Biology 110, final exam study guide
Define membrane potential. Describe the 3 factors that contribute to it.
-Difference in charge between the inside (more negative) and outside (more positive) of the neuron, making it electrically polarized -The plasma membrane barrier separates the charges -Ion concentrations differ between the inside and outside of the cell
Explain X-linked traits using an example.
-many genes are found on the x chromosomes but not the y -hemophilia a caused by recessive x linked gene -recessive x linked disorders are common in sons, they inherit their alleles from their mothers and pass it on to their daughters
What does ATP synthase do? Where?
-synthesizes ATP using an enzyme, source of potential energy -inter membrane space
Discuss 3 important ideas from Mendel's monohybrid crosses.
-traits may exist in two forms, dominant and recessive -an individual carries two genes for a given character, and genes have variant forms (alleles) -the two alleles of a gene separate during the process that gives rise haploid cells and gametes, so each sperm and egg receives only one allele
Describe the 3 types of neurons.
1. sensory neurons- detect info from outside world or internal body conditions (afferent neurons- transmit info to CNS) 2. motor neurons- Send signals away from CNS (efferent neurons) to elicit responses 3. interneurons- Form complex interconnections between other neurons
Write the overall chemical reaction for photosynthesis. What 3 words describe this type of reaction?
6 CO2+6 H2O-->C6H12O6+6 O2
Explain in general Mendel's two-factor cross. Diagram an example.
Follow the inheritance of 2 different traits-2 genes linked are always inherited as a unit are 2 genes are independent and randomly distributed
Explain how hair cells work in general.
Specialized epithelial cells Deformable stereocilia (actin-based) resemble hairs Ion channels open or close when stereocilia bend which changes membrane potential Found in the ear and equilibrium organs, body surface of fish and some amphibians
Define glia and give functions of the types.
These are cells that surround the neurons and perform numerous supporting roles. Types include: -oligodendrocytes (CNS)/ Schwann cells (PNS), which make up the myelin sheath that surround the axons of neurons -astrocytes (they look like stars, hence "astro"), which provide metabolic support and are involved in forming the blood-brain barrier -Microglia, which remove cellular debris produced by damaged or dying cells -Radial glia, which form tracks for neuronal migration in embryos Astrocytes and radial glia also function as stem cells to produce more glia and neurons
What is the refractory period? Why is it important?
This is the time period when a cell is unresponsive to another stimulus while its inactivation gate of Na+ channels are closed. It's important because this period ensures that the action potential doesn't move backwards toward the cell body.
Explain the function of testosterone and how it is regulated.
testosterone acts on: -sertoli cells and germ cells to stimulate spermatogenesis -stimulates growth of male reproductive tract and genitalia during development and puberty -stimulates development of male secondary sexual characteristics (facial hair, horns on bulls, bright feathers of peacocks) -FSH (with testosterone) stimulates sertoli cells and spermatogenesis -controlled by negative feedback -increased GnRH at puberty initiates release of LH and FSH
Describe what happens at a chemical synapse.
the presynaptic nerve cell contains vesicles of the neurotransmitter, exocytosis releases neurotransmitter into the synaptic cleft. It then diffuses across the cleft and binds to channels or receptors in the post-synaptic cell membrane.
Distinguish between the 3 types of transporters.
uniporter-bind a single ion on molecule and transport it across the membrane (active) synporter-bind two or more ions or molecules and transport them in the same direction (active) antiporter-bind two or more ions or molecules and transport them in opposite directions (active)
Describe color blindness.
(Fig. 43.19) X-Linked trait=more males have it Red-green colorblindness-either don't see the number at all or see the wrong number.
Give examples of trisomies in autosomal chromosomes, and trisomies and monosomies in sex chromosomes in humans.
-autocomal chromosomes: trisomy 21 (down syndrome), trisomy 18 (edward syndrome), and trisomy 13 (patau syndrome) -sex chromosomes: monosome (turner syndrome) and trisomy (jacobs syndrome)
Describe the parts and functions of the human male reproductive system.
-genitalia consists of penis and scrotum -scrotum holds testes where sperm develop at 2C lower than core body temperature -each testis composed of seminiferous tubules (site of spermatogenesis) and Leydig cells (secrete testosterone) -sperm released into lumen of seminiferous tubules -sertoli cells provide nutrients and protection to developing sperm
Discuss types of neurotransmitters.
1. Acetylcholine- One of the most widespread neurotransmitters, released at neuromuscular junction, excitatory in brain and skeletal muscles but inhibitory in cardiac muscles 2. Biogenic amines- abnormally high or low levels associated with a variety of disorders (schizophrenia, Parkinson disease, and depression) 3. Amino acids - includes glutamate, the most widespread excitatory neurotransmitter, and GABA, the most common inhibitory neurotransmitter 4. Neuropeptides - often called neuromodulators, they can alter the response of the postsynaptic neuron to other neurotransmitters, and includes opiate peptides (endorphin, enkephalin), and oxytocin 5. Gaseous neurotransmitters - not sequestered into vesicles, produced locally as needed, short-acting to influence other cells by diffusion, includes nitric oxide
Explain the 2 factors that increase the speed of conduction.
1. Broad axons provide less resistance and the action potential moves faster 2. The presence of a myelin sheath (made up of either oligodendrocytes or Schwann cells) around the axon also increases the speed of the action potential
Discuss health issues related to the nervous system.
1. Neurotransmission disorders: -genetic processes can increase or decrease synaptic activity affecting emotions and behavior -major depression thought to result from decreased activity of synapses releasing biogenic amines 2. Recreational drugs: -enhance or interfere with neurotransmission -drugs produce changes or imbalances in neurotransmission 3. Conduction disorders: - cretinism - axons failed to become myelinated during fetal life due to insufficient thyroid hormone in fetus - multiple sclerosis - patient's own body destroys myelin as if it were a foreign substance, which impairs the function of myelinated neurons controlling movement, speech, memory, and emotion
Draw a picture showing the relationship between a mRNA sequence and a polypeptide sequence. On the mRNA, label the 5' and 3' ends, start and stop codons, and other codons. Using genetic code table, draw the corresponding polypeptide and label the N-terminus, C-terminus, peptide bonds and each specific amino acid.
5'-3': antiparallel N-terminus: location of the first amino acid in a polypeptide; amino acid terminus C-terminus: location of the last amino acid in a polypeptide; also known as the carboxyl terminus peptide bonds: covalent bond that links amino acids in a polypeptide amino acids: building blocks of proteins; have a common structure in which a carbon atom, called the a-carbon, is linked to an amino group and a carboxyl group; the a-carbon also is linked to a hydrogen atom and a particular side chain
Explain the knee-jerk reflex arc.
A series of connections between neurons used to transmit info is called a circuit. A simple circuit is called a reflex arc, which consists of only a few neurons and allows for quick responses to inputs from sensory neurons. Example: a tap below the kneecap stretches the patellar tendon, which acts as a stimulus. This stimulus initiates a reflex arc that activates (+) a motor neuron that causes the extensor muscle on top of the thigh to contract, while at the same time, an interneuron inhibits (-) the motor neurons of the flexor muscle, causing it to relax.
Tell the story of the 2 main processes of photosynthesis (draw and explain Figure 8.3).
An overview of the two stages of photosynthesis: light reactions and the Calvin cycle. The light reactions, through which ATP, NADPH, & O2 are made, occur at the thylakoid membrane. The Calvin cycle, in which enzymes use ATP and NADPH to incorporate CO2 into carbohydrates, occurs in the stroma.
Describe the 3 layers of meninges of the CNS and the CSF (cerebrospinal fluid).
CNS encased in bone and 3 layers of meninges Dura mater - outer thick layer Arachnoid mater - numerous connections to inner layer Pia mater - inner thin membrane on surface of brain and spinal cord Cerebrospinal fluid circulated through subarachnoid space Between arachnoid mater and pia mater Absorbs physical shocks Transport Ventricles and central canal
Distinguish between CNS and PNS.
CNS-nervous system; brain and spinal cord PNS-route information into and out of the CNS at separate regions along the spinal cord
Describe the gustatory structures in humans (Figure 43.26).
Chemosensory cells that detect particular molecules in food Papillae (bumps) collect food molecules and direct them to sensory receptor cells in taste buds Tips of sensory receptor cells have microvilli that extend into taste pore
Describe the positive feedback cycle in childbirth.
Childbirth is initiated by hormonal action and other factors, but the initial event is the increase in estradiol and oxytocin in the mother's blood. Oxytocin from the posterior pituitary stimulates the smooth muscle of the uterus to contract, while huge levels of estradiol increases the uterus' smooth muscles' sensitivity to oxytocin by stimulating smooth muscles' production of oxytocin receptors. The pressure of the fetus' head also stretches the smooth muscle, which triggers more oxytocin release. This is called a positive feedback cycle because the more the uterus contracts, the more oxytocin is released, and the more oxytocin is released, the more the uterus contracts.
Lis the proteins with their functions involved in DNA replication in order of when they function.
DNA helicase-binds to DNA and travels to 5'-3' using ATP to uncoil the helix and break the hydrogen bonds between the nitrogenous bases and move the replication fork forward DNA topoisomerase-relieves additional coiling, or supercoiling, ahead of the replication fork single strand binding proteins-keep the parental strands open to act as templates and keep them from rebounding before replication occurs DNA polymerase-covalently links nucleotides with exergonic dehydration reactions by using free floating nucleotides (deoxynucleoside triphosphate monomers) and linking them like substrate in a 5'-3' direction DNA primate-makes RNA primers DNA ligase-links adjacent Okazaki fragments on the lagging strand to create one continuous strand, ligase means to stick together
Comport and contrast DNA and RNA.
DNA-sugar is deoxyribose, thymine instead of uracil, 2 strands=double helix, one form RNA-sugar is ribose, uracil instead of thymine, single strand (usually), many forms (mRNA, tRNA, rRNA) both-pentose sugars; adenine, guanine, cytosine
Define sensory receptor.
Detects stimulus and initiates signal transduction by creating action potentials in the same or adjacent cells Either neurons or specialized epithelial cells When the response is strong enough an action potential is sent to the CNS
What happens during each trimester of pregnancy?
First Trimester: During the first two months of pregnancy, the organs of the embryo develop. At the end of this trimester, the rudiments of the organs are present, and the developing fetus is about an inch long. Second Trimester: This trimester is an extremely rapid phase of growth. Like all trimester, it lasts for three months. Third Trimester: The lungs of the fetus mature to function on their own at birth and the fetus typically positions itself above the cervix.
Draw a side view of the cerebrum, label the 4 lobes, and list the functions.
Frontal - conscious thought and social awareness Parietal - attention and making association between events and incoming information Occipital - vision Temporal - language, temporal, and some types of memory
Describe the structure and function of the Golgi, lysosomes, vacuoles, mitochondria, chloroplasts, and peroxisomes.
Golgi-stacks of fattened membranes, with each flattened membrane enclosing a single compartment processing, protein sorting and secretion lysosomes-small organelles found in animal cells that break down macromolecules; contain many acid hydrolase (enzymes that use molecules of water to break covalent bond-hydrolysis); can also break down carbohydrates, proteins, lipids and nucleic acids vacuoles-prominent organelles in plant, fungal cells and certain proteins; contain fluid sometimes solid substances; central-helps with turgor pressure in plant cells; contractile-maintain cells volume in protists; food-degradation (break down macromolecules) in protists peroxisomes-small organelles found in eukaryotes; consists of a single membrane that encloses a fluid-like lumen; catalyze a variety of chemical reactions (break down organic molecules and others that are biosynthetic); detoxify and makes peroxide in the cell (dangerous in cell if released) mitochondria-threadlike or granular-shaped, size of bacteria; outer and inner membrane separated by inter membrane space; main role is to produce ATP, convert energy that is stored to be ready for modification, and breakdown several types of cellular molecules chloroplast-capture light energy and use some of that energy to synthesize organic molecules (glucose-photosynthesis); includes inner and outer membrane with inter membrane space (geranium, thylakoid, stroma)
Thoroughly explain Figure 6.5
It's the activation energy of an exergonic chemical reaction. The activation energy (Ea) is needed for molecules to achieve a transition state. One way that enzymes lower the activation energy is by straining chemical bonds in the reactants so less energy is required to attain the transition state. A second way is by binding two reactants so they are close to each other and in a favorable orientation.
Draw a x-y graph showing resting membrane potential, threshold potential, an action potential, then resting again. Label the state of K+ leak channels, VG Na+ channels, and VG K+ channels from beginning to end of the graph.
K+ leak channels- VG Na+ channels- VG K+ leak channels-
Tell the story of how leaves carry out photosynthesis (draw and explain Figure 8.2).
Leaf organization. Leaves are composed of layers of cells. The epidermal cells are on the outer surface, both top and bottom, with mesophyll cells sandwiched in the middle. The mesophyll cells contain chloroplasts and are the primary sites of photosynthesis in most plants.
Describe the vestibular system in vertebrates (Figure 43.9).
Located in inner ear near cochlea Hair cells in utricle and saccule detect linear motion Hair cells in semicircular canals detect rotational motion
List the 5 types of sensory receptors and the type of stimuli detected by each.
Mechanoreceptors - respond to mechanical force Thermoreceptors - respond to cold and heat Nociceptors or pain receptors - respond to extreme heat, cold, and pressure, as well as to certain molecules such as acids Electromagnetic receptors - detect radiation within a wide range of the electromagnetic spectrum Photoreceptors - respond to visible light energy Chemoreceptors - respond to specific chemicals
Describe in detail what occurs during Meiosis I and Meiosis II.
Meiosis I: prophase-synapsis and crossing over; replicated chromosomes condense and bivalents form; nuclear membrane breaks down prometaphase-spindle forms and bivalents are attached to kinetochore microtubules metaphase-bivalents organized along metaphase plate as double row anaphase-bivalent pairs separate and move toward opposite poles telophase-chromosomes unravel and nuclear membranes form (cytokinesis) Meiosis II: prophase-sister chromatids condense and spindle starts to form; nuclear envelop dissociates prometaphase-sister chromatids attach to spindle via kinetochore microtubules metaphase-sister chromatids align along metaphase plate; each pair of sister chromatids is attached to both poles anaphase-sister chromatids break apart and are separated and move toward opposite poles telophase-chromosomes condense and nuclear envelope reforms; forms four cells
Describe in general Mendel's single-factor (monohybrid) cross. Diagram a single factor cross for plant height beginning with the P generation, then F1 and then F2. Include genotype and phenotype ratios for each generation.
Mendel began his investigations by studying the inheritance patterns of pea plants that differed in a single character. A cross in which an experimenter follows the variants of only one character is called a single-factor cross.
Describe meningitis and Alzeihmer's disease.
Meningitis: -Viral or bacterial infection of meninges -Increased pressure effects range from severe headaches to death -Bacterial infection can be treated with antibiotics -Viral form less serious and short lasting -Vaccine has reduced cases but still dangerous and prevalent disease (especially close quarters like college dorms) Alzheimer's disease (AD): -Leading worldwide cause of dementia -Characterized by memory loss and intellectual and emotional function -Definitive diagnosis can only be made after death -2 noticeable changes - senile plagues and neurofibrillary tangles -Not clear how changes influence function
Describe olfactory structures in humans (Figure 43.24).
Olfactory sensitivity on mammals depends on the density of olfactory receptor cells 5 million in humans vs. 220 million in dogs Olfactory receptors have long cilia with receptors to bind odor molecules Binding results in action potentials being sent to olfactory bulb at the base of the brain
Which 2 cell types are "excitable"? What 2 types of gated ion channels do they have?
Only neurons and muscle cells are excitable/generate an action potential, and they have voltage-gated ion channels (open/close in response to voltage change) and ligand-gated ion channels (open/close in response to ligands/chemicals)
Describe how polymers are formed from monomers and how monomers are formed from polymers.
Polymerization is the process of covalently bonding the smaller monomers into the polymer. During polymerization, chemical groups are lost from the monomers so that they may join together. Polymers are then broken into monomers.
Beginning with the cornea and ending with the optic never, name and give the function of each part of they eye involved in photoreceptor in humans. (Figure 43.14, 43.21).
Sclera - strong outer white sheath Cornea - continuous with sclera but thin and clear 2 cavities - anterior holds aqueous humor, posterior holds thick vitreous humor (maintains eye shape) Iris - pigmented smooth muscle controlling size of pupil Look at the pic for the rest Cornea and lens bend incoming light Lens is adjusted by ciliary muscles to focus light (accommodation)
Beginning with the pinna and ending with the auditory nerve, name and give the function of each part of the ear involved in audition in humans (Figure 43.5, 43.6, 43.7).
Sound waves enter the outer ear in the pinna which captures sound waves Tympanic membrane (eardrum) vibrates back and forth Ossicles transfer vibration to oval window Sends pressure waves through cochlea (collect sound) Waves travel from auditory canal to tympanic canal and dissipate against round window Waves pass under basilar membrane moving it up and down Mechanical forces transduced into electrical signals by organ of Corti Up-and-down vibration of basilar membrane move hair cells Stereocilia bending causes action potentials in auditory nerve
Use a specific example to show how cells use ATP hydrolysis to run an endergonic reaction.
The ATP site of an enzyme splits the ATP molecules creating 7.3 Kcal of chemical energy. This drives the endergonic reaction which combined with AT hydrolysis become favorable.
Using the cheeseburger analogy, list the events in order to form the initiation complex during translation.
The mRNA binds to the small ribosomal subunit which is like a burger patty binding to the bottom bun, then the tRNA binds to the start codon in mRNA which is like the cheese binding to the patty, and lastly the large ribosomal unit binds, this is like placing the top bun on the cheeseburger.
Thoroughly explain Figure 51.9.
The ovarian and uterine cycles in a human female. The ovarian cycle is divided into the follicular and luteal phases. The uterine cycle is divided into menstruation and the proliferative and secretory phases.
What is the relationship between brain complexity and size and convolutions of the cerebrum? How are body mass and brain mass related? Any exceptions?
The size of the cerebrum and the surface area of the cerebral cortex (convolutions) increase with more complex nervous systems. Body mass and brain mass are proportional, with exceptions (humans and dolphins). Greater size and folding provides more surface area for greater processing and interpretation of information.
Discuss causes of vision and hearing loss.
Visual disorders - 3 causes of vision loss: -Glaucoma - drainage of aqueous humor blocked and pressure inside eye rises damaging retinal cells 10% of all cases of blindness in US -Macular degeneration - photoreceptor cells in and around fovea lost 25% of all cases of blindness in US -Cataracts - accumulation of protein clouds the lens Lens can be removed if required 70% of people have cataracts by the age of 75 Deafness: -Usually damage to hair cells within cochlea -Can result from problems in brain, nerves, or hair cells -Most significant cause is repeated, long-term exposure to loud noise -1 in 7 Americans are exposed daily to dangerous noise levels as a result of their occupation -Cochlear implants can be implanted to generate electrical signals in response to sound waves
Distinguish between anabolic and catabolic pathways. Give examples of each.
anabolic-involve synthesis of larger molecules from smaller precursor molecules catabolic-result in breakdown of larger molecules into smaller ones
Sketch 3 adjacent water molecules in ice. Indicate each atom, polar covalent bond, and hydrogen bond.
atom-smallest function until of matter that forms all chemical substances and cannot be further broken down into other substances by ordinary chemical or physical means polar covalent bond-covalent bond between two atoms that have different electronegativities; the shared electrons are closer to the atom os high electronegativity than the atom of lower electronegativity; distribution of electrons around the atoms creates polarity, or difference in electric charge, across the molecule hydrogen bond-a weak chemical attraction between a partially positive hydrogen atom of a polar molecule and a partially negative atom of another polar molecule
What is the electron transport chain? What is the final electron acceptor?
consists of a group of protein complexes and small organic molecules embedded in inner mitochondrial membrane; electrons are passed from one component to the next in a series of redox reactions -final acceptor: O2, ATP synthase
Where does oxidative phosphorylation occur? Describe the starting materials and the end products.
crust -start: 10 NADH, 2 FADH -end: 30-34 ATP
Where does glycolysis occur? Describe the starting materials and the end products.
cytosol -start: glucose (6 carbon) -end: 2 pyruvate, 2 NADH, 2 ATP
Distinguish between depolarization and hyperpolization.
depolarization-cell membrane becomes less polarized/negative relative to the outside solution, which causes gated channels to open allowing Na+ to flow into cell, making the membrane potential more positive (which means the neuron is more likely to fire) hyper polarization-cell membrane becomes more polarized/more negative, K+ moves out of the cell, making cell less likely to fire
Define diploid and haploid. Name the types of cells in humans that are diploid and haploid.
diploid-containing two complete sets of chromosomes, one from each parent (in humans all cells except sex cells are diploid) haploid-having a single set of unpaired chromosomes (in humans sex cells are haploid)
Distinguish between exergonic and endergonic reactions. Give examples of each type.
exergonic-negative free energy change, products have less free energy than reactants therefor free energy is released during product formation (spontaneous) endergonic-positive free energy change requiring
Describe the parts and functions of the human female reproductive system.
genitalia differenziate from the same embryonic tissue as male genitalia; external opening leads to vagina, cervix, and into uterus; sutures has inner glandular lining (endometrium) and outer muscular layer (myometrium) eggs develop in one of two ovaries; typically, one egg released into abdominal cavity; quickly drawn into oviduct or fallopian tube by action of fijmbraie; egg moved down oviduct by cilia; fertilization usually occurs in oviduct; blastocyst is a ball of 32-150 cells that enter uterus oogenesis: -most female mammals are born with all the primary oocytes they will ever have -about 1 million at birth but degeneration leaves about 200,000 in each ovary at puberty -ovarian cycle last approximately 28 days in humans -several oocytes begin maturation but only 1 is ovulated each cycle -menopause: oocytes become deplete and ovulation stops
List the 4 pathways in glucose metabolism.
glycolysis-metabolic pathway that breaks down glucose to pyruvate; breakdown of pyruvate; citric acid cycle-cycle that results in the breakdown of carbohydrates to CO2; also known as the Krebs cycle; oxidative phosphorylation-process during which NADH and FADH2 are oxidized to make more ATP via phosphorylation of ADP
Distinguish between graded potentials and action potentials.
graded-depolarization/hyperpolarization, varies depending on strength of stimulus, occurs locally, spreads a short distance, then dies out action-always the same large amplitude depolarization, all-or-none, actively propagated or regenerative
Describe DNA replication on the lagging strand.
helicase-causes DNA strand separation topoisomerase-relieves coiling in DNA strands ahead of the replication fork primase-make a 10-12 bp complementary primer to DNA polymerase-attaches a nucleotides a nucleotide dNMP to the 3' end of the DNA strand ligase-joins the Okazaki fragments of DNA
What are homologues? What are sister chromatids?
homologues-chromosome that is similar in physical attributes and genetic information to another chromosome with which it pairs during meiosis sister chromatids-pieces of identical DNA that are crucial in the process of cell replication and division
Describe the 5 factors that promote protein folding.
hydrogen bonds-a weak chemical attraction between a partially positive hydrogen atom of a polar molecule and a partially negative atom of another polar molecule ionic bonds- the bond that occurs when a cation binds to an atom hydrophobic effects- refers to molecules that do not have partial charges and therefore are attracted to water molecules; such molecules are composed predominantly of carbon and hydrogen and are relatively insoluble in water Van der Waals forces-attractive forces between molecules in close proximity to each other, caused by the variations in the distribution of electron density with each other disulfide bridge-covalent chemical bond formed between two cysteine residues in a protein; important in the tertiary structure of proteins
Describe hydrogen bonds and their importance in biology.
hydrogen bonds-occurs between molecules that have polar covalent bonds, relatively weak, represented by dashed or dotted lines; are collectively strong (DNA) but are individually weak (substrate and enzyme bonding)
Distinguish between hydrophilic and hydrophobic and amphipathic substances. Give examples of each.
hydrophilic-"water loving", readily dissolves in water; ions and polar molecules; table salt hydrophobic-"water fearing", does not readily dissolve in water, non polar molecule like hydrocarbon; oils amphipathic-have both polar or ionized regions at one or more sites and non polar regions are at other sites; detergent soap
When and where does implantation occur? How does the fetus receive nutrients and exchange gas and waste?
implantation-in humans, implantation occurs within 1-2 weeks of fertilization; blastocyst embed within the uterine endometrium fetus-initially, the embedded blastocyst receives nutrients directly from endometrial glands; shortly after implantation, endometrial (mother) tissue merges with new embryonic (fetus) tissue to form the placenta; portion of the placenta that belongs to the fetus is called the chorion, the chorion's chronic villi-provide a large surface area containing capillaries for the exchange of gas and nutrients/waster
Describe the 3 stages of transcription.
initiation-recognition step of transcription and in bacteria, sigma factor of RNA polymerase recognizes promoter region elongation-RNA polymerase synthesizes the RNA transcript termination-RNA polymerase reaches terminator, which causes it and the newly made RNA transcript to dissociate from the DNA
Using table salt as an example, describe the formation of ions, ionic bonds, and the effect of water on these.
ions in NaCl- sodium loses an electron to become a sodium ion Na+ and chlorine gains an electron to become a chlorine ion Cl-, they then attach to one another to make an ionic bond -Na+: cations, Cl-: anions -with water: ions are hydrophobic so they are capable of dissolving in water
Assuming only water can diffuse across a cell membrane, draw a picture of an animal cell in an 1) isotonic solutions 2) hypertonic solution 3) hypotonic solution.
isotonic solutions- condition in which the solute concentrations on both sides of a plasma membrane are equal, which does not cause a cell to shrink or swell hypertonic solutions- any solution that causes a cell to shrink due to osmosis of water out of the cell hypotonic solutions- any solution that causes a cell to swell when placed in that solution
How is gene expression analogous to a monarchy?
king-DNA genes, messenger-mRNA, blacksmith-ribosome, castle-nucleus, crown-protein
Define learning and memory. Describe how memory was studied in sea slugs.
learning-process by which new information is acquired memory-involves retention of that information over time
Give functions of the medulla, pons, cerebellum, thalamus, hypothalamus, basal nuclei, amygdala, hippocampus and cerebral cortex.
medulla oblongata-coordinates many basic reflexes and bodily functions that maintain the normal homeostatic processes of a person With pons and areas of the midbrain, collectively called the brainstem, control essential functions (breathing, heart rate) cerebellum-responsible for monitoring and coordinating body movementsOverall function of cerebellum to maintain balance and coordinate hand-eye movements pons-serves as relay between cerebellum and other areas of the brain thalamus-Relays sensory information to appropriate parts of the cerebrum and, in turn, sending outputs from the cerebrum to other parts of the brain Receives input from all sensory systems hypothalamus-Production of hormones regulating pituitary gland which regulates hormone secretion from other glands basal nuclei-Involved in planning and learning movements Involved in initiating or inhibiting movements Affected in Parkinson disease amygdala-understand and remember emotional situations, recognize emotional expressions in others hippocampus-establish memories for spatial locations, facts, and sequences of events, produce new neurons cerebral cortex-Thin, surface layer of gray matter on the cerebrum Sensory and motor information integrated Initiation of voluntary acts, generation of speech, learning, memory, and production of emotions
List the semiautonomous organelles. Why are they called this?
mitochondria and chloroplast; organelles grow and divide, but they are not completely autonomous because they depend on other parts of the cell for their internal components
Where does the citric cycle occur? Describe the starting materials and the end products.
mitochondrial matrix -start: 2 acetyl (two 2 carbons) -end: 6 NADH, 2 FADH, 4 CO2, 2 ATP
Where does the breakdown of pyruvate occur? Describe the starting materials and the end products.
mitochondrial matrix -start: 2 pyruvate (two 3 carbon) -end: 2 CO2, 2 acetyl, 2 NADH
Distinguish between monosaccharides, disaccharides, and polysaccharides. Give examples of each.
monosaccharides-single sugars, most common are 5 or 6 carbons, can be linear or in a ring -pentoses: ribose and deoxyribose, hexoses: glucose disaccharides-carbohydrates composed of two monosaccharides, joined by dehydration and broken apart by hydrolysis -sucrose, maltose, lactose polysaccharides-many monosaccharides linked together to form long polymers -energy storage: starch and glycogen; structural role: cellulose, chitin and glycosaminoglycans
Draw a neuron and label its parts. Give the function of each part.
neuron-highly specialized cell found in nervous systems of animals that communicates with other cells by electrical or chemical signals cell body-contains two types of extensions or projections that arise from it: axons and dendrites dendrites- may be single projections of the cell body but more commonly are elaborate treelike structures with numerous branching extensions that provide a large surface area for contacts with other neurons axon-extension of the cell body that transmits signals along its length and eventually to neighboring cells axon hillock- part of the axon closest to the cell axon terminals-convey electrical or chemical messages to other cells, such as other neurons or muscle cells glia-cells that surround neurons and perform numerous roles myelin sheath-specialized glial cells war around the axons at regular intervals to form this insulating layer nodes of Ranvier-sheath is periodically interrupted by these non insulated gaps oligodendrocytes-brain and spinal cord, the myelin-producing these glial cells Schwann cells-glial cells that form myelin on axons that travel outside the brain and spinal
Describe the structure of DNA. Include nucleotides, phosphodiester bonds, backbone, base pairing, hydrogen bonding, complementary and antiparallel in your description.
nucleotides-building blocks of DNA (and RNA) phosphodiester bonds-bond that holds a phosphate group linking 2 sugars backbone-where bases project from (sugar and phosphate group) base pairing-complementary (AT & GC) 5' to 3'-antiparallel
Define nucleus, ganglion, tract, nerve, cranial nerves, spinal nerves, white matter and gray matter.
nucleus-cell bodies of neurons involved in a similar function in the CNS ganglion-similar structure in PNS tract-myelinated axons that run in parallel bundles in the CNS nerves-similar structure in PNS cranial nerves-connected directly to the brain spinal nerves-connections between the PNS and spinal cord white matter-myelinated axons grouped together gray matter-neuronal cell bodies, dendrites and some unmyelinated axons (forms dorsal horns-connects to dorsal root, part of spinal cord, incoming information; and central horns-connects to ventral root, part of spinal nerve, outgoing information
What is the octet rule? How is it significant?
octet rule-most elements are stable with 8 electrons in their outer shell (hydrogen=2) -applies to the elements that are common in living things (C, N, O, P, S) which form bonds with other elements in order to become stable
What is an organic molecule? What's special about carbon?
organic molecules-contain carbon and are abundant in living organisms -carbon can form up to 4 bonds (single or double) and can form both non polar and polar bonds (polar: H and C; non polar: N and C, O and C)
How are the phospholipids arranged in the plasma membrane? Why?
phospholipids are amphipathic which means they have a hydrophobic tail and hydrophilic head; they are arranged to where the heads are facing the outside (near water) and tails are touching each other on the inside (away from water) -hydrophilic head (water loving) near water and hydrophobic tails (water fearing) away from water
Explain the difference between polar and non polar covalent bonds and the role of electronegativity in each.
polar-have different electronegativities, occur because the distribution of electrons creates a differences in charges (polarity), has an unequal pull non polar-have same electronegativity, has an equal pull
Explain the 5 phases of mitosis.
prophase-nucleus membrane dissociates sister chromatids condense and get sick together prometaphase-mitotic spindle completely forms centrosomes move to opposite poles; spindle fibers interact with sister chromatids and the nuclear envelope disappears; kinetochore microtubules connect to the centromeres metaphase-sister chromatids are lined up in the middle of the poles and organized into a single row anaphase-pairs of chromatids split apart at centrosomes; kinetochore microtubules shorten and separate copies of chromosomes get pulled toward opposite poles telophase-chromosomes reach their wanted pole; nuclear envelops reform and mitotic spindle disappears cytokinesis-cytoplasm divides and two nuclei are segregated into separate daughter cells
Fine redox, reduction, and oxidation. Give an example of a redox reaction.
redox-when an atom or molecules is oxidative electron that is removed must be transferred to another atom or molecule reduction-addition of electrons to an atom or molecule oxidation-remove of one or more electrons from an atom or molecule
List factors that affect the function of enzymes and explain what each factor does.
reversible inhibitors, irreversible inhibitors, prosthetic group, cofactors, coenzymes -most enzymes function maximally in a narrow range of temperature and pH, outside this range the enzyme function decreases
Compare and contrast the 2 kinds of ER.
rough-studded with ribosome; sorts proteins that are destined for ER, Golgi, lysosomes, vacuoles, plasma membrane, or outside the cell; proteins are packaged into membrane vesicles and moved from one location in endomembrane system to another; insertion of certain newly made proteins into the ER membrane; attachment or carbs to proteins and lipids (glycosylation) smooth-lacks ribosomes; functions in diverse metabolic processes; provides an increased surface area for enzymes that play important metabolic roles; detoxify many potentially harmful organic molecules (liver); carbohydrate metabolism, store energy in the form of glycogen (polymer of glucose); accumulation of calcium ions, contains Ca pumps; critical in synthesis and modification of lipids; enzymes in smooth ER are necessary for certain modifications of lipids cholesterol that are needed to produce steroid hormones (estrogen and testosterone)
Distinguish between saturated and unsaturated fatty acids.
saturated-all carbon are linked by single covalent bonds, solid at room temperature unsaturated-contain 1 or more double bonds, liquid at room temperature
What is a test cross? Give an example.
when a unknown dominant trait is crossed with a homozygous recessive trait to determine its genotype
