 5' to the 3' end, such that the amino terminus end of the protein is translated first. Therefore, mutations at the amino terminus will have the potential to affect the rest of the protein sequence and thus eliminate the effect of the transcription factor
Transmembrane protein
Transmembrane proteins consist of hydrophilic or polar amino acids at both ends of the protein, which associate with the extracellular and cytosolic fluids, which are both hydrophilic. However, for the protein to remain dissolved within the hydrophobic center of the lipid bilayer, the core of the membrane protein must contain a sufficient number of hydrophobic (non-polar) amino acids. Finally, when the transmembrane protein is an ion channel, the surface of the channel formed through the membrane must also contain hydrophilic residues in order for charged ions to easily pass through the channel
Trigonal planar
Trigonal planar molecules, like BF3, have three electron-rich areas and three bonded atoms at 120° angles, and linear molecules, such as CO2, have two electron-rich areas and two bonded atoms. Trigonal bipyramidal (e.g. PCl5) and octahedral molecules (e.g. SF6) have five and six electron-rich areas, respectively.
Troponin
Troponin is a complex of three proteins (troponin I, troponin C, and troponin T) required for muscle contraction in skeletal muscle and cardiac muscle, but not smooth muscle
Troponin requirement
Troponin is required for skeletal muscle contraction, but is not involved in smooth muscle contraction.
Euchromatin and Heterochromatin
Two distinct forms of chromatin exist: euchromatin and heterochromatin. Euchromatin is a loose configuration that is difficult to see under light microscopy and allows DNA to be readily transcribed. Throughout interphase (i.e., most of the cell cycle), DNA generally exists as euchromatin. Heterochromatin is the tightly coiled, dense form of chromatin that is visible during cell division and is present to a lesser extent even during interphase.
Euchromatin and heterochromatin
Two distinct forms of chromatin exist: euchromatin and heterochromatin. Euchromatin is a loose configuration that is difficult to see under light microscopy and allows DNA to be readily transcribed. Throughout interphase (i.e., most of the cell cycle), DNA generally exists as euchromatin. Heterochromatin is the tightly coiled, dense form of chromatin that is visible during cell division and is present to a lesser extent even during interphase.
Heterochromatin and Euchromatin
Two distinct forms of chromatin exist: euchromatin and heterochromatin. Euchromatin is a loose configuration that is difficult to see under light microscopy and allows DNA to be readily transcribed. Throughout interphase (i.e., most of the cell cycle), DNA generally exists as euchromatin. Heterochromatin is the tightly coiled, dense form of chromatin that is visible during cell division and is present to a lesser extent even during interphase.
Uncompetitive inhibition basic
Uncompetitive inhibition is when the inhibitor binds to only the enzyme-substrate complex, and inactivates it. This causes the number of active enzyme-substrate complexes to decrease, thereby decreasing Vmax. Km also decreases to exactly the same degree as Vmax. Since both kinetic factors decrease to the same extent, the slope of the Lineweaver-Burk plot of enzyme activity will be the same as for the uninhibited enzyme. The effects of an uncompetitive inhibitor cannot be overcome by increasing substrate concentration.
Uncompetitive inhibition info
Uncompetitive inhibition is when the inhibitor binds to only the enzyme-substrate complex, and inactivates it. This causes the number of active enzyme-substrate complexes to decrease, thereby decreasing Vmax. Km also decreases to exactly the same degree as Vmax. Since both kinetic factors decrease to the same extent, the slope of the Lineweaver-Burk plot of enzyme activity will be the same as for the uninhibited enzyme. The effects of an uncompetitive inhibitor cannot be overcome by increasing substrate concentration.
What is Uncompetitive inhibition?
Uncompetitive inhibition is when the inhibitor binds to only the enzyme-substrate complex, and inactivates it. This causes the number of active enzyme-substrate complexes to decrease, thereby decreasing Vmax. Km also decreases to exactly the same degree as Vmax. Since both kinetic factors decrease to the same extent, the slope of the Lineweaver-Burk plot of enzyme activity will be the same as for the uninhibited enzyme. The effects of an uncompetitive inhibitor cannot be overcome by increasing substrate concentration.
Uncompetitive inhibitor
Uncompetitive inhibitors bind their target enzymes only when the substrate is first bound to the enzyme. Since at higher substrate concentrations, the substrate-enzyme complex are more abundant, the uncompetitive inhibitor will work most effectively when the substrate concentration is the highest. Additionally, an increase in the inhibitor concentration results in increased enzyme binding and inhibition.
DNA vs RNA
Unlike DNA, RNA tends to exist in single-stranded form, rather than as a double-stranded double helix. Additionally, the sugar in RNA is ribose, which contains a hydroxyl (-OH) group on its 2′ carbon. (DNA contains deoxyribose, which lacks this 2′ hydroxyl group.) In addition to mRNA, which codes for protein production, several forms of non-coding RNA exist. These include transfer RNA (tRNA), which assists in translation, and small interfering RNA (siRNA) and microRNA (miRNA). siRNA and miRNA differ in their structure: miRNA strands are single-nucleotide strands incorporated into an RNA structure with a characteristic hairpin loop, while siRNA molecules are short and double-stranded. Both tend to be approximately 22 nucleotides in length, and both silence genes by interrupting expression between transcription and translation.
Notes for erythrocytes
Unlike almost all cells in the human body, erythrocytes (red blood cells) do not contain DNA or a membrane-bound nucleus. This allows these cells to have more space for oxygen-carrying hemoglobin molecules.
Gases properties
Unlike solids and liquids, the gas phase is not a condensed phase, as gas particles are relatively spread out and not in contact with one another. Gases lack a fixed shape and volume. The lack of a fixed volume—or compressibility—is especially important because it means that the density of a given gas is not constant. Rather, if the gas is forced into a smaller container, its density will increase as its particles pack more closely together.
Utilitarian organization
Utilitarian organizations are those in which members are paid for their efforts. These include businesses and corporations, from small town restaurants all the way up to McDonald's.
VSEPR theory
VSEPR theory uses Lewis structures and electronic relationships to determine the shapes of molecules, assuming that the distance between electron-rich regions will be maximized due to electronic repulsions. The number of regions of electron density is determined by the number of bonds and lone pairs around the central atom. Lone pairs of electrons take up more space than bonded atoms because electron pairs generate the strongest repulsive force. The number of lone pairs and bonded atoms associated with a central atom can be used to predict its bond angles and molecular shape.
Validity info
Validity is a measure of how well a given experiment actually measures what it sets out to measure. If a study has internal validity, then the study has internally been well constructed, using things like large random samples, safeguards against confounding variables, reasonable and reliable processes and instruments, etc. If a study is internally valid, we can then assess whether it has external validity—can the results of the experiment be generalized to other settings? A
Validity
Validity is a measure of how well a given experiment actually measures what it sets out to measure. If a study has internal validity, then the study has internally been well constructed, using things like large random samples, safeguards against confounding variables, reasonable and reliable processes and instruments, etc. If a study is internally valid, we can then assess whether it has external validity—can the results of the experiment be generalized to other settings? After all, if
Variable-ratio reinforcement
Variable-ratio reinforcement schedules tend to produce the highest response rates that are the most resistant to extinction, which is exactly why casinos use them.
vasodilation
Vasodilation (opening of blood vessels) of the capillaries in the dermis (in the skin) would increase blood flow at the skin and therefore allow for more heat exchange with the environment. This is a key mechanism to lower body temperature,
Vasodilation (in temp regulation)
Vasodilation and vasoconstriction are two of the main mechanims by which the body regulates internal temperature. As body temperature is higher than the environment, when surface capillaries dilate, heat radiates from the body to the environment
Veins facts
Veins, in contrast, carry low-pressure blood and therefore have much thinner walls. However, they have an interesting anatomical quirk of their own, due to the fact that they need to get blood back to the heart without the heart being able to provide a push. This is especially difficult in the lower limbs, where the veins must counteract the downward-pulling effects of gravity. This problem is solved by the presence of valves that allow blood to flow in only one direction.
Vesicles trafficking
Vesicles traffic proteins to be expressed on the surface of the plasma membrane. Following translation by a ribosome at the rough ER, the protein may undergo post-transnational modification, then it will be processed by the Golgi and budded off into a vesicle targeted for the membrane. The vesicle will then fuse with the plasma membrane so that the proteins on the inside of the vesicle membrane become the proteins on the outer leaflet of the plasma membrane.
Is virus a living organism?
Viruses are obligate intracellular parasites, which means that they must hijack host cells to replicate. The genetic material of viruses can be in the form of either single-stranded or double-stranded DNA or RNA. Single-stranded RNA viruses are further subdivided into positive-sense and negative-sense viruses. Positive-sense RNA viruses contain mRNA that can immediately be translated by the cell. In contrast, negative-sense RNA viruses contain RNA that is complementary to mRNA, meaning that mRNA must be synthesized by an enzyme known as RNA replicase that is carried in the virion.
Minerals and vitamins
Vitamins are non-macronutrient compounds that are vital for healthy functioning and cannot be synthesized in adequate quantities by the body, meaning that they must be obtained from external sources. The B vitamins and vitamin C are coenzymes used for various important reactions, and are water-soluble. Vitamins A, D, E, and K are lipid-soluble. Vitamin A plays a key role in vision, vitamin D in calcium and phosphate absorption from the gastrointestinal tract, vitamin E is an antioxidant, and vitamin K promotes coagulation. Like vitamins, minerals contribute to essential roles in the body and must be obtained from the diet, but unlike vitamins, minerals are inorganic. The most important minerals in the body are calcium, phosphorus, magnesium, sodium, and potassium.
Vitamins and minerals
Vitamins are non-macronutrient compounds that are vital for healthy functioning and cannot be synthesized in adequate quantities by the body, meaning that they must be obtained from external sources. The B vitamins and vitamin C are coenzymes used for various important reactions, and are water-soluble. Vitamins A, D, E, and K are lipid-soluble. Vitamin A plays a key role in vision, vitamin D in calcium and phosphate absorption from the gastrointestinal tract, vitamin E is an antioxidant, and vitamin K promotes coagulation. Like vitamins, minerals contribute to essential roles in the body and must be obtained from the diet, but unlike vitamins, minerals are inorganic. The most important minerals in the body are calcium, phosphorus, magnesium, sodium, and potassium.
Left and right hemisphere
Vocabulary skills tend to be lateralized to the left hemisphere, whereas visuospatial skills, music perception, and emotion processing tend to be lateralized to the right hemisphere.
.Voluntary muscles and reflex arch
Voluntary muscles may contract involuntarily due to a reflex arc. The classic example is the patellar tendon reflex, in which sudden stretching of the patellar tendon leads to an involuntary contraction of the quadriceps. Such contraction occurs before the signal has even reached the brain.
Aquaporins
Water, however, is a polar molecule and therefore cannot pass through the lipid-based plasma membrane as easily as similarly-sized nonpolar molecules can. However, H2O is still small enough to simply diffuse to some extent. This osmosis takes place in situations where water can diffuse through the membrane or other barrier, but solutes cannot; such a barrier is termed a semipermeable membrane. In such a setup, where only water can diffuse, it will travel through the membrane until the concentration of solutes is equalized. Water can diffuse more rapidly when specialized water channels, known as aquaporins, are also present, allowing the H2O molecules to travel via facilitated diffusion instead of relying on simple diffusion.
Shortcut for pH calculation
We can use our shortcut: -log [C x 10-E] = (E-1).(10-C).
Weber's Law Explained
Weber's Law (∆I/I = constant) predicts that the difference threshold, or the just-noticeable difference, will be a constant ratio of the original stimulus for all stimulus magnitudes. In other words, if the minimum noticeable difference between two weights is 0.05 kg, and the original weight was 1.0 kg, then this ratio is 0.05/1.0 = 5%. This indicates that for a 100 kg weight the just noticeable difference in mass will be different, but it will maintain the same ratio. In this case, it would be 5% of 100 kg, or exactly 5 kg.
Weber's Law
Weber's Law states that as the stimulus intensity changes geometrically, the perceived intensity of the stimulus varies arithmetically. Since the 3 intensities listed in the question form a geometric sequence (a = 2 and r = 1/3), they conform to the above tenet of Weber's law and
Weberian stratification
Weberian stratification states that wealth, prestige, and power influence the way that individuals treat one another.
Wechsler Scales of Intelligence
Wechsler Scales of Intelligence (WISC) scores are "normalized" to a mean of 100 and a standard deviation of 15. So 68% of the scores will be between 85 and 115.
First order reaction
When a graph of ln[A] vs. time is expected to be linear.
Phagosome
When a macrophage ingests foreign material, the material initially becomes trapped in a phagosome. The phagosome then fuses with a lysosome to form a phagolysosome. Inside the phagolysosome, enzymes digest the foreign object.
Total Internal refelection
When light passes from one medium to another and changes speed, it bends. Snell's law relates the refractive index—that is, how much the speed of a light wave changes—to how much the light bends upon entering the mew medium. Snell's law is expressed as n1sin(θ1) = n2sin(θ2). It is important to keep in mind that θ is defined with reference to the normal, or a line that runs perpendicular to the surface on which the wave is incident. An important special case occurs when light moves into a medium with a smaller index of refraction (that is, when n2 > n1). A classic example of this is when light is moving from water to air. As this happens, the angle θ with the normal will increase—in other words, the ray of light will bend further away from the normal. As the angle of the incident ray (θ1) increases, there will come a point where the angle of the refracted ray (θ2) reaches 90°. This is known as the critical angle. If we increase the angle beyond the critical angle, the light can no longer refract at all. Instead, all the light rays are reflected within the original medium. This is known as total internal reflection.
Muscle contraction size changes
When muscle contracts, the actin and myosin filaments slide over each other and the H-zone (myosin-only region), Z-lines (sarcomere boundaries), and I-band (actin-only region) all shrink, while the A-band (the entire myosin region) remains the same size. The opposite occurs upon muscle relaxation.
Sarcomere which change during contraction?
When muscle contracts, the actin and myosin filaments slide over each other and the H-zone (myosin-only region), Z-lines (sarcomere boundaries), and I-band (actin-only region) all shrink, while the A-band (the entire myosin region) remains the same size. The opposite occurs upon muscle relaxation.
Interference
When people study new material, any new information introduced between the initial learning (i.e., encoding) and retrieval, such as viewing a movie, will interfere with memory consolidation
Microsleeps
When the body is suffering from sleep deprivation, it uses microsleeps, (brief, unintended episodes of loss attention) to accommodate the lack of sufficient sleep. This continues until recovery is attained via adequate rest and recovery.
Lineweaver-Burk plots
When the experimental data are examined in the form of double reciprocal Lineweaver-Burk plots, the x- and y-axes are 1/[S] and 1/Vmax, respectively. Since these plots are a straight line, the slope of each line is Km/Vmax. The y-intercept on a Lineweaver-Burk plot represents 1/Vmax, while the x-intercept is −1/Km
Buoyency when the object is floaing
When the object is floating, the object's weight is balanced by the buoyant force; that is, mg = ρfluid Vsub g, or, after canceling the g's, m = ρfluidVsub. With ρfluid = 1.2ρwater = 1200 kg/m3 and Vsub = 5 × 10-3 m3, we find that
Capacitor details
When two conducting plates are connected to a battery, electrons move towards one plate. The positive plate loses electrons as well, and both plates eventually have equal and opposite charge, +Q and −Q. When a capacitor is fully charged, the capacitor has charge Q. We can relate the charge, capacitance, and voltage across the plates using the equation Q = VC (remember the home shopping network?). The voltage in this equation is the maximum potential difference that can be applied before the insulation of the dielectric breaks down. The electrical potential energy stored in the capacitor can also be related via the equations E = ½ QV = ½ CV2. Once fully charged, the capacitor can discharge a current across the circuit until the capacitor is "emptied" of all the stored charge. The MCAT may ask you to compare the difference in terms of charging when a battery is connected (V is constant) or disconnected (Q is constant).
World systems theory
World systems theory has been proposed in the context of globalization as a way of addressing how labor, capital, and expertise are distributed across core countries (such as Australia, nations in Western Europe, and the U.S. and Canada) that specialize in skilled forms of economic production and semi-peripheral and peripheral countries, which specialize in lower-skilled economic production and raw material extraction.
World systems theory basics
World systems theory has been proposed in the context of globalization as a way of addressing how labor, capital, and expertise are distributed across core countries (such as Australia, nations in Western Europe, and the U.S. and Canada) that specialize in skilled forms of economic production and semi-peripheral and peripheral countries, which specialize in lower-skilled economic production and raw material extraction.
X-ray crystallography
X-ray crystallography allows us to infer the 3D (secondary and tertiary) structure of the protein, but not its primary structure. It was the technique used by Rosalind Franklin to generate the images which led Watson and Crick to the structure of DNA.
Zimbardo's Stanford prison experiment
Zimbardo's Stanford prison experiment focused on the effects of power and authority on individuals. Participants designated as "guards" were given power over participants designated as "prisoners," and over time, the guards began to exhibit progressively more abusive and problematic behavior.
Frameshift mutation
a frameshift mutation only affects translation, not recombination or transcription since the enzymes carrying out these functions do not discriminate codons
Indirect therapy
aims to increase social support by educating and empowering family and friends of affected individual
Drug craving
an affective state in which there is a strong desire for the drug
An alternative movement
an alternative social movement creates limited change and only affects one individual or a small number of people.
Operon
an operon containing two genes in prokaryotic cells is transcribed from a single promoter upstream of the first gene in the operon.
Response bias
anything in a survey design that influences responses
Associative Learning/Conditioning
associative learning takes place when associations are made between stimuli or events that occur together.
Co-factor, conenzyme, and other
co-factor: inorganic group necessary for catalytic function in some way e.g. Mg+2 or iron-sulfur cluster coenzyme: organic group necessary for catalytic function in some way e.g. flavin or heme prosthetic group: A tightly or contently bound coenzyme
General personality disorder: Cluster C - Dependent
characterized by a continuous need for reassurance and depend on specific person to take actions and make decisions
Chirality and rotation
chiral compounds rotate planes of polarized light at angles unique to each compound. This is defined as the specific rotation [α] of the molecule. Compounds that produce clockwise (+) rotation of plane-polarized light are dextrorotatory (d), and compounds that produce counterclockwise (−) rotation are levorotatory (l). The specific rotation of a chiral compound in solution can be calculated according to the equation [α] =α/cl, where α is the observed rotation, c is the concentration in g/mL, and l is the length of the polarimeter tube in decimeters (dm). Chirality is emphasized on the MCAT because it is biologically relevant. Amino acids are chiral, and the L-stereoisomers comprise the overwhelming majority of amino acids that occur in nature. Correspondingly, D-isomers of carbohydrates occur in nature. Many enzymes are stereospecific, meaning that they only function for specific stereoisomers, and the biological functionality of compounds can vary depending on their chirality. Therefore, much attention in chemistry has been devoted to developing stereospecific reaction and purification procedures, many of which involve chiral catalysts or intermediaries.
Order of transmission
dendrites → cell body → axon → synapse
Depersonalization/derealization disorder
depersonalization/derealization disorder falls under the category of dissociatie disorders and it is defined as dissociation from the self and/or one's surroundings.
Sensory Bias
development of a trait to match a preexisting preference that exists in the population (ex. fiddler crabs are naturally attracted to structures that break up the level horizon because they may indicate a food source; male crabs build pillars around their territory to attract mates)
Drive Theory of Motivation
deviations from homeostasis create unmet physiological needs that result in tension that directs behavior to meet the need and ultimately bring the system back to homeostasis
Attribution error
error made in attributing the causes for someone's behavior to their membership in a particular group, such as a racial group
fMRI basic
fMRI is a technique that would allow the researchers to measure brain activity. fMRI measures blood oxygenation levels (BOLD signal) in brain tissue, allowing scientists to correlate certain activities with specific regions of the brain.
Hormones that increase blood glucose
glucagon, cortisol, epinephrine, norepinephrine, and somatostatin
Simple half life info
half-life (t1/2), which is the time required for one-half of the parent isotopes in a sample to decay into daughter (radiogenic) isotopes. If we know the half-life of a material, then we can determine how much of a sample is lost (1- ½n) or remains (½n) at any given time, as expressed in the number of half-lives that have passed (n).
Ketone bodies facts
if too much glucose remain in the blood, cells may accumulate excess acetyl-CoA molecules that cannot be shunted into the citric acid cycle because the intermediaries of the citric acid cycle, especially oxaloacetate, have been siphoned off to gluconeogenesis. This excess acetyl-CoA can be used to produce acetone, D-β-hydroxybutyrate, and acetoacetate, which are known as ketone bodies. The latter two compounds are both acidic, meaning that when present in the blood at an excessively high level, they can cause the blood pH to drop, resulting in a condition known as ketoacidosis. In patients with underlying diabetes, this condition is known as diabetic ketoacidosis. Ketoacidosis can be smelled on a patient's breath, because acetone accumulates to a noticeable level.
Ipsilateral
ipsilateral projection refers to a given projection arising on one side of the body and being maintained on the same side of the brain
speed of sound
is proportional to the square root of the medium's bulk modulus
Hydrostatic pressure
it is directly proportional to the depth and inversely proportional to the height
Acid anhydride
it is not soluble in water because of its high reactivity it converts to acid in water
Mesoderm
kidney, heart, muscle, dermis of skin, skeleton, gonads,
Kinesin
kinesins are motor protein that travel from the cneter or negative pole to the periphery or positive pole of the cell.
Nucleophile and Electrophile
lectron-rich molecules tend to act as nucleophiles when a covalent bond is being made. They also tend to act as Brønsted-Lowry bases when making a bond to an H+, or as Lewis bases when a coordinate bond is formed. Such bonds are so weak that they repeatedly form and dissociate at standard temperatures. Electron-poor molecules play the converse roles. Such molecules function as electrophiles in reactions that yield covalent bonds, as Brønsted-Lowry acids when making a bond to an H+, or as Lewis acids when coordinate bonds are formed. Molecules with electron-rich or electron-poor areas have important, characteristic, and predictable patterns of reactivity. For example, amines are good nucleophiles due to the presence of a lone pair of electrons. The carbons in carbonyl groups (C=O) are electron-poor, making them good electrophiles. One of the first steps to take when determining electron density is to look for C atoms bound or near to highly electronegative atoms (O, F, N) and for pi bonds, which can undergo resonance, allowing for molecules to be better nucleophiles.
1st order reaction graph
ln [A] vs time is expected to be linear
Longitudinal study
longitudinal cohort design followed a group of individuals and assessed them at multiple intervals over a period of two years.
Magnetic field
magnetic field can only be created by moving charge
General personality disorder: Cluster A - Paranoid
marked by pervasive distrust of others and suspicion regarding their motives and may be in prodromal phase of schizophrenia
Resource mobilization theory
model of social movements that emphasizes political context and goals but also states that social movements are unlikely to emerge without the necessary resources
Shortcut for calculating pH
pH and pOH values can be estimated given a certain concentration using the following shortcut: p(N × 10−M) = (M−1).(10−N), such that a solution with an H+ concentration of 4 × 10−8 will have a pH = (8−1).(10−4) = 7.6.
Correspondent inference theory
people pay closer attention to intentional behavior than accidental beavior when making attributions especially if the behavior is unexpected
Primary and secondary kinship
primary kinship involves a direct relationship, such as that between a brother and sister or between a father and daughter. Secondary kinship exists between an individual and "the primary kin of that person's primary kin." For example, the relationship between a grandson and his paternal grandmother would typically be secondary kinship, since the grandson is primary kin with his own father, who is primary kin with his mother (the grandmother). Finally, tertiary kin is one step further removed, and can refer to primary kin of one's primary kin's primary kin (three levels!) or to the secondary kin of one's primary kin, such as one's husband's grandmother.
Primary transcript of mRNA
primary transcript an be processed by many different ways by nuclear spliceosome.
Prion protein
prion pathology is only observed in the central nervous system of the infected person or animal.
Psychophysical testing methods
psychophysical testing methods (such as the Method of Limits) directly assess our perception of stimuli in relation to their true physical properties.
2nd order reaction
rate= k [A]^2; graph of 1/A is straight line
Distinctiveness cues
refer to extent to which a person engages in similar behavior across a series of scenarios; likely to form situational attribution to explain it
socioeconomic gradient in health
reflects that those with the lowest status are less healthy than those in the middle, who are less healthy than those at the top
Indicator Trait
signify overall good health and wellbeing of an organism which increases its attractiveness to mates
X-linked recessive disorder in female
similar to autossomal recessive disroder
Implicit personality theory
states that there are sets of assumptions people make about how different types of people, their traits, and their behavior are related
Rough and Smooth Endoplasmic Reticulum
the endoplasmic reticulum is a net-like organelle that extends out from the nuclear membrane. It is divided into the rough ER and the smooth ER. The rough ER is rough because it is covered with ribosomes, which are the site of protein synthesis. In contrast, the smooth ER does not have ribosomes, and is involved in lipid metabolism (both synthesis and breakdown), the production of steroid hormones, and detoxification. Lysosomes are the garbage disposal system of the cell; material from outside the cell enters the lysosomes through endocytosis, while material from inside the cells enters through autophagy. They contain hydrolases that operate best at acidic pH levels, and the lysosomes are therefore kept at a pH of 4.5-5.0.
The fundamental attribution error
the fundamental attribution error refers to stressing the importance of dispositional (i.e., personality) factors in one's explanations of other people's behavior and underemphasizing situational factors.
Endoderm
the inner germ layer that develops into the lining of the digestive and respiratory systems, pancreas, liver, thymus, and thyroid
Kinetic parameters of enzyme
the kinetic parameters Vmax and Km are reported via Michaelis-Menten plots. However, Lineweaver-Burk plots may also be used. When the experimental data are examined in the form of double reciprocal Lineweaver-Burk plots, the x- and y-axes are 1/[S] and 1/V, respectively. Since these plots are a straight line, the slope of each line is Km/Vmax. The y-intercept on a Lineweaver-Burk plot represents 1/Vmax, while the x-intercept is −1/Km. These double-reciprocal plots are especially useful for distinguishing between competitive and noncompetitive inhibitors.
Drug tolerance
the tendency for larger doses of a drug to be required over time to achieve the same effect
George Kelly's Personal Construct Psychology
thought of the individual as a scientist who devises and tests predictions about behavior of significant people in his or her life
Beta amino acids
β amino acids have their amino group bonded to the β carbon rather than the α carbon. Glycine is the only amino acid without a β carbon, which means that making β-glycine would not be possible