UWORLD B/B
PCR
used to amplify DNA; heat to separate strands; then cool so primers attach; repeat
ELISA
used to find concentration of molecule of interest in a sample; uses antibodies
cell cycle: G1
the first of four phases of the cell cycle that takes place in eukaryotic cell division. In this part of interphase, the cell synthesizes mRNA and proteins in preparation for subsequent steps leading to mitosis. G1 phase ends when the cell moves into the S phase of interphase
the plural cavity
the thin fluid-filled space between the two pulmonary pleurae (known as visceral and parietal) of each lung. A pleura is a serous membrane which folds back onto itself to form a two-layered membranous pleural sac.
bacterial conjugation
the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells, often via a pilus.
enveloped viruses
these viruses are more susceptible to changes in environmental conditions
Left ventricle has ___ walls
thicker walls tp pump blood at higher pressure to all body tissues except lungs
How to calculate the molecular weight of a protein:
(# of AAs in the protein) x (average molecular weight of an AA (110Da))
NMR = Magnetic field + Radio waves = α spin to β spin state = H splits
(NMR) spectroscopy detects spinning H atoms by exposing them to radio waves that excite atoms from the α spin to the β spin state. The position of a hydrogen peak in an NMR spectrum is referred to as the chemical shift, and it represents the frequency of Beff. Chemically equivalent Hs are represented as single peaks on the NMR spectrum. eg - chloroform has one H and three Cl atoms attached to a central carbon. The hydrogen atom is not equivalent to any other atoms within the structure and will be represented as a single peak on the NMR spectrum. Methanol, ethanol, and ethyl acetate have one, two, and three sets of equivalent protons, respectively.
Slow-twitch muscle fibers have ____ mitochondria
A lot
Goal of 5'cap and Poly A tail
5'cap - recognized by ribosome during translation and prevents degradation Poly A tail - The chain of adenosine nucleotides prevents degradation and facilitates export of mature mRNA from nucleus to cytoplasm
Difference between Stabilizing, disruptive and Directional Selection
Stabilizing = Average phenotypes; ↓diversity Disruptive= Both Extremes phenotypes Directional= 1 Extreme phenotypes; ↓diversity
Emulsification
Start of lipid processing, begins in small intestine *duodenum*, bile salts breakdown lipids -> smaller droplets
Memory & Effector/Plasma cells
Memory cell (future) = Remember antigens next time Effector/Plasma cells (now) = Antibody factory that synthesize & secrete them during attack (The killers)
What antibodies does blood type AB have?
NONE (*universal recipient*)
3200-3600
OH groups; broad peak
How many antigens can bind one antibody?
ONE! specificity determined by unique AA structure on variable region
Western blot (protein immunoblotting)
Protein separation and identification technique that uses labeled antibodies to detect specific proteins after gel electrophoresis
Transcription factors
Proteins that can upregulate(activators) by facilitating binding of the RNA pol or down-regulate(repressors) by preventing the binding of the RNA pol to the promoter region
Chaperons
Proteins that help other proteins fold correctly; decrease tendency of aggregation and increaes solubility
oncogenes
Proto-oncogenes are genes that normally help cells grow. When a proto-oncogene mutates (changes) or there are too many copies of it, it becomes a "bad" gene that can become permanently turned on or activated when it is not supposed to be. When this happens, the cell grows out of control, which can lead to cancer.
function of insulin
made by the pancreas that allows your body to use sugar (glucose) from carbohydrates in the food that you eat for energy or to store glucose for future use. Insulin helps keeps your blood sugar level from getting too high (hyperglycemia) or too low (hypoglycemia)
Hair growth
made of dead keratinized cells & produced in hair follicles
What is the name of the mature gamete of - males - females?
males: spermatozoa / spermatazoon females: ovum
DNA of telomeres are ____
noncoding and highly repetitive
Antibodies bind epitopes through ____ interactions
noncovalent (i.e. H+ bonding or electrostatic)
vasoconstriction will
restrict blood flow / increase blood pressure
Dynein
retrograde transport- distal site to nucleus
RP HPLC
reversed phase; used non polar stationary phase and polar mobile phase
ghrelin
secreted by gastric cells in stomach
leptin
secreted by white adipose tissue
if genes for RNA are located extrachromosomally, it's implied they are
self-replicating
Ion-Exchange Chromatography
separates based on net charge; if cation exchange, negative molecules will elute sooner and vice versa
Vagine
sexual organ through which sperm enters uterus
Conjugation:
the exchange of genetic information between prokaryotes, typically in the form of plasmid DNA. It does not occur in eukaryotes.
Audioradiography
used to image radiolabeled atoms; these atoms convert silver halide crystals to metallic silver producing an image
Immunoprecipitation
used to purify proteins from a solution; bind an antibody with bead to protein of interest, then can precipitate out
how does vasodilation impact the rate of bloodflow to the skin?
vasodilation increases the rate of bloodflow, allowing the heat from blood to be released/radiated into the environment.
Bone is what kind of tissue?
Connective tissue
Right ventricle has ___ walls
thinner walls to pump blood at lower pressure to lungs
AA with ionizable side groups have how many pKa values?
three pKa values
Diff btw Prok & Euk secretory pathway
Prok secretory pathway - Lack membrane bound organelles; ∴ utilize special channels in plasma membrane to secrete proteins Euk secretory pathway - Have membrane bound organelles; ∴ utilize Rough ER and Golgi body to secrete proteins
Directional selection
1 extreme phenotype favored over all others b/c of additional fitness it confers
Molecular weight of deoxyribonucleoside monophosphate in decreasing order:
1. deoxyguanosine 2. deoxyadenosine 3. deoxythymidine 4. deoxycytidine
palmitic acid
16:0, the only free fatty acid synthesized by cells
mRNA transcript is read in what direction?
3' to 5' direction
Meiosis produces
4 haploid cells
4) Ependymal cells https://www.khanacademy.org/test-prep/mcat/organ-systems/neural-cells/v/ependymal-cells
4) Ependymal cells = create barriers - are epithelial cells that line the compartments of the CNS and - secrete CSF - arise from ectoderm
species
A group of organisms having many characteristics in common and ranking below a genus. Organisms that reproduce sexually and belong to the same species interbreed and produce fertile offspring.
ADH
ADH - is released by the posterior pituitary when BP falls or when blood osmolarity rises. ADH promotes water reabsorption by increasing the permeability of the DCT and collecting duct to water. ADH also induces vasoconstriction, the narrowing of blood vessels. Both of these effects increase BP
distal tubule
ADH and aldosterone promote the reabsorption of water in this segment of the tubule
Adrenal hormones (Adrenal Medulla)
Adrenal medulla - Norepinephrine and epinephrine - function to mobilize the body under extreme stress and - promote rapid information processing in part by maximizing blood flow to organs essential for survival. - They achieve this effect by promoting the following changes in blood vessel diameter that lead to altered blood pressure:
Aldosterone
Aldosterone - is released in response to RAS activation or to an increased serum level of K+ (↓Na+) Aldosterone acts on the DCT and collecting ducts of nephrons to - promote the reabsorption of Na+ and the secretion of K+. Increased reabsorption of Na+ - increases the osmolarity, or solute concentration, of the renal interstitial fluid. Elevated osmolarity promotes - water reabsorption, which ultimately causes blood volume and BP to increase
fat structure
All fats are derivatives of fatty acids and glycerol. Most fats are glycerides, particularly triglycerides (triesters of glycerol).
Lipid processing during digestion
All lipids emulsified, and triglycerids/phospholipids are hydrolyzed
Difference btw Alternate Splicing & Gene Duplication & *Epigenetic modification* - what generates what? - eg
Alternate Splicing - *Several proteins* are generated from *a single pre-mRNA transcript* - eg- during splicing Gene Duplication = Evolutionarily related genes - *Several proteins* are generated from *multiple similar genes or single gene* - Due to unequal crossing over - overtime they can carry out distinct roles at different times during life cycle Epigenetic modification = No change in sequence - eg - Methylation and demethylation - *one protein sequences* generate *several different gene expressions* - leads to alternative gene expression without changes in the sequence of the nucleic acid itself.
What is the main site of gas exchange?
Alveoli
autosomal recessive
An autosomal recessive disorder means two copies of an abnormal gene must be present in order for the disease or trait to develop. The parents are often fine
Anaphase I vs II
Anaphase I: *homologous chromosomes separate*, but sister chromatids together Anaphase II: *sister chromatids separate*
Angiotensin 2 ultimately raises BP
Angiotensin 2 ultimately raises BP by 1) induces the adrenal cortex (on kidney) to release *Aldosterone* --> Jobs: Water retention in kidney 2) causes posterior pituitary to release *ADH* --> Job 1: Water retention in kidney --> Job 2:constrict the arterioles(↑resistance) 2 Main Goal; 1. Water retention in kidney --> will ↑BP by increasing blood volume 2. constrict the arterioles (↑resistance) --> will ↑BP without increasing blood volume
Animal cell plasma membranes contain; (4)
Animal cell plasma membranes contain; - phospholipids, - cholesterol, - glycolipids (lipids + sugar groups), - glycoproteins (proteins + sugar groups - carbohydrates - transmembered protein - integral protein
Cells of the immune system
B-cells: Identifying foreign pathogens, antigen presenting & producing antibodies T-cells: Mediating a number of immune responses, including those against viruses, bacteria & parasites Dendritic cells: Identifying foreign pathogens, antigen presenting & activating other immune cells Macrophages: Degrading pathogens & dead body cells via phagocytosis Basophils: Releasing chemical mediators, such as histamine, that enhance an immune response Mast cells: Releasing chemical mediators, such as histamine, that modulate allergic reactions Neutrophils: Killing & phagocytosing bacterial cells Eosinophils: Defending against parasitic infections & modulating immune responses during allergic reactions NK cells: Releasing toxins to destroy virus-infected body cells
Endosomal pathway
Begins at endocytosis. Following internalization of extracellular material into vesicles, the vesicles containing these materials will mature to early endosomes-->late endosomes-->lysosomes. Lysosomes are membrane enclosed organelles responsible for digestion in the cell. It contains an acidic environment and hydrolytic enzymes that facilitate the degradation of biomolecules. endolytic cargo that does not undergo retrograde trafficking and fails to escape from endosomes will typically end up at the lysosomes
Allosteric effectors
Bind proteins at one site and induce a conformational change at another site
1st step of Transcript
Binding of TF factors and RNA polymerase II to TATA box in promoter region of DNA
G0 phase
Cell cycle arrest; resting phase
Chemical digestion of Lipids
Chemical digestion = cleavage of chemical bonds within macronutrients to form simpler compounds that can be absorbed - is carried out by acids and enzymes eg - Pancreatic Lipase hydrolyzes triglycerides within micelles into free FAs & monoglycerides - Lingual lipase - Salivary amylase hydrolyzes (chemically digests) the polysaccharide starch into the disaccharide maltose.
Endonucleases
Cleave mispaired nucleotides and adjacent nucleotides
sequences of the pathway of communication between neurons?
Communication between neurons involves an electrochemical process - electric signals → chemical signals, and vice versa. dendrites (pre-synaptic neuron) → soma → axon → synapse → dendrites (post-synaptic neuron)
Common steroid hormones
Cortisol, aldosterone,e strogen, testosterone, progestrone
If a cell's membrane potential changes from -60mV to -70mV after treatment with a drug, the drug receptor is most likely linked to A) a G-protein B) adenylate cyclase C) a sodium channel D) a potassium channel
D) a potassium channel -60mV to -70mV means the cell is repolarizing, which is accomplished by K⁺ channels
The genetic code is said to be degenerate because there are 64 different codons, but translation produces only 20 unique amino acids. The degeneracy of the genetic code is due to which mechanism? A.Exclusion of protein coding regions from mature mRNA B.Errors during tRNA charging C.Ambiguity of the tRNA for the amino acid D.Nontraditional base pairing of the anticodon with the third base of the codon
D.Nontraditional base pairing of the anticodon with the third base of the codon *This hypothesis states that the first two nucleotides on the mRNA codon require traditional (Watson-Crick) base pairing with their complementary nucleotides on the tRNA anticodon, but third nucleotide on the codon may undergo less stringent ("wobble") base pairing in a non-Watson-Crick manner. *Codon degeneracy is explained by nontraditional base pairing at the third position of the codon and anticodon.
Difference between DNA Polymerase and RNA Polymerase I, II and III - which can proofread and which cannot - which transcribe mRNA, rRNA, tRNA, snRNA, miRNA what or duplicate what? - what do they have to do for transcription or translation to be initiated?
DNA Polymerase = replication of *DNA* - can proofread Euks have 3 diff RNA polymerases (RNAPs) RNA polymerase I = transcription of *rRNA* RNA Polymerase II = transcription of *mRNA, snRNA, miRNA* - CANNOT proofread - Must bind to DNA at a promoter region for transcription to be initiated RNA polymerase III = transcription of *tRNA* - tRNA must bind to large ribosome for AA translation to be initiated
DNA helicase
DNA helicase - unwinds the DNA double helix and separates the parent strands at the origin of replication.
Factors affecting thermodynamic stability of DNA:
DNA length (longer= more time to melt/reanneal), pH, Salt concentration (ionic strength)
DNA ligase
DNA ligase - joins Okazaki fragments.
Complete removal of ovaries would most likely result in...?
Degeneration of breast tissue
Mass of phospholipids
Depends on backbones- either glycerol w/2 FA tails or *sphongine* with 1 FA
How is Ca2+ release induced in skeletal muscle cell?
Depolarizing current (AP) runs along sarcolemma and travels down the T tubules -> SR opens Ca2+ channels
Which cell-cell junction helps skin cells withstand mechanical stress by directly anchoring intermediate filaments of adjacent cells?
Desmosomes
Northern blot
Detects particular sequence of *RNA*
Southern Blot
Detects particular sequence of DNA
What 3 things happen during normal inspiraion of lungs?
Diaphragm contracts, intrapleural pressure reduced, elevation of rib cage
Diff btw homodimer and heterodimer - what is dimer? - how are they bound together?
Dimer = 2 Monomers = 2 non-covalently bound polypeptide chains homodimer - the polypeptide chains of the 2 monomers have the same sequence heterodimer - the polypeptide chains of the 2 monomers have the diff sequences
Disruptive selection = both extremes
Disruptive selection - results in the selection of 2 extreme phenotypes that differ from the average. - the average phenotype is selected against while 2 extreme phenotypes are selected for.
dNTPs and matureRNA - what joins them? - what attacks what? - exergonic rxn? - what is released? - endergonic rxn? - what bond is formed
During replication - DNA poly joins uncoupled dNTP to the new DNA strand 1) 3'OH from the last nucleotide of growing strand attacks 5'P of an incoming dNTP 2) 2 PPi is cleaved off the dNTP *(exergonic)* -> results in release of H₂O + PPi + Energy 3) PPi is further cleaved into mono(P) to release more energy 4) Energy released is used to form a covalent phosphodiester bond btw the last nucleotide of the growing strand and the incoming dNTP *(endergonic)*
How is a Neural tube & Neural crest formed? - what is neurulation - what happens after gastulation? steps ... Neural tube is precursor of Neural crest precursor of
Ectoderm → Neural plate →Neural groove →Neural tube + Neural crest Neurulation - Formation of the nervous system in vertebrates Following gastulation - the notochord releases signals nagging the ectoderm to thicken & form the neural plate - Neural plate fold inward→form Neural groove - Neural folds converge → create Neural tube Neural tube (precursor of CNS) pinches off ectoderm Neural crest (precursor of PNS) migrate away to give rise to most of the PNS
https://www.khanacademy.org/test-prep/mcat/organ-systems/biological-basis-of-behavior-the-nervous-system/v/structure-of-the-nervous-system
Educational objective: The nervous system can be divided into two major branches, the central and peripheral nervous systems. The peripheral nervous system can be further divided into the sensory (afferent) and motor (efferent) divisions, with the motor division being composed of the somatic and autonomic nervous systems. Furthermore, the autonomic nervous system is divided into the parasympathetic and sympathetic branches.
D-mannose and D-glucose are ____
Epimers, differ at only ONE stereocenter
*Convergent Evolution*
Evolution toward *similar* characteristics in *unrelated* species
phagocytosis, receptor-mediated endocytosis, pinocytosis
Examples of methods of endocytosis:
Conjugation
Exchange of genetic info b/w prokaryotes, often in form of *plasmid DNA*
Knockout Model
Existing gene is repalced or disrupted -> absence of protein product
Expressivity (genetics)
Expressivity is the degree to which trait expression differs among individuals. Unlike penetrance, expressivity describes individual variability, not statistical variability among a population of genotypes.
Repeated generational inbreeding will to _____
Extinction of species
Fast-twitch fibers
Faster racontraction rates, hydrolyze ATP faster
Ovaries
Female gonads; produce gametes (oocytes) and secrete emale ex hormones
X-linked recessive disorders
Females (XX) express phenotype when *both* X chromosomes have allele; but males (XY) need only *single copy*
IR Absorption Range
Fingerprint region (600 - 1400cm⁻¹) C - C C - O C - N Double bonds (1600 - 1800cm⁻¹) C = C C = O C = N Triple bonds (2100 - 2400cm⁻¹) C ≡ C C ≡ N Single bond (2700 - 3500cm⁻¹) H - C H - O H - N
IR Spectrum Functional Groups
Functional groups show absorption in the infrared spectrum at different frequencies depending on the bond type present in the particular functional group. Characteristic functional group absorptions include 3650-3200 cm−1 (alcohol and phenol O−H stretch); 3550-3060 cm−1 (amide N-H stretch); 3100 cm−1 (sp2 C=H stretch); 3000-2875 cm−1 (sp3 C-H stretch); 2260-2,100 cm−1 (sp C≡H stretch); and 1850-1650 cm−1 (C=O stretch). fingerprint region (700-1500 cm−1)
Non-native conformations of proteins
Forced to expose more hydrophobic residues to the aqueous environment; tend to aggregate
Ketone bodies
Fuels ources that're made under *low* glucose conditioned; derived from acetyl-CoA
- Stomach cell type (4) - What do they secrete? - Function of secretory product
G cells - secrete Gastrin - Signals parietal cells to secrete HCl Parietal cells 1) secrete HCl - Primary component of gastric juice; activates proteolytic enzymes, kills microbes & denatures (unfolds) proteins 2) secrete Intrinsic factor - Aid in the absorption of vitamin B12 in ileum Chief cells 1) secrete Pepsinogen - Zymogen (inactive form) of pepsin, cleaves polypeptides into smaller peptides when activated by the low pH of gastric juice 2) Gastric lipase - breaksdown lipids in the stomach Mucous cells - secrete Mucus & bicarbonate - Protect stomach walls from autodigestion by gastric juice, which contains acid & proteases
Gas-liquid chromatography (GC)
Gas-liquid chromatography (GC) separates molecules based of boiling point. - a mobile phase = gas - stationary phase = liquid column B.pt of molecules can be determined based on - intermolecular forces - more H- bond = higher Int. forces - less branching = higher Int. forces - molecular weight - higher MW = higher B.pt A higher MW indicates a higher boiling point and longer retention time because molecules with larger MWs have larger surface areas, giving a greater extent of Van der Waals forces between the molecules.
Histone acetylation promotes ____
Gene transcription, *loosens heterochromatin-> euchromatin*, making DNA region readily accessible
- Gluconeogenesis - Glycogenolysis - Glycogenesis
Gluconeogenesis =Glucose + new + synthesis - synthesis of glucose from other molecules - promoted by glucagon → to ↑glucose Glycogenolysis = Glycogen + breakdown - breakdown of glycogen into glucose - promoted by glucagon + Epi + NorEpi -Glycogenesis = Glycogen + synthesis - synthesis of glycogen (stores glucose) - promoted by insulin → to ↓glucose
Gln
Glutamine (Q)
Starvation leads to what body responses?
Glycogen stores used, then triacylglycerols (storage lipids); accumulated acetyl-CoA converted into ketone bodies
Compared to blood in pulmonary veins, pulmonary arteries blood has HIGHER concentrations of.....?
H+ and CO2 b/c pulmonary artery= carries *deoxygenated blood* from heart -> lungs
When hydrophobic residues exposed to water, what happens?
H20 molecules forced to form rigid network to satisfy H+ bond requirements; thermodynamically unfaborable
Euchromatin is marked by:
HIGH levels of histone acetylation andLOW levels of DNA methylation
Egg and sperm cells are _____ cells
Haploid- contribute *EQUAL* number of chromosomes to zygote during fertilization
A scientist proposed that ectopic endometrial cells contain extra copies of the VEGF gene. Given this information, which of the following techniques can be used to analyze VEGF gene count? I. DNA sequencing II. Northern blot III. Southern blot "... An enzyme-linked immunosorbent assay (ELISA) was used to characterize the concentration of VEGF protein present within these samples..."
I, III. DNA sequencing, Southern blot -Southern blot: detect a particular sequence of DNA
IMMUNE SYSTEM
IMMUNOLOGY SYSTEM
phospholipids, cholesterol, glycoproteins, glycolipids
Important components of the libipid bilayer (fluid mosaic model)
General overview of cellular respiration - Pyruvate → - main electron carriers for ETC - ETC location in Euks and Proks - How does ATP synthase generate ATP from ADP+Pi - Is ATP synthase active in Proks and Euks under anaerobic conditions? - why or why not?
In Euks Cellular respiration continues when pyruvate is imported into the mitochondria & converted to --> Acetyl CoA Acetyl CoA enters the kreb cycle to generate the necessary electron carriers (NADH + FADH₂) for ETC ETC pumps H⁺ across Inner Mit Membrane; generating a proton gradient --> with O₂ as final electron acceptor ATP synthase - Uses energy of ETC proton gradient to generate ATP from ADP+Pi - Does not directly need O₂ to generate ATP BUT ... The proton gradient by which it function is O₂ dependent in Euks In Proks - No mitochondria - ETC is located on plasma membrane ∴ Under anaerobic conditions, ATP synthase is not active in Euks, but is active in Proks because there is not proton gradient required
anaphase I, anaphase II
In the absence of recombination, maternal and paternal alleles are separated from each other during ________, and identical alleles on each sister chromatid are separated from each other during ______
Resting state of Muscle contraction
In absence of Ca2+, tropomyosin *blocks* myosin-binding sites of actin filament
How does insulin respond to low blood glucose levels?
In response to high serum glucose concentration, - β cells in the pancreas release insulin Insulin promotes the uptake of glucose by fat, liver, and skeletal muscle cells. Insulin also promotes glycogenesis, the synthesis of the glucose storage molecule glycogen. Overall, insulin decreases blood glucose concentration by promoting the cellular uptake and storage of glucose.
Inductive signaling
Inducer (signaling cell) releases chemical signals that act on competent neighboring cells by regulating expression of specific genes needed for cell determination
Simple distillation
Is best suited for compounds with boiling points between 25°C and 150°C an ice bath is used in the receiving flask - to *prevent the distillate from evaporating*
Angiotensinogen
Is made in the liver - It is released into the blood stream, but is not active .. - It is sort of a sleep walker - Until it meets renin - which chops up a big chunk - converting it to angiotensin 1
Difference btw insulin sensitive & insulin resistant
Insulin-sensitivity - organism need only a minimal amount of insulin to induce an appropriate reduction in glucose levels. insulin-resistant - organism need substantially more insulin to take up the same amount of glucose.
Cytoskeleton
Intracellular scaffolding that is composed of three types of fibers: microfilaments, intermediate filaments, and microtubules. Organize cellular compartment, support motility(movement and intracellular transport), and structural integrity. Microtubules: Kinesin: moves intracellular cargo along the microtubules away from nucleus Dynein: moves intracellular cargo along the microtubules toward the nucleus
Isoelectric focusing
Isoelectric focusing - uses a stable pH gradient to separate proteins based on their isoelectric point.
DNA ligase
Joins Okazaki fragments
During prolonged starvation, acetyl-CoA from FA oxidation is converted to ____
Ketone bodies (alternative fuel molecules); process happens in mitochondria
What organ produces erythropoietin?
Kidney
Intracellular Fluid (ICF) contain higher concentration of Extracellular Fluid (ECF) contain higher concentration of If the intracellular [Na+] is low? what happens? If the extracellular [Na+] is low? what happens?
K⁺, Mg²⁺ and Proteins Na⁺, HCO₃⁻, Cl⁻, PO₄³⁻ If the intracellular [Na+] is low? -Na⁺ will be released into cell by carrier protein If the extracellular [Na+] is low? - glucose will bind to symport on extracellular side of cell membrane and be transported into the cytosol
Function of Endothelial Cells
Line the surface of blood vessels
Metaphase I and II
Metaphase is the phase in which chromosomes align in the middle of the cell on the metaphase plate. Mitosis Meta-Sister chromatids align (diploid) Metaphase I - Homo Chromosomes align Metaphase II - Sister chromatids align (haploid)
receptor-mediated endocytosis
Method of entry for non-enveloped (naked) viruses?
Mitochondria - function - Example of tissues that require ATP from Mit - Unique cell that does not have Mit
Mitochondria - allow cell to utilize O₂ in ETC to generate ATP - ∴ Mit defects affect mit active tissue like neurons, muscles, heart, kidney 1) Hepatocytes (liver) → need ATP for carb, protein & lipid synthesis 2) Neurons (nervous system → need ATP for transmission of signals via synapses 3) Myocytes (muscles) → need ATP for contraction & movement RBCs don't have Mitochondria
CO2+H2O⇋H2CO3⇋HCO−3+H+ The patient is noted to have decreased pulmonary gas exchange. Given this, which of the following is most likely to occur in the patient's blood if this condition is left untreated?
More H2CO3 will be produced and blood pH will decrease.
What happens during Cross-bridge formation (muscle contraction)?
Myosin head binds to myosin-binding site
Describe the "power stroke" of muscle contraction
Myosin head pulls actin filament to *center* of carcomere
Natural selection
Natural selection - is an evolutionary mechanism by which only beneficial alleles are selected for while unfavorable traits are selected against. These selected changes alter the population's allele frequencies, which improves the species' fitness. Consequently, these populations have an improved probability for survival rather than an increased probability for extinction.
Can Northern blot be used to determine relative gene count?
No
*Divergent evolution*
Occurs when 2 species descended from recent COMMON ancestor inhabit *contrasting* environments & evolve *distinct* traits->> better adapt
Helper T cell function for B lymphocyte
Promotes activation/proliferation; induces differentiation, antibody-secreting plasma cells & memory cells
Helper T cell function for Cytotoxic T cell
Promotes cytotoxic T cell activation and proliferation
Positive control (+) and Negative control (-)
POMK + - + + - + FUKU + + - + + - Positive control (+) - help ensure that each step of the experimental procedure performs as expected. - The first lane in each autoradiogram is also a positive control, showing that radiolabels are added when all enzymes are present.(+,+) Negative control (-) - shows what the outcome would look like if the results were negative and helps confirm that positive results come from the expected source. -- In this case, the lane with no POMK in the 32P experiment and the lane with no fukutin in the 3H experiment are negative controls because it is expected that the radiolabels will not be added when the relevant enzymes are absent.
Gastrulation
POST-implantation process by which embryo progresses from blastula to gastrula stage
Terpenes
Precursors in synthesis of cholesterol & steroid hormones
G1 phase
Presynthetic growth, organelle duplication
Primase
Primase - synthesizes RNA primers and positions them at the beginning of each DNA strand. Only one primer is needed for leading strand synthesis, but lagging strand synthesis requires many RNA primers.
Alternative splicing:
Produces multiple protein products from the same gene
Total activity of protein
Product of total protein x specific activity
Structure of Adenine
Purine (2 rings)
Genome replication occurs during which phase of cell cycle?
S phase
Reducing SDS-PAGE
SDS-PAGE under reducing conditions (so breaks disulfide bonds); separates completely denatured proteins on mass alone
The separation of enantiomers
Separation of enantiomers relies on changing the physical properties of the molecules. The separation of enantiomers, - requires the *addition of a resolving agent (a chiral molecule) to a racemic mixture* - The resolving agent reacts with each enantiomer, forming a covalent bond or an ionic salt. - Because the resolving agent is chiral, it incorporates a new chiral center into each enantiomer, --> changing their physical properties & --> creating a pair of diastereomers. - *The resolving agent is removed once the diastereomers are separated to yield the original molecules as single enantiomers*.
What AA can be phosphorylated?
Serine, threonine, tyrosine (due to -OH *hydroxyl* groups in R group)
Open reading frame (ORF)
Set of codons within a strand of mRNA that can be translated by a ribosome
Origin of Replication (ori) in Prokaryotes
Single Ori, circular DNA
Single-strand DNA-binding protein
Single-strand DNA-binding protein - binds to each strand to prevent spontaneous reannealing of unwound single-stranded DNA.
Speciation = New species
Speciation - is the evolutionary process of forming a new species from a previously existing species. This process occurs over many generations and results in organisms that cannot interbreed with the ancestral species. Although the subgroup of cheetahs developed different characteristics, it retained the ability to mate with Namibian cheetahs and is therefore not considered a separate species.
Most common nonreducing sugar?
Sucrose
Primase
Synthesizes RNA primers and positions them at start of each DNA strand
DNA polymerase
Synthesizes daughter strands in 5'->3' direction only
Blood pressure is written
Systolic over Diastolic
helper T cells
T cells that help the immune system by increasing the activity of killer cells and stimulating the suppressor T cells
Telomeres and Centromeres = Heterochromatin regions
Telomeres are regions at chromosomal ends that are repeatedly truncated with each round of cell division. Centromeres join two sister chromatids and are required for proper chromosome division during mitosis. Despite their different chromosomal locations, both telomeres and centromeres are composed of heterochromatin, a tightly condensed complex of DNA wrapped around histones. Because of its structurally restrictive form, heterochromatin is transcriptionally inactive, meaning that proteins responsible for regulating gene expression cannot access the tightly packed DNA. As a result, hetechromatic regions are often gene-poor and contain repetitive DNA.
5'-TTAGGG-3'
Telomeres contain highly repetitive DNA with the repeated sequence being:
What is the present-day understanding of human differentiation?
The Regulative Hypothesis - each embryonic cell receives a complete set of genes - cell position helps determine differentiation
The blood-brain barrier
The blood-brain barrier - is composed of endothelial cells held together by tight junctions, which limit paracellular transport. Carrier-mediated transport allows the passage of glucose, amino acids, and nucleosides into the CSF. Small, lipophilic molecules pass easily into the CSF through transcellular diffusion.
What is the blood brain barrier composed of? what are they held by? why? What can pass through to the CSF? mode of transport
The blood-brain barrier - is composed of endothelial cells held together by tight junctions, which limit paracellular transport. - Glucose, AAs, and Nucleosides enter the CSF visa carrier-mediated transport - Small, lipophilic molecules pass easily into the CSF via transcellular diffusion.
https://www.khanacademy.org/test-prep/mcat/organ-systems/neural-synapses/v/synapse-structure
The electric signal from the axon of the pre-synaptic neuron is converted to the release of neurotransmitters into the synaptic cleft between neurons. Neurotransmitters then bind to receptors on post-synaptic dendrites, changing the electric potential of the cell.
The founder effect
The founder effect = small initial pop with lots of abnormal allele that gets passed on to future generations - abnormal abundance of an allele in a population derived from a small initial population. - If, by chance, the initial population had an abnormal abundance of a certain allele, this abnormality will generally persist for future generations.
the lumen
The hollow space enclosed by the walls of the Gastrointestinal Tract
In the heart, atrial depolarization occurs because?
The influx of *positive* ions (Na+, Ca2+) into SA and AV nodal cells, generating APs
Large Intestine
The large intestine is composed of three subdivisions: the cecum, colon, and rectum. The colon functions to absorb electrolytes (eg, sodium, chloride) and additional water from the mass of undigested material. As water is absorbed by the colon, the undigested material concentrates into feces (waste matter), which is stored in the rectum for subsequent excretion. Educational objective: The colonic segment of the large intestine functions to absorb water and electrolytes from undigested waste material that is left over from digestion and absorption in the small intestine.
germ cells
a cell containing half the number of chromosomes of a somatic cell and able to unite with one from the opposite sex to form a new individual; a gamete.
*Law of Independent assortment* - how do chromosomes align -eg - Explain why Prader-Willi and cystic fibrosis are not always inherited together*
The law of independent assortment - says that chromosomes, align independently of each other when being passed from parent to child. -eg-chromosome 7 and chromosome 15 do not directly influence each other's inheritance patterns during meiosis in parental gametes, and can be sent to sperm or eggs in any combination. Explains why Prader-Willi and cystic fibrosis are not always inherited together - one child might have cystic fibrosis as well as Prader-Willi. and another child might have cystic fibrosis, but not Prader-Willi.
tail of sperm
The microtubules from the mid-piece extend here and are activated by ATP that allow the flagella to proper in fluid environment.
p-value
The p-value is the probability of observing a result due to chance alone, assuming that the null hypothesis is true The p-value ranges from 0 to 1 and is generally interpreted as follows: p > 0.05 signifies that - There is a greater than 5% probability that the observed result is due to chance alone, not due to an actual association between the variables under study. - Therefore, they are not statistically significant. p ≤ 0.05 signifies that - There is a 5% or lower probability that the observed result is due to chance alone. - Therefore, they are statistically significant. The plasma triglyceride level in mutation carriers is significantly lower than the plasma triglyceride level in mutation noncarriers (p = 0.023)
The rough endoplasmic reticulum (RER)
The rough endoplasmic reticulum (RER) - has long, folded membranes coated with attached ribosomes that translate proteins destined for secretion into the rough ER lumen.
Neuroendrocrinology ― relation between neurons and hormonal systems
The secretion of hormones from the anterior pituitary is mediated by regulatory neurohormones released into the blood by hypothalamic neurons. In contrast, the secretion of stored hormones from the posterior pituitary is induced by depolarization of the nerve terminals. Posterior pituitary hormones are synthesized in hypothalamic neurons and then transported down the axon to the axon terminals in the posterior pituitary, where they are stored. The secretion of stored hormones from the posterior pituitary is mediated by action potentials that cause exocytosis of neurosecretory vesicles.
Western Blot + Autoradiography Western Blot = control used to detect the presence of protein of interest
The western blot was performed with an anti-Dg antibody that detects all Dg molecules and confirms that they are present, even if they are not radiolabeled. - The researchers can then be sure that the absence of bands in the autoradiogram is due to failure of the relevant enzyme to modify Dg and not due to a problem with isolating Dg itself. Note that unmodified Dg runs further on the gel because the absence of carbohydrates yields a smaller molecule. Educational objective: A proper experimental approach requires controls to confirm that the results are related to the conditions being tested rather than experimental error or confounding factors. Controls can be positive or negative, showing what a positive or a negative result should look like, respectively.
amphibians
They usually have soft, moist skin that is protected by a slippery layer of mucus. They also tend to live in moist places or near water to keep their bodies from drying out.
Periosteum
Thin layer of connective tissue that covers and protects the long bone
Thin-layer chromatography (TLC)
Thin-layer chromatography (TLC) - separates compounds based on *polarity* - stationary phase, - solvent mobile phase, and - detector (UV). - Polar compound will H-bond to the polar stationary phase on the TLC plate whereas the - The non-polar compound cannot H-bond. The more polar compound has a smaller Rf value than The non-polar compound. Therefore, TLC can be used to assess product purity by comparing - If a single spot with a larger Rf than that of the polar compound is visible on the product sample track on the TLC plate, then the isolated product is pure.
What kind of AA cause steric constraints?
Those with large side chains (F, I, L, K, M, R, W, and Y)
Prosthetic group
Tightly bound cofactors
Function of the following - General function of all - ovaries (2) - fallopian tube (2) - cervix Impaired function will result in?
To enable pregnancy & delivery Ovaries - produce gametes (oocytes) - secrete female hormones (Estrogen & Progesterone) Fallopian tube - this is where fertilization takes place - oocyte is transferred from ab cavity to uterus Cervix - The barrier separating uterus and vagina sperm can't pass through → infertility
What is the total water loss of an eel? "...eel was transported into seawater that had been treated with the volume marker phenol red. After 20 hours, the eel's gut contained 2.3 mL of fluid but showed a phenol red concentration equivalent to 12.3 mL of ingested seawater..."
Total water loss =renal H2O loss + extrarenal water loss 10 mL = 2.3 mL + extrarenal water loss Extrarenal water loss = 10 mL − 2.3 mL = 7.7 mL -eel lost 7.7 mL H2O extrarenally.
Which cells are the least specialize?
Totipotent stem cells, give rise to both placental and fetal cells
G-protein receptors
Typically, when a G-protein-coupled receptor binds to its particular ligand, the receptor either stimulates or inhibits the production of cAMP by the adenylyl cyclase associated with that receptor.
What are the STOP codons?
UAA= U are away UAG= U are gone UGA= U going away
Difference btw oligodendrocytes in the CNS, and Schwann cell in the PNS
Unlike oligodendrocytes in the CNS, each Schwann cell forms a myelin sheath for a single neuron in the PNS
Vacuum distillation
Vacuum distillation - is appropriate for compounds that have boiling points >150°C, which may decompose when heated beyond this temperature. Vacuum is added; - To *avoid decomposition when heated beyond 150°C* - Vacuum *decreases the pressure* of the system and consequently lowers the b.pts of the mixture components. ↓Pressure = ↓B.pt
Antibodies that recognize different antigens have different ___ regions
Variable
Variable expressivity
Variable expressivity - refers to the ability of a single genotype to give rise to multiple phenotypes. In the context of disease, two patients with the same mutated allele may exhibit markedly different clinical symptoms. T - individuals with the mutation exhibit variable phenotypes such as mild to severe degrees of hearing loss
How does adrenal medulla & cortex respond to stress
Vasoconstriction (narrowing) of blood vessels supplying the intestines, kidney, and other abdominal organs decreases blood flow to these organs and conserves oxygen/nutrients for other tissues. Vasodilation (widening) of blood vessels leading to the heart and skeletal muscles increases oxygen/nutrient delivery to these organs. In general, the hormones secreted from both the adrenal medulla and cortex function to alter blood pressure and allow the body to respond to stressors.
ROYGBIV - Wavelengths
Violet = 400-450 Blue = 450-490 Green = 490-565 Yellow = 565-590 Orange = 590-650 Red = 650-740
kcat
Vmax/[E]t
Parallel evolution
When 2 *more closely* related species (more common ancestor) *continue* to evolve same traits to adapt to *similar* environments
enveloped viruses
Which viruses can fuse their membranes with the cell membrane?
X-linked Dominant condition X-linked Recessive condition Autosomal Recessive condition Mitochondrial
X-linked Dominant condition - If only X*Y affected →All daughters affected - If only X*X* affected →50% daughters & 50% son affected - Need 1 copy of dominant allele to inherit X-linked Recessive condition - If only X*Y affected →All daughters carriers - If only XX* carrier →50% daughters is carrier & 50% son affected - Need 2 copies of allele to pass to daughter - Need 1 copy of allele to pass to son Autosomal recessive condition (Aa x Aa) - Need 2 copies of (aa) to inherit disease Mitochondrial - If only X*Y affected → 0% of offsprings - If only X*X* affected → 100% of daughters
tRNA
a type of RNA molecule that helps decode a messenger RNA (mRNA) sequence into a protein transcribed in the nucleolus by RNA polymerase III found in the cytoplasm
Cloning vector
circular DNA molecule found in bacteria and viruses
Subcutaneous layer of Skin
composed of adipose cells that insulate body
Heteromultimers:
composed of different subunits
E
glutamate
Vmax =
kcat x [E]total
Transcription factors rely on what to gain nuclear entry?
nuclear localization sequence
NMR Shift
ppm; determined by the amount of deshielding by adjacent atoms
endogenous
"growing or originating from within an organism / having an internal cause or origin.
osteoblasts and osteoclasts
"osteoblasts: a cell that secretes the matrix for bone formation. osteoclasts: A cell that nibbles at and breaks down bone and is responsible for bone resorption.
Somatostatin Stomach Function
"somatostatin inhibits the secretion of pancreatic hormones, including glucagon and insulin. This produces a net decrease in gastric/duodenal digestive activity. Low gastric pH stimulates the release of somatostatin from Antral D-cells.
liver function
- absorption of fats in small intestine - production of bile - detoxification of poisons
*How do blood vessels control blood flow/BP? - vasoconstriction of what vessels, to where, why? - vasodilation of what vessels, to where, why?*
- change blood vessel diameter to alter BP Vasoconstriction - of blood vessels supplying tissues -↓blood flow→conserve O₂/nutrients to tissues Vasodilation - of blood vessels supplying heart & muscles - ↑blood flow → ↑O₂/nutrients to organs
Function of Blood (3) Major function of Respiration - what type of tissue is blood?
- delivery of O₂ and nutrients to tissues - circulation of hormones + ions + fluids - removal of CO₂ & waste products - Remove CO₂ from blood via gas exchange at the alveolar capillary beds
Resting phase:
-RMP restoration -Both voltage-gated Na+ and K+ channels are inactive - The Na+/K+ pump restores the RMP.
Turnover number Kcat of an enzyme-substate system:
-Represents the number of reactions catalyzed per second per enzyme under saturating conditions. -Calculate:Vmax/[E] -Used to compare enzymes at high substate concentrations
Thiol
-SH
Cell migration in embryogenesis:
-The movement of cells into their final positions within the embryo. 1. Neural crest -Gives rise to many PNS structures 2. Neural tube -Gives rise to CNS
Common Neurotransmitter for Action potentials & function (3) primary neurotransmitter of the parasympathetic division primary neurotransmitter of the sympathetic division are? - Only one found on preganglionic neurons - Only one found on postganglionic cell membranes & membranes of skeletal muscle cells - Only one found on effector cell membrane
1) Acetylcholine (ACh) - ANS/parasympathetic - used in somatic NS - by triggering *muscle* contraction at the neuromuscular junction 2) Epinephrine stimulates fight/flight response 3) Norepinephrine -ANS/sympathetic ↑ arousal, ↑ alertness and focuses attention. cholinergic - acetylcholine (ACh) - on pre & postganglionic neurons (para) adrenergic - epinephrine and norepinephrine - on postganglionic neurons (sym) Others type of cholinergic receptor Nicotinic receptors - on postganglionic cell membranes (para & sym) & membranes of skeletal muscle cells Muscarinic receptors - on effector cell membranes (para & sym)
1) Microglia https://www.khanacademy.org/test-prep/mcat/organ-systems/neural-cells/v/microglia
1) Microglia = phagocytose waste - are the primary immune cells of the (CNS) - they act as macrophages by phagocytizing pathogens, damaged cells, and other waste materials. - arise from mesoderm
blood vessel dilation results in
1) increased oxygenation of cells 2) increased blood flow (lower resistance) 3) if arteries/arterioles --> decreased BP and HR
list 3 ways exogenous genetic material can be introduced into a bacterial cell
1) transformation 2) transduction 3) conjugation
Survival curves
Educational objective: Survival curves plot percent survival against an independent variable, usually time or dosage. Survival curves can be used to determine LD50, defined as the minimum dose causing death in 50% of test subjects.
Main driving force of Tertiary structure?
Hydrophobic effect
Nonoxidative fibers generate ATP via ?
anerobic glycolysis
do prokaryotes have mitochondria?
no
G2 hase
pre-mitosis growth, DNA damage repair
Neural tube
precursor of CNS, pinches off the *ecto*derm
function of glucagon
prevent blood glucose levels dropping too low. To do this, it acts on the liver in several ways: It stimulates the conversion of stored glycogen (stored in the liver) to glucose, which can be released into the bloodstream.
total activity equation
total protein x specific activity
autosomal
traits equally present on both sexes
anabolic processes form thermodynamically ____ and kinetically _____ bonds
unstable (requires energy input) stable
non-enveloped or naked viruses
viruses that are able to survive harsh conditions
the perineum
The perineum is below the pelvic diaphragm and between the legs. It is a diamond-shaped area that includes the anus and, in females, the vagina.
https://www.khanacademy.org/test-prep/mcat/organ-systems/neuron-membrane-potentials/v/neuron-resting-potential-mechanism
The presence of protein channels in the cell membrane allows passive transport of certain ions down their electrochemical gradient. - This selective membrane permeability is responsible for generating the resting membrane potential in nerve and muscle cells. - Active transport pumps help maintain the concentration gradient and are critical for maintaining the resting membrane potential.
hydrostatic pressure
The pressure exerted by a fluid at equilibrium at a given point within the fluid, due to the force of gravity. Hydrostatic pressure increases in proportion to depth measured from the surface because of the increasing weight of fluid exerting downward force from above.
PROKARYOTES & EUKARYOTES CELLS
PROKARYOTES & EUKARYOTES CELLS
Western blot detects what?
PROTEINS
Increased activity of osteoclasts is linked to increase in which hormone?
PTH
Cathode
*negatively charged electrode*; attracts cations (high-pH end)
Gastrulation:
-Process by which the germ layers (endoderm, mesoderm, ectoderm) form in the developing embryo.
wobble hypothesis
Ability of the tRNAs to recognize more than one codon; the codons differ in their third nucleotide.
Lymphoid progenitor cells go on to become:
B cells, T cells, and NK cells
What binds to troponin?
Ca2+ (calcium)
Is yeast eukaryotic or prokaryotic?
Eukaryotic
mutagen
a physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations above the natural background level. most mutagens are carcinogens
dissociation constant
a small Kd represents a strong binding affinity of the antibody
arterioles
a small branch of an artery leading into capillaries.
descending loop of henle
has low permeability to ions and urea, while being highly permeable to water.
salt bridges
ionic attractions between the charges of the acidic and basic residues of amino acid residues (*oppositely charged*)
if pka HIGHER than pH
ionizable group is PROTONATED, net charge *MORe positive*
translocation
is a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes.
Kinesin
move cargo in anterograde axonal transport. Nucleus to distal site
specific activity
activity of target protein/total protein obtained indicates purity o f protein
9-10 ppm
aldehyde
Homomultimers:
all subunits are identical
3300-3400
amines
carboxylic ester and fat structure
are similar
mRNA turnover is critical for
cell differentiation turnover: mRNA destruction to prevent continuous protein production
Alternative splicing
produces multiple protein products from the SAME gene, not multiple similar genes
Green fluorescent protein (GFP)
protein often used to track the mobility of proteins in a cell
substitution
substitution - is either a silent or a missense mutation, silent - the nucleotide change corresponds to the same amino acid as in the original sequence missense - the nucleotide change corresponds to a different amino acid
This formula is everything - explain what happens when CO₂ in blood ↑ & response
CO₂ + H₂O ↔ H₂CO₃ ↔ HCO₃ + H⁺ When CO₂ in blood ↑ → shifts eqB to right → H⁺↑; pH↓ → leads to respiratory acidosis Response to ↑CO₂ in blood = Hyperventilation - will cause removal of CO₂ from blood When CO₂ in blood ↓ → shifts eqB to left → H⁺↓; pH↑ → back to normal
Urethra
Canal through which urine exits body from bladder
Cardiac output (equation)
cardiac output = stroke volume x hear rate
mesoderm gives rise to
cardiovascular system, musculoskeletal system, lymphatic system, etc
PTH, Vit D, Calcitrol & Calcitonin
PTH release stimulates - the conversion of Vit D (inactive form) to calcitriol (active form of vit D) in the kidney. Calcitriol = promote absorption of dietary Ca²⁺ and PO₄³⁻ from the small intestine. Stimulating calcitriol synthesis, - induces absorption of dietary Ca²⁺ from the small intestine - Promoting bone resorption (osteoclast activity), → releasing Ca²⁺ into the blood - ↑Ca²⁺ reabsorption and PO₄³⁻ excretion in the kidneys In response to ↑Ca²⁺, calcitonin is secreted by the thyroid glands. - Calcitonin mainly acts to ↓plasma Ca²⁺ by ↓osteoclast activity (bone resorption) and ↑renal excretion of calcium. Although calcitonin is a less consequential regulator of calcium homeostasis than PTH in humans, its net effect opposes that of PTH and calcitriol.
Pancreas Hormones - 3 ways pancreas hormones are transferred - what is the functional unit of endocrine pancreas - what is it made up of? - what 3 hormones does it secrete? - how do they respond to ↑/↓glucose, inhibition, paracrine, endocrine function
Pancreas - transfer hormones the ffg ways - Paracrine (neighboring cells) - endocrine (via bloodstream to tissues) - exocrine (via duct to epithelial surface) --> ducts like sweat, saliva, enzymes The functional unit of endocrine pancreas - Islets of Langerhans --> made up of - α,β,δ (somatostatin)cells 1) α cells = glucagon = ↑glucose in blood - when blood glucose ↓ = release glucose to blood - inhibit β cells and inhibit paracrine function 2) β cells = insulin = ↓glucose in blood - when blood glucose ↑ = ↑glucose uptake from blood - inhibit α cells and exhibit paracrine function 3) δ cells = somatostatin = regulate α and β - regulate α and β cell production - produce somatostatin to inhibit digestive function & ↓insulin & glucagon release
ROYGBIV - Perceived and Absorbed Colors
The color of a substance is determined by - the wavelength of light it absorbs, which is, in turn, determined by - the electronic structure of the molecule of interest. In general, a substance appears to be the color that is complementary to the color that is maximally absorbed. R (perceived) is complimentary to G (absorbed) O (perceived) is complimentary to B (absorbed) Y (perceived) is complimentary to V (absorbed)
4-nitrophenol
The compound 4-nitrophenol contains the following functional groups: - Hydroxyl group (-OH) - Aromatic ring - Nitro group (-NO2)
3-5 ppm
alkane w/ heteroatom
5-7
alkene
inflammation at the cellular level
chemicals from the body's white blood cells are released into the blood or affected tissues to protect your body from foreign substances. This release of chemicals increases the blood flow to the area of injury or infection, and may result in redness and warmth.
Heterochromatin:
consists of DNA tightly coiled around histones and is not readily transcribed by RNA polymerase.
constitutively active gene model
constitutively active gene model - the gene of interest is transcribed at a relatively constant rate regardless of current cell conditions. - This results in increased gene mRNA and protein activity.
Northern Blot
detect RNA
Southern Blotting
detects DNA; separate DNA w/ gel electrophoresis then attach radiolabeled DNA probe
Northern Blotting
detects RNA; separate RNA w/ gel electrophoresis then attach radiolabeled RNA probe
Western Blotting
detects specific protein; separate w/ SDS Page then attach radiolabeled antibody; protein of interest will be visible
NMR Splitting
determined by # of neighboring hydrogens; ex. singlet means no neighbors; triplet means 2 adjacent hydrogens
Sandwich ELISA
first add primary antibody; then protein of interest; then secondary antibody
how do histones associate with DNA
forms salt bridges between the + AA and - phosphate groups of DNA
Totipotent stem cells
found *only in zygote* up to 8-cell stage, greatest potency, can differentiate into ANY cell type
Almost all carbohydrates are found in what configuration?
fructose, glucose, galactose, ribose (*all free monosaccharides* also are reducing; can form glycosidic bonds)D configuration
Greater negative charge= ___ nucleophilicity
greater
reverse transcription
involves making cDNA from an mRNA template
polyploidy
having more than 2 copies of each chromosome
Alternative splicing
1 gene transcript processed to various mRNA proteins, *increases protein diversity*, but NOT genetic
sphingomyelin
A sphingophospholipid containing a sphingosine backbone and a phosphate head group.
autosome
not a sex chromosome
*Name the germ layer - notochord, melanocyte, myocytes, osteocyte, mucous cells(stomach), sperm & egg, Islet beta cells, Epidermis, Neurons, RBCs, alveolar cells*
notochord = reproductory = Mesoderm melanocyte = skin pigment = Ectoderm myocytes = muscles = Mesoderm osteocyte = bones = Mesoderm mucous cells(stomach) =dig lining = Endoderm sperm & egg = germ cells Islet beta cells = Pancreas = Endoderm Epidermis = Skin = Ectoderm Neurons = nervous = Ectoderm RBCs = circulatory = Mesoderm alveolar cells = resp lining = endoderm
Length of preganglionic & postganglionic axons (sympathetic vs parasympathetic) and why? - Preganglionic neuron - Postganglionic neuron
parasympathetic - long preganglionic and short postganglionic - ganglia are in the walls of visceral organs sympathetic - short preganglionic and long postganglionic - ganglia are close to the spinal cord Preganglionic neuron = in CNS -cell body (in brain/spinal cord) →axon (part of cranial or spinal nerve) →autonomic ganglion, → synapses with a postganglionic neuron Postganglionic neuron = in PNS -cell body & dendrites (in autonomic ganglion) →synapse with one/more preganglionic axon → terminates in a visceral effector.
fusiform gyrus
part of the visual system in the brain, and plays a role in high level visual processing and recognition. Damage to this part of the brain could result in prosopagnosia.
Termination (Euk. translation)
polypeptide released when stom codon detected in *A site*-> end of translation
PTH
secreted in response to LOW blood calcium and stimulates bone resorption by *osteoclasts* -> increase in blood Ca2+
Primary structure
sequence of AA from N-terminus to C-terminus, formed by peptide bonds
Adenine binds to what nucleic acid in RNA?
uracil
Gram Staining
use crystal violet following by safranin stain; gram positive will absorb crystal violet and appear purple; gram negative will absorb safranin and appear pink
what will happen if the appendix ruptures?
you will need antibiotics to treat E.coli that will enter the abdominal cavity from the appendix/colon - the appendix is continuous with the colon
Explain main reason Asthmatic Patients have issues with gas exchange
- have constricted airways which restricts inhalation - causes ↓ in fresh air → ↓ gas exchange in lungs → ↓CO₂ removed→↑CO build up in blood
Telomeres:
-highly repetitive stretches of DNA at the ends of a chromosome. -They are shortened by each round of DNA replication, and protect the rest of the chromosome from degradation. -telomeres do not encode any gene products; if they did, the information for those products would be lost upon replication and could harm the cell.
Variable region of antibody
binds the antigen
hydrolase enzymes catalyze what type of reactions? (___ase enzymes)
catalyze reactions between a specific substrate AND water to break a covalent bond
Enantiomers
enantiomers = chiral = non-superimposable mirror images. Enantiomers have many of the same chemical and physical properties, including melting and boiling points, solubility, and polarity, although - *Enantiomers differ in the way that they interact with plane-polarized (linear) light.* A 50:50 mixture of enantiomers is known as a racemic mixture.
Luciferase
enzyme responsible for bioluminescence (light emission)
function of sphingolipids
essential structural components of plasma membrane
Gene flow,
Gene flow, - due to migration, - increases genetic diversity by introducing new alleles to the gene pool. Therefore, small populations with low genetic diversity are more likely to benefit from gene flow and therefore are less likely to go extinct.
negative control
Group with no response expected
What are the benefits of MCH to Natural selection, gene flow, random mating
MHC - encodes surface receptors on cell to help activate adaptive immune system ↑MHC = ↑ability to combat infection = ↑fitness
Major Histocompatibility Complex (MHC)
MHC alleles - encode surface receptors on all nucleated cells that play a role in the activation of the adaptive immune system. Typically, increased MHC variation - enhances an organism's ability to combat a variety of infections and diseases. - As a result, it is associated with increased fitness
Macula densa cells
Macula densa cells - are part of the DCT of Nephron - gets a taste of the water and sense ↓Na+ and realize it's due to ↓filtration by the glomerulus (ie ↓BP) - They send prostaglandins to the JG cells - this triggers the release of Renin
Spingolipids
Structural lipids, help fluidity and curvature of membranes; *cannot* be readily hydrolyzed or used for energy storage
Waxes
hydrolyzable lipids; FA chain bound to long-chain alcohols by ester bond
what 3 organs are involved with the menstrual cycle?
hypothalamus-pituitary-ovary. The hypothalamus controls the pituitary, FSH and LH produced by the pituitary and the ovary produces estrogen and progesterone
Desmosomes
provides tensile strength to epithelial sheets by anchoring cytoskeleton. They are both inside and outside of the cell and prevent the ripping apart of the skin when the pressure is applied.
what type(s) of muscle contain striated fibers?
skeletal muscle and cardiac muscle
Nucleation of 3 muscle types
skeletal= MULTInucleated cardiac= 1-2 nuclei smooth= UNInucleated
hemolysis
the rupturing (lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma)
Functions of the Sympathetic nervous System (SNS) eg Functions of the Parasympathetic nervous System (PNS) eg
(SNS) - prepares body for a perceived stressful situation - *General response* - eg- a. extreme heat, extreme cold, running a marathon on a sunny day, blushing, piloerection, GI immotility (PNS) - maintains the bodily systems after stress - *Specific response* -eg- sleeping, penile erection
How to calculate total number of nucleotides in an mRNA molecule
(number of AAs in the protein) X (number of nucleotides in a codon,3)
Dehydration & Hydrolysis
*REMEMBER:* Dehydration = (- H₂O) - Product remain intact Hydrolysis = (+ H₂O) - Product is broken up Peptide bond *formation* is a *dehydration reaction* rather than a hydrolysis reaction because water is released upon bond formation. Peptide bond *cleavage* is a *hydrolysis reaction* because it requires the addition of H2O across a peptide bond
Incomplete dominance
*intermediate phenotype observed* -> resulting offspring have a phenotype that is a *blending of the parental traits* (i.e. red/white -> pink)
Heterochromatin
*tightly* condensed complex of DNA wrapped around histones, is transcriptionally *inactive*
SUMMARY - what is glomerular filtration rate (GFR). - ↑/↓HP in the glomerulus = - how does blood enter and exit glomerulus? - effect of vasoconstriction of the afferent arteriole - Urine production is influenced by the GFR, HOW?
- Blood is filtered in the glomerulus by high hydrostatic (blood) pressure, which forces excess fluid and waste products (filtrate) into Bowman's space. Proteins and cells are too large to pass through the pores. glomerular filtration rate (GFR) = Volume of fluid filtered via the kidney per unit time - ↑HP in the glomerulus = ↑GFR - ↓HP in the glomerulus = ↓GFR Blood enters glomerulus via afferent arteriole Blood exits glomerulus via efferent arteriole - The degree of vascular constriction of these two arterioles controls the rate of blood flow into and out of the glomerulus, - thereby affecting the GFR through changes in glomerular hydrostatic pressure. vasoconstriction of the afferent arteriole - limit blood flow to glomerulus, = ↓glomerular HP and ↑in resistance = ↓GFR. Urine production is influenced by the GFR, 1) the rate of reabsorption (movt of substances from the filtrate back into the bloodstream), 2) the rate of secretion (movt of substances from the bloodstream to the filtrate). ↓HP =↑in resistance =↓GFR =↓filtrate produced = ↓urine output
In a group of insect where 60% have red eyes, 30% have apricot eyes, 5% have white eyes, and 5% have pink eyes. Which of these eye colors would be designated the wild type? - *what is wild type - what are the others called?*
- Red Wild type = the most prevalent, (naturally occurring in the "wild") phenotype for a certain trait. - white, pink, and apricot are due to genetic variations of the gene that codes for eye color.
Steps in Translation (IET) - from binding of subunit to *dissociation*
- Requires Energy 1) Small (40S) subunit binds 5'cap of mRNA Large (60S) subunit binds tRNA 2) Ribosome continues to elongate chain by reading each mRNA in 5' to 3' direction 3) stop codon is read & release factors induces dissociation of ribosome-mRNA complex
Parts of the brain - scientific & lame man What muscles are involved in voluntary & Involuntary movts
- prosencephalon (forebrain) - mesencephalon (midbrain) - rhombencephalon (hindbrain) voluntary movement - skeletal muscles involuntary movement - cardiac muscle, smooth muscle, lacrimal gland
Inductive signaling
-An inducer (the signaling cell) releases chemical signals that act on competent neighboring cells by regulating the expression of specific genes required for cell determination
Female reproductive tract:
-Consists of: ovaries fallopian tubes uterus cervix vagina -Each of these tissues performs specialized functions that enable preganancy and delivery
Multimeric proteins:
-Contain multiple polypeptide subunits. -May be bound together by disulfide bonds, which must form in oxidizing environments and can only be broken by reducing agents.
Transmembrane domains of proteins:
-Cross the hydrophobic environment of the phospholipid bilayer.
MicroRNAs (miRNAs)
-Example of noncoding RNA -Silence gene expression at the transcriptional level. -Bind complementary sequences on target messenger RNA (mRNA) molecules -Inhibit expression of target mRNA by blocking translation or marking for its degradation.
Pluripotent stem cells:
-Give rise to only fetal cells (ex. all cell lineages from the 3 germ layers)
Cell fate:
-Influenced by inductive signaling between cells in the early embryo.
Dissociation Constant Kd:
-Measures the affinity of a protein for its ligand -Small Kd= low tendency of the protein-ligand complex to degrade and a high affinity of the protein for its ligand.
Mesoderm
-Middle layer -Gives rise to the circulatory system, musculoskeletal system, and part of the urinary and reproductive systems
Vasoconstriction:
-Narrowing blood vessels -Reduces blood vessel volume--> increased BP -Reduces blood flow and can redirect blood flow to other tissues
Base pair mismatches:
-Occur when DNA polymerase incorporates an incorrect nucleotide into the newly synthesized strand.
Ectoderm
-Outermost layer -Gives rise to the nervous system (neurulation) and developed into the integumentary system (hair, skin,nails,lining of mouth, nostrils, and anus)
DNA mistmatch repair:
-Process by which base pair mismatches between the daughter and parent strands are corrected during DNA replication.
Stereospecific reactions:
-Produce chiral molecules, which have chiral centers in a specific conformation.
Morphogens:
-Signaling molecules that influence cell differentiation in the embryo. -They are released by signaling cells and diffuse outward to alter gene expression in competent cells in concentration-dependent manner.
Ovaries:
-The female reproductive organs that contain oocytes and secrete female sex hormones (estrogen, progesterone) -These hormones influence female reproductive function, and are directly responsible for the development and maintenance of female sex characteristics
Electrical Synapse:
-Transfer information from one cell to another via passive ionic current flow through gap junctions.
Chemical Synapse:
-Use neurotransmitters to transfer information, which is a slower process
Southern Blot:
-Used to detect a particular sequence of DNA -Can be used to determine relative gene count
Northern Blot:
-Used to detect a particular sequence of RNA -CANNOT be used to determine relative gene count -Used to assess gene expression in different tissues
Saltwater fish osmoregulation
-fish has to constantly drink water because they keep losing more water to their surroundings; their urine is concentrated with ions *Lose H2O, Gain Na+
Totipotent Stem cells:
-least specialized cells -give rise to both placental and fetal cells
Transcription factors:
-upregulate or downregulate transcription by influencing the ability of RNA polymerase to bind a promoter. -Transcription factors that increase transcription are called activators and facilitate RNA polymerase binding whereas those that decrease transcription are called repressors and inhibit binding.
If cldnk mRNA is found in the same cells as the mRNA, then cldnk must be expressed in oligodendrocytes. *if probe that is complementary to cldnk mRNA hybridizes to cells that also express plp1A, then cldnk is expressed in oligodendrocytes.
...
Mismatch Repair System process
1. Mismatch detected 2. Endonuclease cleaves 3. DNA pol adds correct 4. DNA ligase seals
describe process of apoptosis
1. mitochondrial membrane permeabilized 2. cytochrome C leaves mitochondria 3. increase in cytosolic cytochrome c 4. cytochrome C activates caspase in cytoplasm 5. caspase activates proteases and other degradative pathways
Each pH unit above/below pKa alters ratio of (de)protonated species by factor of ___ ?
10
How long is the menstrual cycle How many phases are there? What happens at each phase - where does it take place - # of days - effect on LH, FSH, Estrogen, Progesterone
26-28 days Follicular/Menses + Proliferation Phase - takes place in the follicle - (day 1-13) - ↑LH, ↑FSH, ↑Estrogen, ↓Progesterone Ovulation (day 14) Luteal Phase/Secretory Phase - takes place in the corpus luteum - (day 15-28) - ↓LH, ↓FSH, Estrogen (starts ↓ & ↑later), ↑Progesterone
What is the size of the pSKII plasmid after it is digested by EcoRI and XhoI and the cldnk gene is inserted? *Given: pSKII= 2958 bp; ECORI -> Xhol= 32 bp; cldnk= 915bp
2958 (pSKII) plasmid− 32 (Xhol) digested + 915 (cldnK) inserted = 3841 bp
5) Schwann cells https://www.khanacademy.org/test-prep/mcat/organ-systems/neural-cells/v/schwann-cells
5) Schwann cells - wrap the axons of some neurons with myelin to increase conduction speed. - each Schwann cell forms a myelin sheath for a single neuron in the PNS - arise from ectoderm
cortical nephrons
85% of all nephrons short nephron loops efferent arterioles branch into peritubular capillaries around PCT and DCT
native PAGE gel
A native PAGE gel contains - no denaturants or - reducing agents and - allows DNA molecules to maintain their double-helical structure and traverse the gel in their native (unaltered) state. Individuals with the mtDNA mutation would be expected to show - one band, representing the undigested product - - and two bands, representing digested products Samples without the mutation would show only the - undigested band
In which phase of meiosis, are the sister chromatids separated to opposite poles of cell?
ANAPHSE II
Oncogene
According to the passage, c-Myc overexpression leads to early cancer development (ie, B-cell lymphoma) in Eμ-Myc mice. - Therefore, c-Myc is most likely an *oncogene* Oncogene - is a mutated or overexpressed gene that induces uncontrolled cell growth by promoting cell cycle progression or inhibition of apoptosis. As a result, c-Myc levels would be higher in Eμ-Myc (Eμ) mice than in wild-type mice to promote cancerous cell growth.
Why is genetic code considered degenerate or redundant?
Although there are 64 codons, ONLY 20 AA used for protein synthesis
https://www.khanacademy.org/test-prep/mcat/organ-systems/neuron-membrane-potentials/v/neuron-action-potential-description
An action potential (AP) is a rapid electrical impulse that travels from the neuron's cell body to its axon terminal. The AP consists of a series of membrane potential changes as follows:
Genes with high sequence identity:
Are evolutionary related, having a common origin. They generally arise by gene duplication, and over time, may mutate and fulfill distinct roles within an organism
Autoradiography
Autoradiography - only detects molecules that contain radioactive atoms; - lanes containing molecules with no radiolabel will appear empty. However, it is also possible that those lanes appear empty because they contain no molecule at all, with or without radiolabels.
Cation Exchange columns
Beads are *negatively* charged and *bind cations*
size exclusion chromatography
Beads contain tiny pores; *LARGE molecules ELUTE FIRST*
Glycosidic bond
Bond bw anomeric carbon of carbohydrate and ANY othe rbiomolecule
Where does production of leukocytes (WBCs) take place?
Bone marrow
Fluid Mosaic Model - *what migrates? - in what direction?*
Cell membrane is said to be fluid because - it's various non-phospholipid stuff are able to migrate *laterally* through the entire phospholipid rich surface of the cell in all direction
multipotent cells
Cells that can differentiate into many specialized functions but limited in that "committed" to *specific lineage*
Inbreeding depression
Characterized by loss of genetic diversity, reduced fecundity, and decreased fitness
Diff btw Co-dominance & Incomplete dominance - is it observed in Phenotype of homozygous or heterozygous individuals?
Co-dominance = Co-expression -eg- Red + White = Red & White flower Incomplete dominance = Blended/Intermediate -eg- Red + White = Pink flower - Both are observed in Phenotype of *heterozygous* individuals
Diff btw Crossing Over & Alternate Splicing - what kind of diversity do they affect?
Crossing Over = ↑ genetic diversity Alternate Splicing = ↑ protein diversity
recombinants
Crossing over can produce new combinations of alleles within a chromosome by moving some alleles of the maternal copy to the paternal copy and vice versa. New combinations of alleles are called - recombinant, whereas combinations that already existed in the parent are called - parental.
Transcription factors translated where?
Cytoplasm
DNA polymerase
DNA polymerase - synthesizes daughter strands in a 5′ → 3′ direction only. One daughter strand is synthesized continuously toward the replication fork (leading strand); the other strand is synthesized discontinuously in a direction away from the replication fork (lagging strand), with more and more segments added as the replication fork progresses. This process results in the formation of Okazaki fragments, short stretches of newly synthesized DNA separated by RNA primers.
-DNA sequencing and Southern blotting are ____ assays are used to assess relative quantity of genes between tissue types. -Northern blotting is an _____ assay used to assess gene expression in different tissues.
DNA, RNA
Stratum Basale
Deepest layer of epidermis; consists of single row of *stem cells* that continually divide-> new stem cells
Fallopian tubes
Duct structures lined with motile *cilia* that transfer ovulated oocyte -> uterus; *main site of fertilization*
Green fluorescent protein (GFP)
Educational objective: Green fluorescent protein (GFP) - is frequently used to track the mobility of proteins in a cell. The protein of interest is tagged with GFP, and its movement, localization, and expression can be studied in cells based on the fluorescence emitted.
Hardy-Weinberg equations
Educational objective: Hardy-Weinberg equations can be used to relate allele frequencies and genotype frequencies. Genotype frequencies are equal to the probability of inheriting each genotype, with the frequency of homozygotes equal to p2 or q2 and the frequency of heterozygotes equal to 2pq. p + q = 1: If two versions (alleles) exist for a given gene, respective allele frequencies are commonly denoted as p, which represents the major (most common) allele, and q, which represents the minor (less common) allele. Statistically, the sum of these frequencies must equal 1. p2 + 2pq + q2 = 1: Genotype frequency can be determined by the probability of inheriting a genotype and is therefore dependent on allele frequencies. The frequency of homozygotes is equal to p2 or q2 whereas the frequency of heterozygotes is equal to 2pq.
Is phosphodiester bond formation exer or endergonic?
Endergonic
Method of Cell proliferation in Euks and Prok somatic & germ cells
Euk Somatic Cell - proliferate by completion of M phase Prok Somatic Cell - proliferate via binary fission Euk Germ Cell - proliferate by completion of meiosis
Extraction
Extraction - separates compounds based on *solubility* in a particular solvent; *This method uses two immiscible solvents that make up the aqueous and organic layers* No stationary phase, mobile phase, or detector is used in extraction.
Describe process of fermentation & glyconeogenesis - pyruvate oxidizes ____→_____ - in Glyconeogenesis ____ is converted to ____ - For Proks; pyruvate → enzyme → - For Euks; pyruvate → enzyme → - Is O₂ required for either? - are the active during anaerobic conditions?
Fermentation = No O₂ required - metabolizes pyruvate under anaerobic conditions to oxidize NADH → NAD⁺ For Proks; Pyruvate + NADH←(pyruvate decarboxylase) → Acetaldehyde + CO₂ ←(Alcohol dehydrogenase) → Ethanol + NAD⁺ For Euks; Pyruvate + NADH ← (lactate dehydrogenase)→ Lactic acid + NAD⁺ Glyconeogenesis = No O₂ required - Process by which non-carbohydrate carbon sources are converted into glucose Both do not require O₂; ∴ are active during anaerobic conditions in both Prok & Euks
Common NMR splitting patterns
For Single bonds - n + 1 rule - # of splits = n + 1 - n = # of neighboring Hs CC₄ = no coupled H + 1 neighbor H = singlet CC₃H₁ = 1 coupled H + 1 neighbor H =doublet CC₂H₂ = 2 coupled H + 1 neighbor H = triplet CC₁H₃ = 3 coupled H + 1 neighbor H = quartet Depends on # of neighboring Hs
Which additional extraction steps would cause phosphatidylethanolamine and 2,6-dimethoxyphenol to enter the aqueous layer consecutively
For phosphatidylethanol*amine* and 2,6-dimethoxy*phenol* to enter the aqueous layer consecutively, their ionic salts must be formed in sequence. Amine group in Phosphatidylethanolamine can be protonated to form a → ammonium salt; - Only strong acid eg H₂SO₄ or HCl should be added to protonate the amino group. Phenol group in 2,6-dimethoxyphenol can be deprotonated to form an → ionic salt. - Only strong bases eg NaOH or KOH are able to remove protons from phenols. The sequence of extractions steps is; - add a strong acid followed by a strong base.
Difference btw GC, HPLC, and TLC
GC = separates based on b.pt - mobile phase = gas - stationary phase = liquid solvent - detector HPLC = separates based on polarity - *mobile phase = liquid (under pressure)* - stationary phase = polar/non-polar column - detector - computer for data acquisition. TLC = separates based on polarity -*mobile phase = liquid(NOT under pressure)* - stationary phase = Polar - detector (UV) for Chromophores SC = separates based on size
Summary
GH - promotes tissue growth and utilization of fats. LH and FSH - regulates reproductive functions - In females - stimulate follicle maturation, ovulation, and estrogen production. - In males - regulates spermatogenesis and testosterone production Adrenal glands - secrete hormones that modulate the physiological stress response - "fight or flight" Insulin and Glucagon - regulates blood glucose concentration Insulin is secreted in response to high blood glucose levels to promote glycogen formation in the liver and uptake of glucose by cells. In contrast, glucagon is secreted in response to low glucose levels to promote gluconeogenesis and glycogen breakdown.
Gastric juice and Importance of acidic environment in stomach
Gastric juice is a digestive fluid primarily composed of - (HCl), which is secreted by parietal cells in the stomach. - acidic - pH of 1-3; Importance of acidic environment in stomach - for protein digestion (via activation of proteolytic enzymes) and - for killing harmful bacteria.
Gastric juice and Importance of acidic environment in stomach
Gastric juice is composed of - (HCl) - secreted by parietal cells in stomach Importance of acidic environment in stomach - for protein digestion (via activation of proteolytic enzymes) and - for killing harmful bacteria.
Differences & Similarities btw Genetic Drift & Bottle neck - caused by? - effect on genetic diversity, allele pop size, survival
Genetic Drift = Chance event, - eg- sampling error Bottle neck = Not by chance, -eg- natural disasters, human destruction BOTH - ↓ genetic diversity - ↑probability of a beneficial allele being removed and deleterious allele becoming fixed - can cause extinction in small population
What type of bacteria has a thick peptidocglycan layer?
Gram + (purple/dark stain)
Histone acetylation & deacetylation - effect of each process
Histone acetylation = (+) acetyl to histone tail - loosen Heterochromatin → Euchromatin - makes DNA region accessible - up-regulates transcription/gene expression H/deacetylation = (-) acetyl from histone tail - reverts Euchromatin → Heterochromatin - restrict DNA region accessibility - downregulates transcription/gene expression
Prophase I of Meiosis
Homologous chromosomes line up side by side during *synapsis*
Classify the following diseases - *Huntington's disease - color-blindness - hemophilia - cystic fibrosis*
Huntington's disease → autosomal dominant cystic fibrosis → autosomal recessive Color-blindness → X-linked recessive hemophilia → X-linked recessive
What are the 3 types of cartilage?
Hyaline, elastic, and fibrous
RP-HPLC
In Reversed Phase - (RP-HPLC) - stationary phase is a non-polar compound and the mobile phase is a polar solvent ELUDE FIRST - Polar (eg Water, Silica) - longer retention time ELUDE LAST - Non-Polar (eg Hydrocarbons) - longer retention time
Mechanism of TLC
In TLC, the tested sample is dissolved in an organic solvent and a small amount is spotted onto the stationary phase (commonly a polar silica [SiO2]) coated on a TLC plate. After spotting, the TLC plate is placed in a solvent chamber, and the mobile phase (organic solvent) travels up the plate and carries the spotted compounds along at different rates, which separates the mixture components. *Non-polar compounds have less affinity for a polar stationary phase and will travel further up the plate than polar compounds.*
Difference between ...
In mass spectrometry, - a sample is ionized by high-energy electrons, but the electrons *do not change energy levels* In TLC, - a UV chromophore sample is excited by high-energy electrons of the UV light, and the electrons *change energy levels to a higher energy state* In NMR spectroscopy - An external magnetic field is applied to a sample. Radio waves, which are low in energy, are used to detect hydrogen atoms and excite them from the *α spin to the β spin state*.
the product of mitosis
In mitosis the daughter cells are identical to the parent as well as to each other
biological structures contain _____ AA and ______ sugars almost exclusively
L, D
Almost all AA are synthesized in the ____ conformation
L-conformation
Northern blotting
Lab technique used to detect and measure concentration of specific *RNA molecules* within sample
Northern Blotting: Smaller molecules appear _____ than larger ones
Lower
What is Spermatogenesis - Male gamate; _____ is produced where - Describe it & function of the cells
Male gametogenesis - Male gametes (sperm) are produced --> in the seminiferous tubules of the testes Seminiferous tubules contains; 1) Sertoli cells (nurse cells) - provide nourishment to sperm & regulate development 2) Leydig cells - secrete testosterone in response to LH release from ant. pituitary
Reading a Mass Spectrometer
Mass spectrometry (MS) - separates ions according to their mass-to-charge ratio m/z. Assume a compound is 414g/mol - If the compound is singly charged (+1) after Mass spectroscopy, --> the MW (414 amu) of the initial molecule must be increased by the mass of one proton to 415 amu. --> Therefore m/z ratio is 415 on the mass spectrum. If the compound is doubly charged (+2) --> the MW (414 amu) of the initial molecule must be increased by the mass of two proton to 416 amu. --> Therefore m/z ratio is 416 on the mass spectrum.
Diff btw Mit and Mei
Mitosis is the process by which a cell divides to create two genetically identical daughter cells. However, during mitosis, homologous chromosomes do not pair up into tetrads and crossing over does not occur.
Mitosis Meiosis - Start with diploid/haploid - end with diploid/haploid, # and type of daughter cells
Mitosis- Interphase → 1(2n) →2(2n) - diploid/genetically identical daughters Meiosis- Interphase → 1(2n) →2(2n) →4(n) - haploid/genetically distinct daughters
Clone selection - Monoclonal antibodies - describe B & T proliferation b/4 and after attack
Monoclonal antibodies - are derived from a single clone & all recognize a single epitope on antigen --> sequester & inhibit action of antigen B and T cells that are specific for the antigen - aka - selected (as the key to the lock) - are cloned into an army of fighters & killers Before infection - B & T parent cells have DIFF daughter cells with diff antigens bearing diff variable portions for diff antigens After infection - The specific/selected/lucky B or T cell starts to differentiate/proliferate - B & T parent cells have all SAME daughter cells with same antigens bearing same variable portions for same antigens → so they can fight and kill same antigens
What is true of parallel beta-sheets?
N-termini of each strand aligned; adjacent backbones H+ bond with each other
Which immune cells respond to antigens by releasing toxins that induce apoptosis?
NK and cytotoxic T cells
Repolarization
Na+ channels close K+ channels open -K+ rushes out of the cell, causing membrane repolarization and restoring RMP
What causes depolarization of sarcolemma?
Na+ ions flows doen gradient, generates action potential along muscle fiber
Urinary retention in patients with poorly controlled diabetes mellitus is most likely the result of nerve damage impairing smooth muscle contraction in which of the following structures? - Bladder or IUS?
Nerve damage that impairs the contraction of the detrusor muscle of the bladder would impair emptying of the *bladder* and lead to urinary retention.
Describe the relationship between transition state and affinity
Part of induced fit theory: binding between enzymes and substrates is strongest at the corresponding reaction's transition state.
Phosphotases vs. Kinases
Phosphatases catalyze the dephosphorylation of their substrates by hydrolysis, producing inorganic phosphate. Kinases catalyze the phosphorylation of their substrates by transferring organic phosphate from a donor molecule, usually ATP. The two enzyme types often regulate biological processes by counteracting each others' effects.
Polygenic inheritance
Polygenic inheritance occurs when one characteristic is controlled by two or more genes. Often the genes are large in quantity but small in effect. Examples of human polygenic inheritance are height, skin color, eye color and weight.
Oogenesis
Process in which females produce sex cells. All woman's eggs are produced during fetal development. At birth their maturation is arrested in prophase I; these arrested cells are called primary oocytes. At start of menstrual cycle, each month primary oocyte develops into secondary oocyte by continuing meiosis up to metaphase II. During follicular phase of the cycle, follice(oocyte + granulosa cells) matures and grows driven by the release of FSH. LH causes follicle to rupture and release secondary oocyte near the opening of the fallopian tube(ovulation). Fertilization: creation of zygote and fallopian cilia propel zygote toward uterus for implantation.
Euchromatin
RELAXED chromatin, highly acetylated & transcriptionally active
RNA interference
RNA molecules inhibit gene expression or translation, by neutralizing targeted mRNA molecules
____ reads the noncoding DNA strand -> complementary mRNA transcript
RNA polymerase
Gel electrophoresis
Separates molecules by *molecular weight*, with LARGER ones migrating more SLOWLY
Sex-linked traits
Sex-linked traits - arise due to the expression of alleles present on an organism's sex chromosomes. Because the X chromosome contains significantly more genes than the Y chromosome, the majority of sex-linked traits are linked to the X chromosome. - Due to sex determination, male offspring (XY) receive their X chromosome from their mother (XX) and their Y chromosome from their father (XY). - Because males have only one X chromosome and cannot compensate with another, males in a population generally express recessive X-linked traits in higher proportions than their female counterparts.
Initiation
Small 40S ribosomal subunit binds mRNA 5' cap to scan mRNA for start codon (*Met, AUG*)-> tRNA brings anticodon
Which muscle type is NOT striated?
Smooth muscle
ascending loop of henle
Sodium (Na+), potassium (K+) and chloride (Cl−) ions are reabsorbed from the urine by secondary active transport by a Na-K-Cl cotransporter. The electrical and concentration gradient drives more reabsorption of Na+, as well as other cations such as magnesium (Mg2+) and calcium (Ca2+).
Spermatogenesis
Starts puberty, never ends, @Testes, cells of *equal* size, makes *4 haploid sperm cells*
Non-hydrolyzable lipids
Steroids, prostaglandins, fat-soluble vitamins
Example
Sterols are nonpolar compounds that dissolve best in nonpolar solvents within the organic layers of each extraction. Funnel A has chloroform (non-polar 1.5g/ml) Funnel B has ethyl acetate (non-polar 0.9g/ml) - However, the organic layers are in different positions Assuming density of water = 1g/ml chloroform is denser than the aqueous phase ethyl acetate is less dense than the aqueous Consequently, - In funnel A sterols settle in the bottom with chloroform, - In funnel B sterol settles at the top with ethyl acetate.
Techoic Acids
Teichoic acids are an important part of a Gram positive organism's cell wall and serve an integral function in the organism's adherence and penetrative properties.
Small intestine
The large intestine is not involved in large-scale nutrient digestion and absorption. In contrast, the brush border of the small intestine is a microvilli-covered epithelial surface where digestion and absorption of nutrients occur. The small intestine is composed of the duodenum, jejunum, and ileum. The duodenum is involved in additional digestion of nutrients, and the jejunum and ileum are involved in absorption of these nutrients.
pre-mRNA
Transcription is the process in which the nucleotide sequence of a DNA region is used as a template to synthesize a new RNA strand. (mRNA) is produced for the transcription of protein-expressing genes. Transcription begins with - the binding of transcription factors and RNA polymerase II to a specific AT-rich sequence (TATA box) in the promoter region of double-stranded DNA. - RNA polymerase II processes the noncoding DNA strand in a 3′ to 5′ direction until a termination sequence is recognized. - As the enzyme travels down the DNA strand, it unravels the DNA double helix and relies on the complementary pairing of bases to catalyze the synthesis of a pre-mRNA strand, which grows in the 5′ to 3′ direction.
Transformation
Transformation - occurs when prokaryotes pick up foreign genetic material from their surroundings. - Eukaryotes do not participate in transformation.
Hydrolyzable Lipids:
Triaglycerols, phospholipids, sphingolipids, and waxes (contain ester bonds; cleaved by *lipases*)
What happens when IUS or EUS are contracted during urination?
Urine is able to pass through the remainder of the urethra and out the body when the EUS is relaxed. - Inability to contract these muscles due to nerve damage would facilitate urine flow.
Route of concentrated urine from nepron → exit
Urine is concentrated in the nephron and moves from collecting ducts → renal calyces → renal pelvis, which marks the beginning of the ureter Ureter --> Bladder --> Urethra Renal calyces - First to collect urine from collecting tubules Ureter - is tube that connects the kidneys to bladder Urine is stored in the bladder until filled, after which it exits the body via the urethra in a process called urination.
antisense gene therapy
a gene silencing technique that acts by binding to the messenger RNA (mRNA) produced by that gene and inactivate it, effectively turning that gene "off". This is because mRNA has to be single stranded for it to be translated
somatostatin
a hormone that has a generalized inhibitory effect on digestive function and has been shown to suppress insulin and glucagon release.
binary fission
a kind of asexual reproduction. It is the most common form of reproduction in prokaryotes such as bacteria.
introns
a noncoding segment in a length of DNA that interrupts a gene-coding sequence or nontranslated sequence, the corresponding segment being removed from the RNA copy before transcription.
hybridization of genes
a phenomenon in which single-stranded deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) molecules anneal to complementary DNA or RNA
amitotic cell division
a simple method of cell division (also called direct cell division) which occurs without formation of spindle fibres and appearance of chromosomes
Implants in urethra for females
affect urinary function not reproduction
Crossing over
aka *recombination*, occurs during *prophase I* of meiosis, exchange of genetic info
Negative Selection/Central Tolerance - what happens? - How are they destroyed?
aka - Body attacking itself While developing in the bone marrow - if a specific antibody is able to bind to a protein (non-antigen) they consider their lock --> It means they are attacking self Negative Selection/Central Tolerance - process where immature B & T cells possessing receptors that bind to self-antigens (the good guys) present on the body's own cell are destroyed IOW - Body destroys lymphocytes producing antibodies that are specific for self-antigens Destroyed by - programmed cell death OR - by becoming unresponsive to antigens
leukocytes
aka WBCs: the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invader. leukocytes will flood into inflamed areas
0-5 ppm
alkane
Platelets
also called thrombocytes are a component of blood whose function is to stop bleeding by clumping and clotting blood vessel injuries. Mammalian platelets have no cell nucleus: they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow, and then enter the circulation.
adenylate cyclase
an enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP) and inorganic pyrophosphate (PPi ). It is activated by the attachment of a hormone or neurotransmitter to a specific membrane-bound receptor.
1700-1750
carbonyls
Gap junctions
cell-cell junctions that mediate communication between cells
midpiece of sperm
contains lots of mitochondria that allow it to move the flagella and then propel toward the oocyte. Also the it contains microtubules that allow it to be anchored to the cytoskeleton.
Leading strand synthesis is ____, whereas lagging strand is ____
continuous- leading discontinuous= lagging strand
Describe how cortisol, growth hormone, and glucagon impact blood glucose levels
cortisol = + glucose / growth hormone = + glucose / glucagon = + glucose
X-Ray Crystallography
crystalline molecule caused beam of x-rays to diffract into a pattern; can then find structure
Fully developed sperm has little of _____
cytoplasm; so reduction would not impact fertilization rate
how does decreased blood pressure impact reabsorption by the kidney?
decreased BP will decrease the glomerular filtration rate, allowing more time for reabsorption reabsorption
At high pH, proton concentration is low and amino acids tend to become ____
deprotonated
If pH > pKa
deprotonated
prostaglandins
derived from arachidonic acid and produce a localized inflammatory response Hormone produced by cells near affected area. Induces fever and inflammation. Aspirin blocks it.
Southern Blot
detect DNA
DNA sequencing
determine the nucleotide sequence of DNA *molecular technique used to determine the nucleotide order of DNA molecules. By analyzing the nucleotide sequences, DNA sequencing of whole genomes may be used to precisely quantify the copies of the VEGF gene present within a given tissue
What does blood vessel dilation due to maintain homeostasis at - different altitudes? - different temps?
dilation occurs at high altitude and higher temps. it allows increased blood oxygenation and heat radiation, respectively
Directional selection = one extreme preferred
directional selection, - one extreme phenotype is favored over all other phenotypes because of the additional fitness it confers. Consequently, the frequency of the related allele increases dramatically within a population.
positive control
display expected response
Constant region of antibodies
does NOT bind antigens
Bone and sex hormones
estrogen and androgen extend the life of osteoblasts and osteocytes and shorten the lifespan of osteoclasts. withdrawl of sex hormones leads to greater osteoclast than osteoblast activity diminishing bone mass
describe the role of estrogen in female fertility
estrogen helps the maturation of ovarian follicles. In addition, estrogens play an important role in regulation of gonadotropin secretion. For these reasons, estrogens are required for female fertility.
Splice acceptor sites
found at the 3' end of the itron *adjacent* to the exon
Characteristics of gap junction (4)?
gap junction must provide a low resistance electrical pathway that enables current to pass from one cell to the next 1. (cytoplasmic continuity) - joins cytoplasm of one cell to cytoplasm of next cell - why ATP and ions like Na⁺ can pass via channels 2. (Rapid transmission of ion potential) - When an ion potential reaches a gap junction, electric coupling between the 2 cells occur and the action propagates to the next cell (coupling) 3. (Coordination of muscle contraction in the heart) - coupling enables entire collections of cells to contract in a coordinated fashion
Native-PAGE
gel electrophoresis under non denaturing conditions; separates proteins by size w/o denaturing
positive pressure
greater than atmospheric pressure pressure travels from high to low
describe the relationship between blood pressure and urinary frequency
high BP = higher frequency remember via peeing during fight or flight
-vascular endothelial growth factor (VEGF) concentrations are lowest during the post-ovulatory secretory phase (when progesterone concentration is _______ ). *VEGF concentrations within peritoneal fluid may be inversely correlated with serum levels of progesterone.
highest,
Diaphysis
hollow shaft (medullary cavity) filled with bone marrow
protein hormones function via what mechanism?
interaction with transmembrane receptors
what type of dna is spliced out while forming mature mRNA?
introns
primary oocytes
is an immature ovum, or egg cell.The female germ cells produce a primordial germ cell (PGC), which then undergoes mitosis, forming oogonia. During oogenesis, the oogonia become primary oocytes. all primary oocytes are formed between fertilization and birth
cell cycle: S phase
is the part of the cell cycle in which DNA is replicated, occurring between G1 phase and G2 phase. Precise and accurate DNA replication is necessary to prevent genetic abnormalities which often lead to cell death or disease.
glomerular filtration rate
it estimates how much blood passes through the glomeruli each minute. Glomeruli are the tiny filters in the kidneys that filter waste from the blood
how does inbreeding reduce the fitness of a population?
it increases the incidence of expression of deleterious recessive traits
what does the direction of signaling mean if X ---> Y in a 2 cell embryo
it means that X, when isolated will have the same fate regardless of Y's presence
sympathetic NS activation
it will cause dilation of the blood vessels
Reduced ventricular filling would lead to....
less blood being expelled from ventricle with each contraction; decreased CO
The # of mutations increases _____ with time
linearly
Osteoporosis
loss of bone density
Genes that are located close together have...?
lower % of being separated by recombination than those that are far apart
negative pressure
lower than atmospheric pressure - responsible for the inflation of the lungs
which hormone triggers ovulation?
luteinizing hormone
Bacteria are removed from lymph and blood in the: _____ and ______
lymph nodes and spleen
when do centromeres split in mitosis vs meiosis
mitosis: anaphase I meiosis: anaphase II
UV Vis Spectroscopy
molecules w/ conjugated pi bond absorb; if more conj pi bonds, absorbs lower energy light; observed opposite color that is absorbed
Compared with healthy individual's ECG, the patient's ECG shows _____ waves of AV depolarization over the same time period. *increased # of APs fired from patient's SA and AV nodal cells, lead to ___ frequent atrial and ventricular contraction *depolarization and AP generation depend on Na+, Ca+ influx into cells -- more rapid influx of (+++) ions into SA nodal cells lead to ___ APs firing from SA node and ___ frequent atrial contraction
more, more, increased, more
describe uneven division during meiosis
most of the cytoplasm goes to the daughter cell destined for the ovum while little goes to the polar bodies. there's also uneven division of macronuclear dna
sarcoplasmic reticulum
muscle fiber organelle that tightly regulates intracellular calcium concentration
juxtamedullary nephrons
nephrons with well-developed loops of Henle that extend deeply into the renal medulla
ectoderm gives rise to
nervous system, skin, lens of the eye, etc.
crossing over only takes place in what method of reproduction?
occurs between prophase 1 and metaphase 1 the process where homologous chromosomes pair up with each other and exchange different segments of their genetic material to form recombinant chromosomes.
Transformation:
occurs when prokaryotes pick up foreign genetic material from their surroundings. -Eukaryotes=transfection
oxidative stress
occurs when there are too much reactive oxygen species
the product of meiosis
one diploid cell produces 4 haploid cells i.e. having half the chromosome number than the somatic cell of same organism. homologous chromosomes separate, leading to daughter cells that are not genetically identical
Autosomal Dominant disorder
only *one* copy of dominant allele necessary to produce phenotype
lipid rafts
ordered portions of the membrane high in cholesterol content
Describe the relative activity of osteoblasts and osteoclasts when experiencing bone loss
osteoblast↓ (decreased formation) osteoclast↑ (increased breakdown)
What is osteoclast & osteoblast? - How does menopause affect bone density?
osteoclast - breakdown of bone osteoblast - formation of bone estrogen and progesterone maintain bone mass by helping balance the rate of osteoclast/osteoblast activity to prevent porous, fragile bones Removal of E/P →↑osteoclast; ↓osteoblast = ↓ bone mass
Disulfide bonds can form in ___ conditions
oxidizing
Regulation of respiratory rate is most sensitive to:
pCO2 in the blood (pH of the blood), measured by chemoreceptors
the collecting duct
participates in electrolyte and fluid balance through reabsorption and excretion, processes regulated by the hormones aldosterone and vasopressin (antidiuretic hormone).
Sera
plural of blood serum It does not contain white or red blood cells or a clotting factor. It is the blood plasma without the fibrinogens. Serum includes all proteins not used in blood clotting (coagulation) and all the electrolytes, antibodies, antigens, hormones, and any extra substances such as drugs and microorganisms)
A measurement is ____ if similar results obtained on repeated trials
precise (reliable)
P-Value:
probability of observing a result due to change alone, assuming that the null hypothesis is true.
Western blotting
procedure that uses labeled antibodies to detect specific antigens in a mixture of proteins separated according to their molecular weight
natural selection
process whereby organisms better adapted to their environment tend to survive and produce more offspring.
pancreatic alpha cells
produce glucagon
pancreatic beta cells
produce insulin
pancreatic delta cells
produce somatostatin
fusion proteins
proteins created through the joining of two or more genes that originally coded for separate proteins
Recombinant proteins
proteins that are formed from genes that are inserted into cells that are different from the original cells that coded for and made the protein
If pH < pKa
protonated
Which event precedes the power stroke (motion of myosin head, pulling actin inward to shorter sarcomere)
release of ADP and Pi from the myosin head
norepinephrine function
released by sympathetic NS in fight or flight. increases heart rate and blood pressure, triggers the release of glucose from energy stores, increases blood flow to skeletal muscle, reduces blood flow to the gastrointestinal system, and inhibits voiding of the bladder and gastrointestinal motility.
Norepinephrine and epinephrine
released by the adrenal medulla to modulate the metabolism of glycogen. both hormones promotes glycogenolysis by inhibiting enzymes that mediate glycogen synthesis. also inhibit glycogenesis
deamidation
removes amides produce ammonia that is excreted as urea amido groups found in side chains glutamine and asparagine
deamination
removes amines, usually from backbone of amino acid produces ammonia that is excreted as urea
acetylcholine function
responsible for much of the stimulation of muscles, including the muscles of the gastro-intestinal system. It is also found in sensory neurons and in the autonomic nervous system, and has a part in scheduling REM (dream) sleep.
SDS-PAGE
runs gel electrophoresis under denaturing conditions; gives all proteins same charge so separates on mass alone; only breaks non covalent bonds (i.e not sulfide bridges)
Kidney's main functions
salt/H20 balance of blood; BP, waste removal, blood pH and *erythropoietin production*
Proline differs from AA in that it contains a ____ in backbone
secondary amine
Osteoclasts
secrete acids that breakdown mineral components of bone, releasing Ca2+/PO4 into bloodstream
Parietal Cells
secrete hydrochloric acid (HCl) and intrinsic factor. this allows pepsinogen (from chief cells) to become pepsin.
Gel-Filtration (size exclusion) Chromatography
separates based on size; have porous beads; smaller molecule take a longer path so elute later
Simple Distillation
separates by bp by boiling then condensing; used if bp's differ by 25 C or more
Fractional Distillation
separates by bp; used if bp's differ by less than 25 C; more accurate than simple distillation
Why would kidney failure occur as a result of dehydration?
severe dehydration will result in inadequate blood volume for effective filtration by the nephron
Morphogen
signaling molecule that alters embryonic cell differentiation in *concentration-dependent* manner
blood vessels have what type of muscle?
smooth muscle
D-Cells
somatostatin-producing cells. They can be found in the stomach, intestine and the pancreatic islets. ... Ghrelin can also strongly stimulate somatostatin secretion, thus indirectly inhibiting insulin release
Eukaryotic post transcriptional modifications
some eukaryotic RNA must be modified before being translated: Some pre-mRNA must have ends modified: 5' cap(modified Guanine) or 3' poly-a tail, protect the mRNA Splicing: introns(junk sequences) are removed and exons are stuck back together Leads to mRNA, increased stability
Transverse (T) tubules
specialized muscle fiber structures that facilitate *action potential* propagation in muscle fibers
Sarcoplasmic reticulum (SR)
specialized smooth ER responsible for regulating Ca2+ levels within muscle cell
Developmental pathway of fertilization of egg by sperm
spermatogium divided to daughter cells (spermatocytes) and then divides into spermatids after meiosis 2. After that it develops into spermatozoa once it loses most of the cytoplasm, acrosomal formation around the nucleus, mitochondrial around the center piece, and development of the flagellum
Oogenesis
starts prior to birth, stops @menopause, ovaries, monthly, cells unequal size, makes *1 haploid ovum + 2-3 polar bodies*
Stroke volume equation
stroke volume = end diastolic volume - end systolic volume
Charge on Phospholipids determined by ____?
structure of polar heads; phosphate component can be linked to various chemical groups
Complex 2 of ETC is also known as characteristics?
succinate dehydrogenase; succinate-ubiquinone reductase part of both the citric acid cycle and the ETC does not pump protons
glial cells
support the growth and function of neurons in the central and peripheral nervous system. Astrocytes, Oligodendrocytes, and ependymal cells are all types of glial cells.
Neural Crest cells act as
temporary migratory cells that give rise to diverse lineage of cells
Benedicts Test
test for reducing sugars; uses copper which will precipitate out and appear red if positive
Tollens Test
test for reducing sugars; uses silver ammonium nitrate which will precipitate out if positive
Fehling's Test
tests for reducing sugar; also uses copper which will appear red / precipitate out if positive
G-Cells
the G cell (or γ-cell) is a type of cell in the stomach and duodenum that secretes gastrin. It works in conjunction with gastric chief cells and parietal cells.
What phase does DNA replication occur in during the cell cycle?
the S phase
what is resorption?
the absorption into the circulation of cells or tissue.
what is the primary process that takes place in the colon?
the absorption of water
sarcomere structure
the actin microfilaments are capped by Z lines
polyadenylation
the addition of a poly(A) tail to a messenger RNA. The poly(A) tail consists of multiple adenosine monophosphates; in other words, it is a stretch of RNA that has only adenine bases. In eukaryotes, polyadenylation is part of the process that produces mature messenger RNA (mRNA) for translation.
sense vs antisense
the anti-sense strand acts as a template for mRNA
pulmonary artery
the artery carrying blood from the right ventricle of the heart to the lungs for oxygenation.
cancer is typically a result of which structure being damaged, at a minimum
the chromosome
Serum
the clear yellowish fluid that remains from blood plasma after clotting factors (such as fibrinogen and prothrombin) have been removed by clot formation
Cell Cycle: G1
the first of four phases of the cell cycle that takes place in eukaryotic cell division. In this part of interphase, the cell synthesizes mRNA and proteins in preparation for subsequent steps leading to mitosis
lymph
the fluid that circulates throughout the lymphatic system. The lymph is formed when the interstitial fluid (the fluid which lies in the interstices of all body tissues) is collected through lymph capillaries.
synapsis
the homologous pairing of chromosomes that occurs during prophase 1 of meiosis
which phase of the ovarian cycle has the highest level of progesterone?
the luteal phase
thyroxine
the main hormone secreted into the bloodstream by the thyroid gland. It plays vital roles in digestion, heart and muscle function, brain development and maintenance of bones.
Epitope
the part of an antigen molecule to which an antibody attaches itself
where is ATP synthase found in bacteria?
the plasma membrane
osmotic pressure
the pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution by osmosis, often used to express the concentration of the solution.
bacterial transduction
the process by which DNA is transferred from one bacterium to another by a virus. It also refers to the process whereby foreign DNA is introduced into another cell via a viral vector
Transamination
the process of transferring the amine group from one amino acid to another in order to manufacture a new amino acid converts essential AA to nonessiential AA
Cell Cycle: G2
the second subphase of Interphase in the cell cycle directly preceding mitosis. It follows the successful completion of S phase, during which the cell's DNA is replicated.
endoderm gives rise to
the stomach, the colon, theliver, the pancreas, the urinary bladder, the epithelialparts of trachea, the lungs, the pharynx, the thyroid, the parathyroid, and the intestines
Peptide bonds under physiological conditions are...
thermodynamically unstable, but kinetically stable
alveoli
tiny sacs within our lungs that allow oxygen and carbon dioxide to move between the lungs and bloodstream. it gives O₂ to the blood and receives CO₂ from the blood if an artery that supplies blood to the alveolus is blocked, alveolar PO₂ would increase and CO₂ would decrease
Squaline
triterpene (6 isoprene units)
radioactively labeled uracil is added to a culture of actively dividing mammalian cells. In which of the following cell structures will the uracil be incorporated? A) chromosomes B) ribosomes C) lysosomes D) nuclear membrane
uracil would be likely to be found in ribosomes because uracil is a component of RNA. chromosomes would contain DNA
Liquid Chromatography
use silica (polar) stationary phase and non polar mobile phase
Affinity Chromatography
used a specific ligand; proteins will separate based on their affinity to that specific ligand
Salting Out / Dialysis
used for protein purification; place protein sample in bag in buffer; bag is only permeable to small molecules which will move out of bag to buffer; then remove bag which will be more pure
Vacuum Distillation
used if bp's are high and risk changing chemically; use vacuum to reduce ambient pressure and thus bp's
Rf Value
used in TLC; = distance traveled by compound / distance traveled by solvent gront
Sanger Sequencing
used to determine DNA sequence; nature DNA; add ddnucleotides for replication; ddNTPs are fluorescent and stop replication; can then determine sequence
IR Spectroscopy
used to identify functional groups; only molecules w/ a dipole moment will show absorbance
Gas Chromatography
used to separate vaporized molecules; pass gas mobile phase through polar liquid stationary phase; polar molecules elute slower
Edman Degradation
used to sequence peptide; break off N-terminus amino acid then use chromatography to identify the amino acid; repeat up to 50 times
endoplasmic reticulum
where do postranslational modifications occur?
*GENETICS AND EVOLUTION*
*GENETICS AND EVOLUTION*
Notochord
*Mesodermal* cylindrical structure, releases signals promoting ectoderm to form neural plate
Anode
*positive* charge, low pH, attracts anions
- *region of DNA responsible for binding mRNA during prokaryotic transcription? - region of RNA responsible for binding ribosomes during prokaryotic translation?*
- *TATA box upstream Promoter region* with help of RNA Poly and TFs on mRNA strand - *Shine-Dalgarno sequence upstream start codon* on mRNA strand
*Diff between Conjugation, Transduction, Transformation & Transfection*
- Conjugation - Transfer of genetic info from one prok cell to another vis direct contact --> eg- F factor (sex pilus), plasmids (genes) -Transduction -Transfer DNA from one prok to another by bacteriophage - Transformation - Cellular uptake of foreign DNA from environment -eg- dead stuff - Transfection - Transfer of genetic material (plasmid) from Prok to Euks
Anaphase - Unique for? - what happens in mitosis and meiosis I and II - *what is non-disjunction?*
- Separation/ Non-disjunction Anaphase (mitosis) - No recombination - Sister Chromatids separate *(diploid)* Anaphase I (meiosis) - *After recombination* - Homo Chromosomes separate Anaphase II (meiosis) - No recombination - Sister Chromatids separate *(haploid)* Non-disjunction - occurs then sister chromatids fail to separate properly during anaphase → resulting in one daughter cell having unequal #s of chromosomes compared to others
pre-mRNA post-transcriptional modifications - 4 steps to mature mRNA
- occur at the non-coding (antisense) DNA strand in nucleus 1) 7-mGT (5'cap) is added to 5' end, 2) poly AAA tail is added to 3' end, 3) splicing done by spliceosome (snRNP + proteins) - introns removed and exons joined together 4) alternative splicing combines different exons to acquire different gene products from a single mRNA transcript - mature mRNA formed
Progesterone is secreted by? to maintain _____ In preparation for? What happens if pregnancy does not occur?
- the thick corpus luteum ( in ovary) → to maintain the uterine lining in preparation for an embyro - corpus luteum degenerates & progesterone levels fall as a new cycle starts
PCR reagents include what:?
-source DNA template -primer pairs -thermostable DNA polymerase -buffer solutions w/cations
Kidney function
1) Control of extracellular fluid volume & regulation of blood pressure via the renin-angiotensin system 2) Regulation of osmolarity (ie, excretion or retention of water) 3) Regulation of ion concentration (Na+, K+, Ca2+) by balancing dietary ion intake with urinary excretion 4) Regulation of pH via bicarbonate buffer system (excretion/retention of HCO3− and H+) 5) Excretion of waste (creatinine, ammonia, urea, foreign substances) 6) Production of renin (enzyme involved in blood pressure regulation) & hormones (erythropoietin for erythrocyte production & calcitriol for increased Ca2+ levels)
blood pressure is determined by
1) cardiac output 2) resistance to blood flow
2) Oligodendrocytes https://www.khanacademy.org/test-prep/mcat/organ-systems/neural-cells/v/oligodendrocytes
2) Oligodendrocytes = myelinate multiple nerves at their axons - form myelin sheaths around axons to reduce ion leakage, increase capacitance, and increase the speed of AP propagation along the axon. - - Each oligodendrocyte myelinates segments of multiple adjacent axons in the CNS - arise from ectoderm
how many nucleotides code for an amino acid?
3
6) Satellite cells
6) Satellite cells = structural support - provide structural support and supply nutrients to neuron cell bodies in sensory, sympathetic, and parasympathetic ganglia (groups of cell bodies). - They are thought to play roles similar to those of astrocytes in the CNS.
Transcription factors
Proteins that alter gene expression by binding DNA near gene promoter regions to either increase/decrease transcription
Dynein
A large contractile protein forming the side-arms of microtubule doublets in cilia and flagella.
Intramolecular vs Intermolecular Ortho vs para
A molecule that participates in strong intermolecular forces will have --> a higher b. pt than molecules with weak intermolecular forces. H-bonding can be - intermolecular (between two molecules) or - - intramolecular (within the same molecule), and therefore can have a significant impact on a molecule's boiling point.
nonsense mutation
A nonsense mutation - is a point mutation in which a single nucleotide change creates a premature stop codon, causing early translation termination and production of a truncated (shortened) protein.
Chargaff rules/pairing
AG - Purines CUT - Pyrimidines A=T - (less energy needed to break) G≡C (largest) G>A>T>U>C (smallest)
*Adrenal Hormones - found? - general function - types? - secrete? eg - function?*
Adrenal Hormones = On kidneys - Alter BP & allow body to respond to Stress 1) Adrenal Cortex = secrete corticostreroids a) Glucocorticoid (eg-cortisol) - ↑energy by stimulating gluconeogenesis (↑glucose), lipolysis (TAG breakdown), protein breakdown (proteolysis)/↓protein syn, ↓inflammation b) Mineralocorticoid (eg-aldosterone) - ↑homeostasis via Na⁺ reabsorption & excretion of K⁺ → ↑water retention → ↑BP due to ↑blood voume 2) Adrenal Medulla = secretes Epinephrine + Norepinephrine "fight or flight" - Mobilize body to deal with extreme stress by maximizing ↑blood flow to organs essential for survival
VEGF signaling also leads to the dilation of existing blood vessels. One function of vasodilation is to: A.increase body temperature in cold environments. B.increase blood flow to the intestines following a meal. C.decrease blood flow to the kidneys during dehydration. D.maintain blood pressure following an episode of fluid loss.
B.increase blood flow to the intestines following a meal.
Classification based on - morphology (shape) - habitat - O₂ dependence
Bacilli (rod) Cocci (spherical) Spirilli (spiral) Thermophiles (↑T°) Acidophiles (↓pH) Halophiles (↑Salt) Aerobic (O₂ needed) - Kreb, ETC (in Euk only) Anaerobic (No O₂ required) - Glycolysis, Fermentation, Glyconeogenesis, ETC (in Prok only)
What are the DECREASED conditions of Pulmonary gas exchange?
Blood leaving lungs has increased CO2 and decreased O2
What are the normal conditions of pulmonary gas exchange?
Blood leaving lungs has low CO2 and high O2
Oxidative stress occurs when:
Body unable to detoxify naturally generated reactive O2 species -> cell damage w/accumulation
Cofactors
Can be organic (coenzymes) or inorganic, can bind proteins tightly or loosly
Pluripotent cells
Can give rise to any of 3 germ layers in embryo, but NOT placental structures
Transcription Factors (TF)
Can upregulate or downregulate transcription by influencing ability of RNA polymerase to bind promoter
Conjugation
Conjugation - is the exchange of genetic information between prokaryotes, typically in the form of plasmid DNA. - It does not occur in eukaryotes.
distal convoluted tubule
DCT cells are rich in mitochondria, and possess the highest density of Na+/K+ ATPase along the nephron, where it is expressed on the highly amplified basolateral membranes. DCT cells are largely water impermeable, and reabsorb sodium and chloride across the apical membrane via electroneutral pathways.
Decarboxylation
Decarboxylation - is the removal of a carboxyl group with the release of CO2. - Forming a carboanion intermediate After formation of the carbanion, hydrogen is added --> results in a neutral compound
Changes in serum levels of ________ & ________ cause the physiological changes associated with the menstrual cycle
Estrogen & progesterone
Frameshift mutations
Frameshift mutations - result from the insertion or deletion of a number of nucleotides not divisible by three. These mutations change the reading frame of the transcript, giving rise to proteins with altered amino acid sequences
Tertiary & quaternary Interactions
Form through H+ bonds, salt bridges, hydrophobic, and disulfide bonds b/w AA *side chains*-> 3D folded formWu
_____amino acids are found on outside of proteins
Hydrophilic, interact favorably with H20 molecules
The degeneracy of the genetic code is due to which mechanism?
Nontraditional base pairing of anticodon with 3rd base of the codon
Penetrance
Penetrance - is defined as the proportion of individuals with a genotype who express the corresponding phenotype. complete penetrance When every individual with a specific genotype displays the associated phenotype incomplete penetrance When all individuals have the same genotype but only some express the corresponding phenotype - (eg, not all patients with the A3243G mtDNA mutation exhibit hearing loss
Penetrance (genetics)
Penetrance in genetics is the proportion of individuals carrying a particular variant (or allele) of a gene (the genotype) that also express an associated trait (the phenotype).
Proton nuclear magnetic resonance spectroscopy (1H NMR)
Proton nuclear magnetic resonance spectroscopy (1H NMR) - detects hydrogen atoms (1H isotope) in a molecule as an external magnetic field & radio frequency pulse are applied to the sample. The hydrogen atoms in different magnetic environments (resulting from molecular structure) are nonequivalent, and neighboring nonequivalent hydrogens within three bonds of each other cause spin-spin splitting of the peaks in the NMR spectrum. The splitting pattern can be determined by n + 1 rule, where n is the number of nonequivalent hydrogen atoms on adjacent carbons.
REPRODUCTION
REPRODUCTION
T/F: The resting membrane potential is restored by the Na+/K+ pump.
TRUE
Which blood types express A-antigen?
Types A and AB
nonsense mutation
a point mutation - a change in a single base pair - which creates a premature stop codon.
missense mutation
a point mutation in which a single nucleotide change results in a codon that codes for a different amino acid
Reverse transcriptase
a polymerase that catalyzes the formation of DNA using RNA as a template
the peritoneal cavity
a potential space between the parietal peritoneum (the peritoneum that surrounds the abdominal wall) and visceral peritoneum (the peritoneum that surrounds the internal organs).
glycogen
accumulated in response to insulin and broken down into glucose in response to glucagon. Glycogen is mainly stored in the liver and the muscles and provides the body with a readily available source of energy if blood glucose levels decrease
adaptive radiation
adaptive radiation = the divergence of species into multiple species over time. this occurs when subgroups of the OG species are separated or isolated in different environments so they can evolve independently of each other
Indirect ELISA
add primary antibody specific to protein of interest; then add secondary antibody specific to primary antibody; secondary antibody is bound to an enzyme that will change color; can then monitor absorbance
Oxidative muscle fibers use _____ respiration for ATP synthesis
aerobic, requires large amounts of O2 supplied by lots of myoglobin and extensive capillary networks
somatic cells
any cell of a living organism other than the reproductive cells.
carcinogen
any substance, radionuclide, or radiation that promotes carcinogenesis, the formation of cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes.
macronuclei
are polyploid and undergo direct division without mitosis or meiosis. It controls the non-reproductive cell functions, such as metabolism by providing proteins for the cell's day-to-day functioning
Which AA side chains contain amides?
asparagine and glutamine
D
aspartate
negatively charged amino acids
aspartate, glutamate (Glu)
glomerulus
bed of capillaries which receives blood from the renal arteries
Types of connective tissue
bone, blood, and adipose tissue
Describe the impacts of Calcitonin and Parathyroid Hormone on [Ca²⁺] in bone
calcitonIN: Ca²⁺ (out of the blood, INto the bone) parathyRoID: enhances the RIDDANCE of calcium from the bones - is inhibited by high levels of Ca²⁺
what is the impact of calcitonin on bone resorption?
calcitonin reduces Ca²⁺ levels in the blood by 2 mechanisms 1) It inhibits the activity of osteoclasts, which break down bone. 2) It decreases the resorption of Ca²⁺ in the kidneys, leading to lower blood calcium levels.
Infertility in patients with endometriosis can result from ectopic endometrial tissue deposits in:
canal, ovaries, fallopian tubes (not urethra)
10-13 ppm
carboxylic acid
freshwater fish osmoregulation
during osmoregulation, this fish takes on too much water so the kidney works to get rid of all the excess water by making diluted urine *Gain H2O, Lose Na+
proximal convoluted tubule
functions especially in the resorption of sugar, sodium and chloride ions, and water from the glomerular filtrate
not having a genotype selected against is equivalent to...
having equal fitness
components of sperm cell
head- acrosome + nucleus midpiece- mitochondria + microtubules tail- microtubules
Cardiac output is dependent on what 2 factors?
heart rate and stroke volume
NMR Integration
height of peak; shows number of equivalent hydrogens in a signal
increased blood pressure will have what impact on glomerulus?
increased glomerular filtration rate
aldosterone
increases reabsorption of Na⁺ and H₂O. this causes an increase in blood volume → blood pressure - released by the adrenal glands
ADH / Vasopressin
increases the amount of water reabsorbed in the distal convoluted tubule and collecting duct. ADH causes decreased urine volume and decreased plasma osmolarity
Splice donor sites
located in the 5' end of intron next to the exon
Ubiquitin tags
mark cytosolic proteins for proteasomal destruction
outbreed
mate with nonrelatives; seen in LARGER populations, more diverse
Kinesin motors move in what direction?
moves cargo along microtubules in *anterograde* axonal transport (away from nucleus, toward distal sites)
kinesin
moves intracellular cargo along microtubules away from the nucleus and toward distal sites (anterograde)
dynenin
moves intracellular cargo toward the nucleus (retrograde)
Gel Electrophoresis
place protein / DNA / RNA in gel; apply current; negative molecules go to positive anode and vice versa; separates based on mass & charge
Induced fit theory:
substrate binding induces a change in the shape of the active site to accommodate the substrate.
Lock and Key theory:
substrates bind readily to enzymes because their active sites are already in the correct structural conformation.
why is mRNA turnover important?
turnover = degradation without mRNA degradation, there'd be continuous protein production
cardiac output
CO = stroke volume x heart rate
p-value that shows statistical significance?
P<0.05
Extraction
"Like dissolves like" is the driving principle for extraction procedures. During extraction, two immiscible solvents (solvents that cannot mix) can be used to separate solutes (dissolved particles) according to differences in polarity.
Given a homodimer with 225 residue monomer - Calculate # of AA residues - Calculate # of nucleotides in mRNA sequence - Calculate molecular weight of the protein
# of AA residues = 225 x 2 = 450 total AA # of nucleotides in mRNA sequence = # AA in protein × 3 nucleotides per codon = 450 AA × 3 nucleotides = 1,350 nucleotides molecular weight of the protein = # AA in protein × molecular weight of an AA = 450 AA × 110 Da = 49,500 Da 1350 mRNA nucleotides must be translated to form 50,000Da or 50kDa protein
Diff btw (Proto) Oncogenes, Tumor suppressing cells and Pro-apoptotic proteins - what do they code for? - what do they promote? - what do they inhibit?
(Proto)-Oncogenes eg p53, Rb - code for cell growth factors or receptors - mutated or over-expressed gene that induces uncontrolled cell growth - by promoting cell cycle progression or inhibiting apoptosis Tumor suppressing genes - code for DNA repair enzymes. - repress uncontrolled/cancerous cell growth via apoptosis In cancer; ↑Oncogenes; ↓Tumor suppressing genes → Ignores Apoptosis pathways Pro-apoptotic proteins - would not lead to DNA repair, but would prevent tumor development via apoptosis (cell death pathways)
TLC, UV light and Chromophores
(TLC) is a useful technique to monitor reactions - Ultraviolet (UV) light can be used to visualize the results from TLC if the components from the reaction mixture can absorb UV light. UV light carries a large amount of energy that can excite the electrons of UV chromophores to a higher energy state. *Absorption of ultraviolet (UV) light induces electron excitation, and a compound must contain a UV chromophore to absorb UV light*. *UV chromophores include - double and triple bonds, - carbonyls (C=O), - nitroso groups, - alkyl halides, and - conjugated systems - aromatic ring* *eg - The aromatic ring in 4-nitrophenol and 4-aminophenol is a UV chromophore, so each compound can absorb UV light and will appear on the TLC plate.*
*CELL GROWTH*
*CELL GROWTH*
*VIRUSES*
*VIRUSES*
Divergent evolution leads to...?
*unique* characteristics in *somewhat closely related* species that face *contrasting environmental* pressures.
- what kind of tissue is blood? - give other examples of connective tissues - where does blood originate, enzyme - 5 components of blood
- Blood is a connective tissue - other eg - bone - bone marrow by erythropoietic enzyme 1)Plasma-liquid portion (90% water,10% others) 2) RBCs - for O₂ transport 3) WBCs - for immune defense 4) Platelets - for blood clotting
Similarities btw sperm & egg Diff btw sperm & egg - Cell volume - Maturation stage at birth - Rate at which they are produced
- Both egg & sperm cells contribute same # of chromosomes to zygote during fertilization 1) Cell Volume; Sperm= smallest; egg = largest 2) Maturation stage at birth; - Testes-of newborns contain spermatogonium and mature to spermatocyte at puberty - Ovaries of newborn girls contain oocytes that are arrested at prophase I until puberty 3) Rate at which they are produced; - Males- millions of sperm produced daily after puberty - Females - are born with their full complement of oocyte & only a few mature during each menstrual cycle - 1/28 days
*Similarities*
- Both have double-stranded DNA - Both of their mRNAs can be *bound by multiple ribosomes* in the cytoplasm - Under anaerobic condition, → glycolysis, fermentation and gluconeogenesis are active in both Euks and Proks - Because no O₂ required - Krebs cycle and the ETC are only active in the presence of a final electron acceptor, such as O₂ (aerobic) or inorganic ions (anaerobic) - Both can reproduce sexually.
Where are the following regions found on a chromosome? - *Heavily methylated region* - Centromere - *Histone-rich region* - *G-C rich region* - *A-T rich region* - Telomere - p - q
- Heavily methylated region - Centromere = center - Histone-rich region = G-C (light bands) and A-T (dark bands) - G-C rich region = light band/less condensed /euchromatin region = transcriptionally active - A-T rich region = dark bands/condensed /heterochromatin region = transcriptionally inactive - Telomere = ends - p = short arm - q = long arm
Leukocytes - Types (5) - which are phagocytes? how do they attack? - which are innate, adaptive - which are APCs Monocytes lifespan? where? - then differentiate to? where
- Monocytes - innate - Neutrophiles - innnate - Lymphocytes - (B,T) adaptive, APCs - Basophiles - Eosinophiles Phagocytes = APCs - Neutrophiles, Macrophages, Dendritic cells - Monocytes circulate bloodstream for 1-3 day - then move into tissues viaout body where - they differentiate into *macrophages & dendritic cells*
Hardy- Weinburg assumptions
- No new mutations - No natural selections - No gene flow in and out - Random mating - Large population size When a population is in Hardy-Weinberg equilibrium, - allelic frequencies do not change from one generation to another. - As such, heterozygosity in Hardy-Weinberg equilibrium is neither decreased nor increased but remains the same over time.
If radioactively labelled cytosines was added to a culture in the middle of prophase, and then growth was halted at the end of telophase. Where would radioactively labelled DNA be found?
- No where - DNA is replicated in S phase. - Prophase is in M phase. Since all of the DNA that would be present at the end of telophase had already been synthesized in S phase, none of the cytosines would be incorporated into the DNA of any cells in the culture.
What is test cross? -* what does it determine? - what is crossed with what? - can it be used for all or any of these (monohybrid, dihybrid, or polyhybrid)*
- determines unknown genotypes of organism --> homo or heterozygote - unknown is crossed with known *homozygous recessive* individual, - can be used for monohybrid, dihybrid, or polyhybrid.
Replication Stress - where & when does it occur - how is it repaired?
- occurs when DNA synthesis is arrested(stops) at the S phase of Euk cell cycle ------------ X B/4 replication / After replication Replication Stress response factors - repairs stalled fork → to continues replication
Uncontrolled hyperglycemia (↑glucose) can damage the nerves that innervate urinary tract musculature, resulting in urinary retention - Administration of a SGLT inhibitor
- prevents glucose reabsorption - increasing solute concentration within the tubule and - consequently increasing the osmotic pressure of the tubular filtrate. - As a result, water is drawn back into the renal tubule, increasing urine output.
What are the approximate voltages inside the neuron in each phase? what happens in each phase? - Resting Phase - Threshold - Depolarization - Repolarization - Hyperpolarized aka? - when does absolute refractory period begin & end? - when does relative refractory period begin & end?
- resting membrane potential (RMP) = −70 mV. - depolarization (AP) - increases till it peaks at +40 mV - hyperpolarized - (AP) - drops to a more negative potential than −70 mV 1) Resting Phase - Na⁺ and K⁺ channels closed 2) Threshold - if reached, an AP is fired, if not- no AP is fired and the RMP is restored. 3) Depolarization - Na⁺ ions rush into the cell. up to +40 mV → Then Na⁺ channels closes and K⁺ channels open. - Also, voltage-gated Ca²⁺ channels opens - absolute refractory period begins 4) Repolarization - K⁺ ions rush out of the cell. - absolute refractory period ends 5) Hyperpolarized - until the cell overshoots the −70 mV level (temporarily) - relative refractory period begins - Na⁺/K⁺ pump gets back to work to re-establish the RMP state of cell.
Resting membrane potential (RMP):
-70mV (inside of the neuron is 70mV more negative than the extracellular space) -Maintained by the Na+/K+ pump & K+ "leak" channels which always allow passive diffusion of K+ ions across the membrane. -Ion channels are closed here
Multipotent cells:
-Able to differentiate onto the specialized cells of certain tissues -Found in adults
Threshold:
-An excitatory stimulus causes several nearby voltage-gated Na+ channels to open, allowing Na+ ions to rush into the cell. -the membrane potential becomes more positive than the RMP (ie, depolarized). If the neuron depolarizes to a certain threshold value, an AP is fired. -If the threshold is not reached, no AP is fired and the RMP is restored.
Depolarization
-At threshold, the remaining voltage-gated Na+ channels open, resulting in the rapid depolarization of the local membrane. -This rise in membrane potential triggers a positive feedback loop, opening more Na+ channels in adjacent segments to propagate the AP down the axon.
Genetic code: "Degenerate"
-Because more than one codon can code for the same amino acid. -This occurs because the third position of the mRNA codon and tRNA anticodon can undergo nontraditional base pairing, allowing a single tRNA molecule to bind different codons
Competitive Inhibitors:
-Bind enzymes at the active size--> increase amount of substrates needed to achieve Vmax--> increase Km
Allosteric effectors:
-Bind proteins at one site and induce a conformational change at another site.
Post-transcriptional modifications:
-Covalent additions of non-amino acid groups to proteins.
Hyperpolarization:
-Excessive K+ efflux causes the membrane potential to fall below the RMP (hyperpolarize) -the local membrane enters a refractory period (absolute or relative).
Allosteric activators:
-Increase the ability of the protein to function -Inhibitors decrease the function
Myelin sheath:
-Increases the speed of action potential propagation by acting as an electrical insulator that prevents dissipation of charge across the membrane.
Endoderm
-Innermost layer -Gives rise to accessory digestive organs (liver, pancreas) & lining of the digestive and respiratory tracts
Complete removal of the ovaries would most likely result in:
-Irritability, anxiety, fatigue -Breast atrophy (breast shrink) -Infertility -Decreased Bone Mass
DNA sequencing:
-Used to determine the nucleotide sequence of DNA -Can be used to determine relative gene count
Vasodilation:
-Widening of blood vessels -Increase blood vessel volume--> decrease BP -Increase BF to promote delivery of oxygen and nutrients to tissues supplied by that blood vessel.
vasoconstriction
-decrease blood flow -decrease diameter of superficial blood vessels. -increase blood flow
vasodilation
-increase blood flow -increase diameter of superficial blood vessels. -decrease blood flow
Juxtamedullary nephrons have ___ loops of Henle extending deep into the salty medulla to ____ water reabsorption *Cortical nephrons have ___ loops of Henle extending shorter distances into the medulla, making them ___ efficient at water reabsorption.
-long, maximize -shorter, less *Camels absorb more water in water-deficient environments -> camels have higher # of juxtamedullary nephrons & lower # of cortical nephrons
When acetylcholine (ACh) is released by the motor neuron at the neuromuscular junction:
1) ACh binds and opens ligand-gated ion channels in the sarcolemma (the plasma membrane of the muscle cell) 2) Na+ flows down its electrochemical gradient and into the cell through the channel, resulting in depolarization of the sarcolemma and generation of an action potential that propagates along the muscle fiber in all directions. 3) At certain locations along the muscle fiber, the sarcolemma burrows deep into the cells, forming a channel known as the transverse (T) tubule, which brings depolarizing current close to the sarcoplasmic reticulum (SR) (Choice B). The SR is a specialized smooth endoplasmic reticulum responsible for regulating cytosolic Ca2+ levels within the muscle cell. 4) Action potential propagation through the T tubule ultimately leads to the opening of Ca2+ channels in the SR membrane. Because Ca2+ is more highly concentrated inside the SR than in the cytosol, the opening of these channels results in Ca2+ flowing down its concentration gradient and into the cytosol. 5) Cytosolic Ca2+ ions then bind to troponin, which allows the actin and myosin filaments of the sarcomere to slide across one another. The sliding of the filaments results in shortening of the sarcomere and overall muscle contraction 6) The Ca2+ channels in the SR membrane close when the depolarizing stimulus ceases. Active transport Ca2+ pumps sequester the Ca2+ back into the SR, which allows the muscle to return to its relaxed state as cytosolic Ca2+ concentration falls
If 3rd line of defense - where does this occur? - which cell binds to antigen - what does it release? - what cell starts differentiating & cloning itself
1) Dendritic cells is attacked by foreigner in the cell OR - Cell becomes abnormal/cancerous 2) It engulfs, phagocytosize & degrades antigen → which are released into cytosol 3) MHC I presents degraded antigen on surface 4)*Tcyt* cells specific for that antigen binds to it & gets activated 5) B cells starts differentiating & cloning itself 6) Some B & Tcyt cells become memory cells and others become plasma/effector cells
Northern blotting = RNA
1) Load RNA samples unto gel and apply electric field 2) Transfer samples from gel to blotting membrane 3) Hybridize with probes and visualize results - Probe hybridize with target RNA
If 2nd line of defense - where does this occur? - which cell binds to antigen - what does it release? - what cell starts differentiating & cloning itself
1) Nucleophiles and macrophages attacks anything in site in the blood 2) they engulfs, phagocytosize & degrades antigen → which are released into blood 3)MHC II presents degraded antigen on surface 4)*Th* cells specific for that antigen binds to it & gets activated 5) Th cell releases cytokines to alert all other cells 6) B cells starts differentiating & cloning itself 7) Some B & Th cells become memory cells and others become plasma/effector cells
compare 10⁻⁷ and 10⁻⁶
10⁻⁷ and 10⁻⁶ differ by a factor of 10
1) Why is alveoli sac highly effective at gas exchange 2) Which ventricle have thicker/muscular wall & WHY? 3) A protein with with more AA sequence (680) in tissue & less AA sequence (661)in blood means ...
1) due to elastic structure & extensive surface area 2) L(ventricle) have thicker walls than R(ventricle) - because L(ventricle) must pump blood at higher pressure necessary to propel it to larger structures (all tissues except lungs) and across long distances in circulatory system 3) 19AAs make the signal sequence (in secretory pathway) →and can be found in the liquid portion of the blood aka plasma
Steps in Transcription (I,E,T) - start with topoisomerase, promoter region, RNA poly binding, directions, end with mRNA
1) helicase(unwind) and topoisomerase(-supercoil) the DNA double helix 2) TF and RNA Poly II bind TATA box in promoter region 3) As RNA Poly II travels down and reads DNA strand in 3' to 5' direction, it unravels double helix & relies on the complementary bases to catalyze the synthesis of pre-mRNA strand which grows in the 5' to 3' direction
Steps in Eukaryotic DNA replication - function of the ffg - topoisomerase II, helicase, ssDNA-BP, primase, DNA polymerases α + β, range h, DNA poly γ, DNA ligase - are telomeres synthesized? 5) DNA synthesized by _____ 6) RNA primers removed by _____ 7) RNA replaced with DNA by ______
1) supercoils removed by DNA topoisomerase II 2) helicase unwinds DNA strands 3) ssDNA-BP stabilize DNA & prevents reannealing 4) RNA primers synthesized by primase, 5) DNA synthesized by DNA poly α + β 6) RNA primers removed by range h, 7) DNA replaced with DNA by DNA poly γ, 8) okazaki fragments joined by DNA ligase, - telomeres synthesized by telomerase
Steps in prokaryotic DNA replication - function of the ffg - topoisomerase II, helicase, ssDNA-BP, primase, DNA polymerase III, DNA poly I, DNA ligase, leading and lagging strands - are telomeres synthesized? 5) DNA synthesized by _____ 6) RNA primers removed by _____ 7) RNA replaced with DNA by ______
1) supercoils removed by dna topoisomerase II 2) helicase unwinds DNA strands;disrupts Hbond 3) ssDNA-BP stabilize DNA & prevents reannealing 4) RNA primers synthesized by primase, 5) DNA synthesized by DNA poly III in 5' to 3' 6) RNA primers removed by DNA poly I, 7) RNA replaced with DNA by DNA poly I, 8) okazaki fragments joined by DNA ligase - leading - continuous toward rep. fork - lagging - discontinuous away from rep. fork - telomeres not synthesized
What happens when solute concentration in the body is increased?
1) ↑ Osmolarity 2) Hypothalamus detects ↑ solute conc and induces ADH release by posterior pituitary and thirst 3) ↑ Thirst and ADH levels 4) Person drinks water; increased water reabsorption from collecting duct
Triggers for the release of Renin
1) ↓B.P 2) Sympathetic Nerves cell firing 3) ↓ Na
pre-mRNA undergoes these modifications -> mature mRNA
1. 5' cap added (7-methylguanosine) 2. 3' poly-A-tail added 3. noncoding (introns) excised
Western Blot Procedure
1. Cells lysed and DNA contaminants are removed 2. Sample run using SDS-PAGE 3. Visualize protein bands on gel using stain such as Coomassie blue 4. Identify presence of a specific protein a. Current used to transfer proteins onto nitrocellulose sheet b. Membrane incubated in protein-specific antibody solution (antibody coupled to radioactive isotope) c. Labeled antibodies mark presence of the protein as a discrete band within a lane of the gel 5. Compare location of the protein on the blot to standardized protein ladder than highlights specific molecular weights in kD
Polymerase Chain Reaction (PCR)
1. Denaturation of DNA Template - separate double to single stranded DNA 2. Annealing - Add primer to single strand 3. Elongation by DNA Polymerase Step is 1-3 repeated for multiple cycles Measure DNA amplification
3 steps of translation
1. Initiation 2. Elongation 3. Termination
What helps maintain the RMP of a neuron?
1. Passive transport -presence of protein channels allows for passive transport of ions down electrochemical gradient 2. ATP -Active transport 3. Membrane selective permeability -Generates RMP in nerve and muscle cells.
three assumptions of Michaelis - Menten equation
1. free ligand approximation: [s] is constant during the reaction 2. steady state assumption: [es] is constant 3. irreversibility assumption: reaction proceeds only in forward direction
Aldosterone: impact on BP, synthesis location, site of action, mechanism?
1. increases BP (2) adrenal glands (3) distal tubule & collecting ducts (4) adds sodium channels to the tubular membrane for increased reabsorption of salt and water
- Line of defenses - Diff btw innate & adaptive
1st = barrier (skin, mucous, stomach acid, normal flora) 2nd = non-specific inflammatory response --> with help of phagocytes (Neutrophiles, Macrophages, Dendritic cells) 3rd = specific inflammatory response --> with help of lymphocytes (B & T cells) Innate = Not learned, non-specific target - 1st and 2nd line of defense Adaptive = Learned, specific target - 3rd line of defense
Diff btw 1st & 2nd line of defense for Negative Selection/Central Tolerance
1st Line of defense in bone marrow & thymus - Immature B&T that attack self are identified & immediately killed → to prevent them from getting to the lymph node (not fool proof) 2nd line of defense at lymph node - If B or T-cell attacks a self-antigen on ADC →It leads to auto-immune disease --> due to failure of immune system to identify & destroy them then
glycolysis produces how many ATP per glucose molecule?
2 ATP
Monoterpene
2 isoprene units
Hemoglobin's affinity for O2 is decreased in the presence of which enzyme?
2,3-biphosphoglycerate (2,3-BPG); binds hemoglobin at allosteric site and reduces O2 binding
Which compound remains in the reaction flask during the steam distillation? - 2-nitrophenol and 4-nitrophenol
2-nitrophenol and 4-nitrophenol are constitutional isomers but they experience different intermolecular forces, which contributes to the difference in their boiling points. 2-nitrophenol - OH and NO₂ groups are ortho (R1, R2) --> ie close in proximity to each other, - ∴ The H and N can H-bond intramolecularly - - *Intramolecular bonding decreases the number of intermolecular bonds that can form, thereby decreasing the b. pt of the compound* 4-nitrophenol - OH and NO₂ groups are para (R1, R4) --> ie NOT close in proximity to each other, - they are able to H-bond intermolecularly but not intramolecularly. - *Intermolecular bonds hold the molecules together, thereby increasing the b.pt & causing it to stay in flask while 2-nitrophenol distills*
3) Astrocytes (shaped like stars) https://www.khanacademy.org/test-prep/mcat/organ-systems/neural-cells/v/astrocytes
3) Astrocytes = Form blood-brain barrier - make extensive contact with blood vessels and regulate blood flow in coordination with synaptic activity and chemical changes. - Maintains the chemical homeostasis of the interstitial space, including regulation of fluid and ion balance, pH, and neurotransmitter concentrations. - Scaffold - Glial scar - Homeostasis - Blood-brain barrier - Clear synapses - arise from ectoderm
Hh x Hh phenotypes
3: dominant 1: recessive
For autosomal dominant inheritance, a heterozygous parent has _____% chance of passing mutation?
50% chance P(child with disorder)= (0.5)(0.5)= 0.25
The sequence below is a portion of exon 7 of the SMN1 mRNA transcript. 5′ - UCAAGUGAUUCUCCU - 3′ Which of the following represents the corresponding DNA coding strand sequence for this particular transcript?
5′ - TCAAGTGATTCTCCT - 3′ Sense (coding) DNA strand - 5′-TCAAGTGAT-3′ mRNA Strand - 5′-UCAAGUGAU-3′ AntiSense (non-coding) DNA- 3'-AGTTCACGA-5'
Ribosomal structure of Prokaryotes
70S ribosomes composed of 50S (large) + 30S (small) subunits
Ribosomal structure of Eukaryotes
80S ribosomes composed of 60S (large) + 40S (small) subunits
- Age of menopause - Surgical removal of ovaries (endometriosis) is synonymous with menopause; WHY? - what happens during this period? - What does ↓ estrogen and progesterone lead to?
>50 - No menstrual cycle - estrogen and progesterone ↓ leading to 1) vaginal dryness 2) mood swings 3) atrophy (reproductory organs & breast) 4) ↓ bone density 5) Infertility
methylation
A chemical modification of DNA that does not affect the nucleotide sequence of a gene but makes that *gene LESS likely to be expressed*.
dimers
A dimer - is a protein that is composed of two noncovalently bound polypeptide chains (also called subunits, or monomers). A homodimer - is a protein in which the polypeptide chains of the two monomers have the same sequence (number, order, and type) of amino acids (AA).
Ribose
A five-carbon sugar present in RNA; *pentose* and *furanose* form
Kinesin
A large family of motor proteins that uses the energy of ATP hydrolysis to move toward the plus end of a microtubule.
What make a reflex unique? Describe the reflex arc, neuronal pathway mediators in a reflex describe the 2 paths possible taken from when reflex impulses enter the spine till it leaves when is a motor neuron formed
A reflex = involuntary response to a stimulus that does not require input from the brain. Reflex arcs, neuronal pathways include; - sensory neuron, an effector neuron, and possibly an interneuron. Impulse enters the spine via the dorsal root ganglia and can be transmitted in one of two ways: 1) Directly to the effector neuron (ie, a monosynaptic reflex arc), or 2) Indirectly through an interneuron that interfaces with the effector neuron (ie, a polysynaptic reflex arc) Impulses leave the spinal cord via ventral root and travel along the effector neuron's axon to synapse with and stimulate a muscle fiber, gland, or ganglionic neuron. When the effector neuron synapses with a muscle fiber, it is referred to as a motor neuron.
A reflex arc https://www.khanacademy.org/test-prep/mcat/organ-systems/biological-basis-of-behavior-the-nervous-system/v/muscle-stretch-reflex
A reflex is an involuntary response to a stimulus that does not require input from the brain. Reflexes are mediated by reflex arcs, neuronal pathways that include sensory neuron, an effector neuron, and possibly an interneuron.
Pulmonary gas exchange facilitates the removal of _____ from the blood
CO2
Stenosis is the abnormal narrowing of a tubular structure in the body, such as a blood vessel. Stenosis of the afferent arterioles in the kidney would be expected to: A.decrease the glomerular filtration rate. B.increase blood flow to the glomeruli. C.decrease resistance in the afferent arterioles. D.increase output of urine.
A.decrease the glomerular filtration rate. *stenosis of the afferent arteriole would limit the amount of blood reaching the glomerulus, leading to decreased glomerular hydrostatic pressure and, consequently, a decreased GFR.
Main functions of ACh What neuromuscular diseases are associated with ACh deficiency?
ACh -muscle contraction; affect learning & memory - Deficiency = Alzheimer's disease & paralysis - Excess = Convulsions or excessive shaking Norepinephrine - arousal; fight-or-flight (also mood, sleep, & learning) - Deficiency = Depression - Excess = Fear, anxiety Dopamine - regulates emotions, ie reward sensation - Deficiency = Parkinson's disease - Excess = Schizophrenia Seratonin - affects mood, hunger,sleep, and arousal. - Deficiency = Depression, eating disorders, alcoholism, aggression - Excess = Tremors, headaches Endorphins - give feeling of well-being; euphoria or eliminate pain - Deficiency = Depression, anxiety - Excess = addiction (due to quick euphoria); opiate addiction (pain killing drugs)
After ADC presentation then what? - Scenario 1 = for extracellular pathogens - Scenario 2 = for intercellular pathogens - who recognizes and who doesn't recognize phagocytes
ADCs/Phagocyte moves to the part of the lymph node where the T-helper cells are Scenario 1 = for extracellular pathogens - Helper T cells recognize ADCs and sets off the alarm (release cytokines) - this activate more ADCs and B cells to attack and destroy foreigners Scenario 2 = for intercellular pathogens - Cytotoxic T cells recognize & signal for cell destuction B cells don't recognize phagocytes/ADCs - They need to be alarmed by Th to attack
ADH vs Aldosterone
ADH causes body to take up water (hypothalamus) Aldosterone causes body to take up salt and, in turn, causes water to follow (adrenal cortex)
Recombination
AKA: crossing over Occurs in prophase I of Meiosis. Can produce a new combination of alleles w/in a chromosomes by moving alleles from each chromosomes copy to another. The new combinations are called recombinant and the ones that existed are called parental. If two genes are located close together, they are relatively unlikely to be separated by a recombinant event.
Which of the following helps maintain the resting membrane potential of a neuron? Passive transport Adenosine triphosphate Membrane selective permeability https://www.khanacademy.org/test-prep/mcat/organ-systems/neuron-membrane-potentials/v/neuron-resting-potential-description
ALL OF THE ABOVE The resting membrane potential of neurons is primarily due to - the high concentration of (K+) and - the low concentration of (Na+) inside the cell as compared to the outside. The following mechanisms contribute to maintenance of the resting membrane potential: 1) potassium leak channels help maintain the membrane potential by enabling the passive transport (without using energy) of K+ out of the cell. 2) Active transport pumps hydrolyze (ATP) to provide energy to transport molecules against their concentration gradient. eg - (Na+K+ ATPase) transport 2 K+ into the cell for every 3 Na+ moved out of the cell. This is important for maintaining the unequal concentration of ions across the membrane; - - without active transport pumps, leakage of ions through the cell membrane would eventually result in equilibration and a membrane potential of 0 mV
sperm motility is dependent on
ATP
Acetylcholine (ACh), - associated with Sym and Parasym NS - Motor/Efferent Somatic NS (skeletal muscles) https://www.khanacademy.org/test-prep/mcat/organ-systems/neural-synapses/v/types-of-neurotransmitters
Acetylcholine (ACh), - a neurotransmitter, - plays an important role in the sympathetic and parasympathetic ANS. - ACh is the main neurotransmitter released by neurons of the efferent somatic nervous system, the system associated with skeletal muscle function. At the neuromuscular junction, - ACh is released via exocytosis from presynaptic motor neurons. - ACh binds to receptors on the motor end plate, triggering muscle contraction. Consequently, disruption of the release of ACh inhibits muscle contractions and causes skeletal muscle paralysis.
Prostaglandins
Act as autocrine/paracrine signals; produce *localized inflammatory response*
Difference between Adaptive radiation & Speciation
Adaptive Radiation = Darwin finches(diff beaks) - diversifying characteristics in a subgroup of individual from a single species - subgroup has a new role diff from others - BUT... can still mate with each other - ↓competition=↑fitness Speciation = New species - Adaptive Radiation gone wrong - New species from previously existing species - When species develop different characteristics (over many years) and get to a point that they become new species and - CANNOT mate with each other anymore
Adaptive radiation = aka Darwin's finches - different beaks for different functions
Adaptive radiation - is the process of diversifying characteristics in a subgroup of individuals from a single species. - It reduces intraspecific competition, the competition for resources by members of a single species. As a result, fitness is improved for the entire species because the subgroup has a new role within an ecological community (niche) that is different from the rest of the species. - Adaptive radiation can eventually lead to speciation, or the formation of a new species, if the subgroup continues to diverge. - and loses the ability to interbreed with individuals from the original species.
After extraction how do you precipitate DNA?
Add organic solvent Hydrophobic solutes such as lipids separate into the organic layer DNA remains in aqueous solution due to negatively charged phosphate groups (PO3−) on the sugar phosphate backbone To precipitate the DNA from aqueous solution, - its charge must be neutralized through extraction with ethanol and a salt such as sodium acetate. - Gentle mixing with ethanol disrupts the hydration shell around DNA molecules, so DNA can H-bond - *Sodium cations then neutralize DNA's charge via ionic bonding with phosphate groups, making DNA less hydrophilic, decreasing its affinity for the aqueous solvent, and allowing it to precipitate more efficiently.*
→ Adrenal hormones (Adrenal Cortex)
Adrenal cortex - Secrete Corticosteroid hormones 1) Glucocorticoids (eg, cortisol): Increase energy availability by stimulating lipolysis & gluconeogenesis (synthesis of glucose from noncarbohydrate sources such as amino acids); also, have anti-inflammatory effects 2) Mineralocorticoids (eg, aldosterone): Affect salt & water homeostasis in the kidneys by promoting sodium reabsorption & excretion of potassium - leading to increased water retention due to osmosis. Increased water retention increases blood volume, which in turn leads to an increase in blood pressure.
Stomach → Deodenum - what is expelled from the stomach to the deodenum after churning - describe it - name 2 secretions that neutralize it? where are they from? - what is the pH change?
After churning stomach expels - Chyme Chyme = partially digested food + gastric juice - acidic chyme passes into the → Duodenum - where it is neutralized by 1) the bicarbonate ions secreted from pancreas 2) the alkaline bile released from gallbladder. As a result, the pH of the chyme is increased to ~6.
Chyme from stomach (pH 1) to duodenum (pH 6)
After sufficient churning, the stomach expels - Chyme Chyme - is a semifluid mass of partially digested food mixed with gastric juice - The highly acidic chyme passes into the duodenum - where it is neutralized by 1) the bicarbonate ions secreted from the pancreas via the pancreatic duct and 2) the alkaline bile released from storage in the gallbladder. As a result, the pH of the chyme is increased to ~6.
Ribosome-mRNA complex - make up of ribosomes - *where does it translocate to and why?* - # of ribosomes for Proks and Euks
All ribosomes have (r)proteins + (r)RNA - translate mRNA sequence into proteins - translocate to rough ER to synthesize secretory lysosomal or integral membrane protein Euks = 60S+40S = 80S ribosomes Proks = 50S+30S = 70S ribosomes
Alternate splicing
Alternate splicing - produces multiple protein products from the same gene, not multiple similar genes. It's a process that allows various proteins to be generated from a single pre-mRNA transcript based on differential inclusion and exclusion of exons during splicing.
Extraction - Separation of Acids and Bases
Amides and carboxylic acids are polar, water-soluble molecules because they form hydrogen bonds in an aqueous solution. However, long alkyl side chains of amides and carboxylic acids increase the hydrophobic (nonpolar) nature of the molecules and make them insoluble in aqueous solvents. To separate long-chain amides from carboxylic acids in the organic layer, - a base must be added. - Bases deprotonate the carboxylic acid and generate carboxylate anions that are more soluble in the aqueous layer than the organic layer. Therefore, addition of the *strong base* LiOH will produce carboxylate anions that enter the aqueous layer and allow long-chain amides to remain in the organic layer.
Angiotensin II - what are the 2 ways it raises BP? Aldosterone - 2 triggers for release - how does it ↑BP? - jobs - goal ADH - 2 triggers for release - how does it ↑BP? - jobs - goal
Angiotensin II - ultimately raises BP by; 1) inducing the adrenal cortex (on kidney) to release *Aldosterone* --> Jobs 1: ↑Na⁺ reabsorption in kidney --> Jobs 1: ↑Water retention in kidney Goal = to ↑BP by increasing blood volume 2) causes posterior pituitary to release *ADH* --> Job 1: ↑Water retention in kidney --> Job 2:constrict the arterioles(↑resistance) Goal = to ↑BP without increasing blood volume Aldosterone - is released in response to RAS activation or to an ↑K⁺ (↓Na⁺) Aldosterone acts on the DCT and collecting ducts of nephrons → to ↑reabsorption of Na⁺ which leads to → ↑osmolarity, or solute conc → water reabsorption, →↑blood volume & ↑BP ADH - is released by the posterior pituitary when ↓BP or ↓blood osmolarity - ADH acts on DCT and collecting duct → to ↑water reabsorption - ADH also induces vasoconstriction → ↑BP
→ Anterior pituitary Hormones (FLATPEG)
Anterior Pituitary Gland made of glandular tissue 1) Follicle-stimulating hormone (FSH) - GnRH - Ovaries: Stimulates follicle maturation - Testes: Stimulates spermatogenesis 2) Luteinizing hormone (LH) - GnRH - Ovaries: Stimulates production of estrogen & triggers ovulation - Testes: Promotes synthesis of testosterone 3) Adrenocorticotropic hormone (ACTH) - CRH - Targets adrenal cortex to promote release of glucocorticoids 4) Thyroid-stimulating hormone (TSH) - TRH - Causes thyroid to release thyroid hormones (T3 & T4) 5) Growth hormone (GH) - GHRH - Targets a variety of tissues (eg, muscle, bone, liver) to promote cellular growth & degradation of fats 6) β-endorphins - CRH - Target opiate receptors in the brain to diminish pain perception 7) Prolactin - Decreased PIH - Stimulates lactation
Major types of hormones Major endocrine glands: names, locations, products
Anterior Pituitary Gland made of glandular tissue - FSH/LH = GnRH = Gonads = - ACTH = CRH = Adrenal Cortex(Kidneys) = Cortisol - TSH = TRH = Thyroid - Prolactin = Mammary Gland - Endorphins = - GH = GRH = Liver + Body Posterior Pituitary Gland made of Axon projections - ADH - Oxytocin Adrenal Gland - Top of Kidneys - Adrenal Cortex=Corticorticoid + Aldosterone - Adrenal medulla = Epinephrine + Norepinephrine Pancreas - Insulin + Glucagon = Liver Adrenal Cortex = Steroid Hormones/cholesterol - Glucocorticoid (eg cortisol) + - Mineralocorticoid (eg aldosterone) Adrenal Medulla = Amino Acid/Peptide Hormones - aka Catecholamines - Epinephrine + - Norepinephrine Sex hormones - testosterone - estrogen - progesterone
*Anterior Pituitary Hormones - made of ___ - 7 types - functions - what is secretion stimulated by? - which tissues do they target?*
Anterior Pituitary Hormones (FLATPEG) - made of glandular tissues 1) Follicle Stimulating Hormone (FSH) - secretion stimulated by GnRH - Ovaries - stimulate follicle maturation - Testes - stimulate sperm maturation 2) Luteinizing Hormone (LH) - secretion stimulated by GnRH - Ovaries - stimulate production of estrogen - Testes - stimulate production of testosterone 3) Adrenocorticotropic Hormone (ACTH) - secretion stimulated by CRH - Adrenal Cortex - release glucocorticoid & mineralocorticoid - Adrenal Medulla - release Epinephrine & Norepinephrine 4) Thyroid-Stimulating Hormone (TSH) - secretion stimulated by TRH - Thyroid - release thyroid hormones (T3, T4) 5) Prolactin - decrease PIH & stimulate lactation 6) Endorphins - secretion stimulated by CRH - Opiate receptors in Brain - diminish pain perception 7) Growth Hormone (GH) - secretion stimulated by GHRH - Variety of Tissues (muscle, bone, liver) - promote growth & degrade fat
Antibodies & Antigens - functions - who identifies, who kills antigens
Antibodies (Key) = specific; do not destroy, only identify/recognize with variable portion --> B cell does the killing Antigen (Lock) = foreigners; ↑MW; Antibody Main Part - Variable portion - bind to specific (matching) antigen floating around in blood (not in cell yet) & blocks them from getting to host cell → after binding B cells (plasma) gets activated & generate more similar antigens to kill
Apoptosis, or the programmed death of preexisting cells
Apoptosis, or the programmed death of preexisting cells, - limits the rate of cell proliferation. However, cancerous tumors develop as cells grow/divide uncontrollably and fail to follow predetermined apoptotic pathways. As a result, the fraction of apoptotic cells within a group of cancer cells is markedly decreased (inhibited). Educational objective: Apoptosis is the programmed and controlled death of aged, unnecessary, or damaged cells. Cancerous cells exhibit rapid and uncontrolled proliferation, which is caused by cell growth that outpaces normal apoptosis or by dysfunction of the apoptotic process itself.
AA that are negatively charged at physiological pH?
Aspartate (D) and glutamate (E)
Where does phosphorylation occur?
At the hydroxyl groups of serine, threonine, and tyrosine residues
Acetylcholine role:
At the neuromuscular junction, acetylcholine is released via exocytosis from presynaptic motor neurons. Acetylcholine binds to receptors on the motor end plate, triggering muscle contraction. Disruption of this process causes skeletal muscle paralysis.
Single-strand DNA-binding proteins (SSBPs)
Attach to separated strand to prevent spontaneous reannealing of unwound single-stranded DNA
Autosomal recessive conditions
Autosomal recessive conditions Father - A a (affected) Mother - A a - require the presence of two copies of the defective gene for disease manifestation and show no predilection for males or females. - About 25% (aa) of children are affected if both parents carry one copy of the defective gene (most common scenario).
Autosomal traits
Autosomal traits - arise due to the expression of alleles present on an organism's autosomes. - These alleles are passed to offspring through inheritance of the parental autosomes. Because males and females all have the same number of autosomes, autosomal traits are generally expressed in the same proportions in males as in females.
B and T Lymphocytes aka B and T cells - where do they start/mature/move to after maturity - type of immunity used - function of B cells - what do they become during and after attack - 3 types of T cells, CD, MHC and functions
B Lymphocytes - start out in bone marrow; mature in bone marrow - used in humoral immunity - generate antibodies - during attack; they become plasma cells; - after attack, they become memory cells T Lymphocytes - start out in bone marrow; mature in thymus - used in cell mediated immunity - during attack; they become effector cells; - after attack, they become memory cells 3 types of T cells 1) T-helper cells = CD4, bind MHC II; alarm other fighter to attack 2) Cytotoxic T cells = CD8, bind MHC I; directly destroy foreigner that have made it into the cell and cancer cells 3) Suppressor T cells After maturity; Both B & T move to lymph node where they wait till they are invaded/needed
Which statement most accurately describes the role of T tubules in skeletal muscle cells? A.T tubules bind acetylcholine at the neuromuscular junction to generate a depolarizing stimulus. B.Depolarizing current reaches the sarcoplasmic reticulum by traveling down T tubules. C.Muscle contraction is driven by the sliding of T tubules across one another in the sarcomere. D.T tubules sequester Ca2+ out of the cytosol to prevent prolonged muscle contraction.
B. depolarizing current reaches SR by traveling down T-tubules *For a skeletal muscle cell to contract, Ca2+ must be released into the cytosol from the sarcoplasmic reticulum (SR). Ca2+ release is induced when a depolarizing current (action potential) runs along the sarcolemma and travels down the T tubules. This current causes the nearby SR to open its Ca2+ channels, allowing Ca2+ ions to flow into the cytosol and induce the sarcomeric actin-myosin interactions required for muscle contraction.
Diff btw Bacteria, Archaea, Eukarya
Bacteria - Unicellular - Nucleus Absent - Organelles Absent - Cell wall with peptidoglycan Present - Cellular division by Binary fission - Circular Chromosome Archaea - Unicellular - Nucleus Absent - Organelles Absent - *No peptidoglycan cell wall* - Cellular division by Binary fission - Circular Chromosome Eukarya - *Unicellular or multicellular* - Nucleus Present - Organelles Present - No peptidoglycan cell wall - Cellular division by Mitosis - Linear Chromosome
Cervix
Barrier separating the vagina and uterus
ELISA
Based on the passage, enzyme-linked immunosorbent assay (ELISA) was used to quantify HIF-1α and HIF-1β protein concentration. In ELISA, samples are first added to a 96-well microplate, and the antigens (eg, proteins) become adsorbed (immobilized) to the surface of the well. A specific primary antibody linked to a "reporter" enzyme is then added to bind the antigen, as stated in the passage. The samples are washed to remove unbound antibodies, and the substrate of the reporter enzyme is added. The enzyme reacts with its substrate to generate ("report") a colored product, and if a color change is detected, its intensity is proportional to the amount of bound protein. Protein expression levels are ultimately quantified by comparing the color change in the well plate to the color change observed from a series of known concentration standards. Identifying a color change (minimal, medium, or intense) proportional to protein concentration would be a normal and accurate finding that indicates the presence and quantity of the protein.
Tumor suppressor genes
Based on the passage, regulation of p21 expression by c-Myc also contributes to B-cell lymphoma development in Eμ-Myc mice. In addition, the passage states that p21 inhibits cell cycle progression, - a key feature of a tumor suppressor gene. Tumor suppressor genes - regulate DNA repair by repressing or pausing the cell cycle to ensure that only normal cells proceed to the division stage and induce programmed cell death if repair fails. As a result, p21 levels would be lower in Eμ-Myc mice compared to wild-type mice because p21 was likely inactivated by loss of function mutations and lost the ability to prevent abnormal growth/division of cancerous cells. Compared to wild-type mice, c-Myc should be expressed more abundantly and p21 should be expressed less abundantly in Eμ-Myc mice.
Journey of the Sperm - where is sperm stored? - diff btw sperm in Spermatozoon stage & in epididymus Describe the human sperm cell
Basement membrane of seminiferous tubules (in testes) → lumen of seminiferous tubules → exit testes → epididymus → where they become motile & stored human sperm cell 1) Head = contain acrosome around nucleus → rich in enzymes used for piecing oocytes 2) Midpiece = contain mitochondria (ATP for motility) + microtubules (anchor for tail) 3) Tail/flagellum → wave-like swim to oocyte
Bile is synthesized in Bile is stored in Bile is released into ____ why? Bile is composed of Bile salts act as ____ why? - what is the process called?
Bile is synthesized in the Liver Bile is stored in the Gallbladder Bile is released into the intestine - to aid in the mechanical digestion of lipids. Bile is composed of - bile salts, - bile pigments (eg, bilirubin), and - cholesterol. Bile salts act as detergents to solubilize fats - therefore they break down large lipid globules into smaller droplets (micelles) in a process known as emulsification.
Composition of blood in pul veins & arteries - O₂; CO₂; H⁺ Describe systemic circuit & pulmonary circuit Describe gas exchange
Blood in pul veins (lung to heart)=↑O₂; ↓CO₂; ↓H⁺ Blood in pul artery (heart to lung)=↓O₂; ↑CO₂; ↑H⁺ Systemic circuit = carries oxy blood from heart to capillaries (in tissues) →gas exchange → brings deoxy blood back to heart Pulmonary circuit = pumps deoxy blood to the alveoli (in lungs) →gas exchange → brings oxy blood back to heart When oxy blood reaches capillaries (in tissues) - It delivers O₂ + nutrients → becomes deoxy → returns back to heart so it can enter pul circuit When deoxy blood reaches capillaries (in lungs) aka alveoli - O₂ diffuse from airsac to blood in lung (oxy) - CO₂ diffuse from blood in lung to airsac - Pul veins then return oxy blood to heart so it can be pumped via systemic circuit
What is blood pressure? - How does ↑ or ↓BP affect HR, blood vessels and blood volume?
Blood pressure (BP) aka Hydrostatic pressure -is the force exerted by blood on vessel walls - it pushes fluid via the pores of the capillary wall into the interstitial fluid (the extracellular fluid surrounding cells of a tissue). ↓BP = ↓HR → due to Vasodilation - blood vessels dilate → ↑blood flow, OR - when blood volume decreases. ↑BP = ↑HR → due to Vasoconstriction - blood vessels constrict → ↓blood flow, OR - when blood volume increases.
Bottlenecks = Not by chance
Bottlenecks - is the drastic reduction in population size that occurs in response to some sudden and uncontrollable disaster - due to environmental events (eg, flood, famine, human-induced catastrophe) or human action (human-induced catastrophe) - greatly reduce the genetic diversity of a population. Consequently, a smaller population has a reduced ability to buffer the negative impacts of random changes in allele frequencies (genetic drift) that may result in extinction.
MNEMONIC: Skin layers
Boys Says Girl Looks Cute (BOTTOM -> TOP) stratum basale stratum spinosum stratum granulosum stratum lucidum stratum corneum
CIRCULATORY & RESPIRATORY SYSTEMS
CIRCULATORY & RESPIRATORY SYSTEMS
Excess fluid in the patient's lungs is most likely caused by which of the following at the pulmonary sites of gas exchange? A.Increased protein concentration in the blood flowing through pulmonary capillaries B.Decreased osmotic pressure in the interstitial fluid surrounding the pulmonary capillaries C.Increased hydrostatic pressure within pulmonary capillaries D.Decreased volume of blood flowing through the pulmonary capillaries
C. Increased hydrostatic pressure within pulmonary capillaries *Pulmonary edema * increase in hydrostatic pressure exerted on capillary walls -> High hydrostatic pressure would increase the rate of fluid leakage into the interstitial space surrounding pulmonary capillaries, causing excess fluid accumulation in the lungs.
If a viral antigen were to bind to the receptors on the surface of a B lymphocyte, which of the following immune responses would NOT occur? A.Division of the B lymphocyte into cells that differentiate to secrete antibodies B.Interaction of the B lymphocyte with other immune cells that stimulate B-lymphocyte proliferation C.Secretion of toxins by the B lymphocyte that destroy nearby virus-infected cells D.Proliferation of cells that can recognize the antigen more rapidly in the event of a future infection
C.Secretion of toxins by the B lymphocyte that destroy nearby virus-infected cells *This produces many identical B lymphocytes that may differentiate into either of the following cell types: -Short-lived plasma cells secrete antibodies during the immediate immune response. -Long-lived memory cells remain in lymphoid tissues for a long time and can recognize the antigen more rapidly in the event of a future infection.
Which muscle type(s) has gap junctions?
Cardiac and smooth
What is cell determination? - what is it due to? What is cell differentiation? - what is it due to? What is inductive signaling? - how does it occur? why? what is the goal of cell transplant
Cell Determination - Specification of cell fate -due to inductive signaling btw cells in embryo Cell Differentiation - Acquisition of unique/specialized/biochemical/structural/ cellular characteristics in the embryo - due to inductive signaling Inductive signaling = communication with surrounding cells - occurs when an inducer/signaling cell releases chemical signals that act on neighboring cells by regulating the expression of specific genes - signaling provides the cell with positional & fate determining info required for proper development. During cell transplant - Goal is to determine whether donor neural cells would continue to develop independently → into the tissue of choice OR →assume a diff tissue type or cell fate (due to communication with surrounding cells aka inductive signaling)
What are the 2 Nervous System cell types? functions? - what are the CNS & PNS glial cells & functions - does Neural crest cells have inductive or inhibitory influence on Neural tube formation? - what happens when a disease (eg spinal bifida) affects the neural tube dev? how dos it affect neural crest
Cell Migration in embryogenesis - movt of cells into their final positions within the embryo - eg- Neural tube → give rise to CNS - Neural crest → give rise to PNS Nervous System cell types 1) Neurons - conduct electrical signals 2) Glial - Support neural functions CNS glial cells that arise from neural tube - Oligodendrocytes - form myelin sheaths around neurons - Astrocytes - provide support, anchor neurons to nutrient supply source PNS glial cells that arise from neural crest - Schwann cells - similar to Oligodendrocytes - Satellite cells - similar to Astrocytes Neural crest cells have no substantial inductive or inhibitory influence on Neural tube formation ∴ when a disease (eg spinal bifida) affects the neural tube dev, Neural crest cells are not involved in the pathology & will continue to act normally as temporary migratory cells that give rise to diverse lineages of cell in PNS
B lymphocytes*
Cells that bind and ENGULF a foreign antigen
Definitions of endocrine gland, hormone
Cells with paracrine function secrete substances to exert an effect on neighboring cells. In comparison, cells with endocrine function secrete hormones into the bloodstream to cause an effect in a different part of the body. Endocrine glands modulate physiological activity via the secretion of hormones Hormones can be classified by their modes of actions. - Tropic hormones regulate the secretion of other hormones by acting on other endocrine glands. - Direct or nontropic hormones act directly on nonendocrine tissues to cause physiological end points. The anterior pituitary releases both tropic (FSH, LH, ACTH, TSH) and direct (GH, prolactin, endorphins) hormones, whereas the posterior pituitary releases direct hormones (oxytocin, ADH).
Phospholipids in cell membrane can be separated based on what factors?
Charge, Mass, Solubility
Difference btw Heterochromatin and Euchromatin - What is chromatin? What are the charges of each of the components - How are they wound - how does DNA interact with both Histones? Explain
Chromatin = DNA + Histones (eg Nucleosome) DNA = (-) P group Histones = (+) lysine & Arginine basic AAs - interact via dipole intermolecular bonds Heterochromatin = ↓ transcription - tightly bound together - bound by ionic interaction between (-) Phosphate on DNA and (+) lysine on histone Euchromatin = ↑ transcription - loosely bound together - modified by acetylation of K,R - added acetyl group neutralizes the (+) K, R on histone & reduces interaction between histone and DNA
Which leads to more membrane fluidity? cis or trans bond?
Cis bond b/c introduces bend or "kink" in FA that prevents phospholipids from stacking
Stereospecific reactions in the Citric Acid Cycle:
Citrate-->Isocitrate & Fumarate-->Malate
Diff btw coding (1) and non-coding (5) RNAs - functions
Coding RNA - mRNA - translated into protein by tRNA Non-coding RNA - rRNA - contains ribosomal proteins; enzymatically active - tRNA - pairs mRNA codon with its anticodon to form protein during translation - siRNA - Interfers with translation by binding mRNA and signal for it's degradation - miRNA - Interfers with translation by cleaving mRNA or prevent it from binding to ribosomes - snRNA - (protein + snRNPs) = sliceosome
Codominance
Codominance - describes the co-expression of alleles as observed in the phenotype of heterozygous individuals. In the case of codominant traits, neither allele is fully dominant or fully recessive. Common examples of codominance include the co-expression of both red (R) and white (W) alleles in a speckled offspring (RW). In this example, in vitro studies suggest that both wild-type and mutant TLRs are observable by protein electrophoresis. This phenotype can be attributed to the co-expression of the normally functioning receptor and the mutated receptor, or the codominance of tlr4(+) and tlr4(d) alleles.
Nuclear localization sequence
Composed of AA and functions as nuclear import tag, facilitates *TF* transport *into nuclear*
Extraction - Acid/base
Compounds with acidic or basic functional groups can enter the aqueous layer as ionic salts, which are formed by deprotonation or protonation by a base or acid of varying strengths Amine = Weak base - Need Strong Acid to form ionic salts for extraction Carboxylic acid = Strong Acid - Need weak base to form ionic salts for extraction Phenols = Weak Acid - Need Strong base to form ionic salts for extraction *Strong acid need weak base Strong base need weak acid*
route of urine from nephron to out - First to collect urine from CT - tube that connects the kidneys to bladder - where is urine stored? when does it exit the body? via? - what muscles control urination? (3) - which have smooth, striated, voluntary & involuntary muscles - what happens during urine collection - which relaxes/contracts and why? - what happens during urination - which relaxes/contracts and why? - Urinary retention is due to - Urinary incontinence is due to
Conc urine move from nephron → collecting ducts → renal calyces → renal pelvis → Ureter → Bladder →Urethra Urine is stored in bladder until filled, - then exits body via urethra (aka urination) Urination is under control of - the detrusor muscle (smooth muscle) - internal urethral sphincter (IUS - smooth) - external urethral sphincter (EUS - striated) During urine collection, - detrusor muscle is relaxed - while IUS + EUS are contracted --> to prevent urine flow down the urethra. During urination, - detrusor muscles contract - while IUS + EUS relaxes, - to push urine out of the bladder to urethra - detrusor + IUS are under involuntary control; - EUS is under voluntary control. - Urinary retention is due to nerve damage impairing detrusor muscle of the bladder - Urinary incontinence is due to nerve damage impairing EUS of the bladder
dilution factor (DF)
Concentrated stock → dilutions In a simple dilution, the concentration of a stock solution is reduced by dissolving a small volume into a larger volume of solvent. A dilution factor (DF) is the magnitude by which the stock solution concentration is reduced. The dilution factor = volume of solute transferred (VT) / final volume of the solution (VF)
What feature of dansylalanine allows for monitoring protein unfolding?
Conjugated pi bonds Educational objective: A conjugated system of alternating single and double bonds in a molecule causes electron delocalization. This delocalization allows the molecule to absorb a photon in the ultraviolet or visible region, exciting an electron to a higher energy state.
Peripheral Nervous System
Consists of all nerves and neurons located outside of the brain and spinal cord. Contains 2 branches: Somatic: transmits impulses from the central nervous system to the skeletal muscles, allow for conscious control. Autonomic: mediates subconscious, automatic functions that are not subject to voluntary control
Slow-twitch oxidative fibers
Contract at *SLOW* rate, less frequency of myosin heads hydrolyze ATP- aerobic respiration
https://www.khanacademy.org/test-prep/mcat/organ-systems/neural-synapses/v/neurotransmitter-release
Contraction of skeletal muscles is stimulated by transmission of a nerve impulse at the neuromuscular junction, -->the synapse between a skeletal muscle and a motor neuron. When an AP reaches the terminal of a motor neuron, - an influx of calcium through voltage-gated calcium channels triggers the release of ACh-containing vesicles (exocytosis) into the synaptic cleft. - Released ACh binds to receptors of the motor end plates, depolarizing the innervated muscle fibers and causing muscle contraction.
Diff btw Convergent, Divergent and Parallel evolution
Convergent - Different common ancestor - Diff env; similar unique characteristics - Analogous structures -eg- wings on insect, birds, bat Divergent - Same common ancestor - Diff env; Diff characteristics over time - Homologous structures -eg- forelimbs of vertebrates Parallel evolution - Same common ancestor - Similar env; similar unique characteristics
- *Functions of Cortisol - Functions of Aldosterone - what do they control?*
Cortisol - controls metabolism = ↑ gluconeogenesis = ↓ uptake of glucose by cells = ↑ protein catabolism(proteolysis)/↓ synthesis = ↑ triacylglycerol breakdown (release of FA) Aldosterone - controls electrolyte balance = by stimulating Na⁺ reabsorption and = excretion of K⁺ in the kidney → leads to water reabsorption in the kidney
Transcription
Creation of RNA from DNA sequence First step in gene expression Carried out by RNA polymerase which takes a ssDNA and synthesizes and RNA strands in the 5' to 3' direction Initiation: RNA pol binds to a sequence of DNA called promoter Elongation: template strand is copied by RNA pol one base at a time and converted into complement RNA strand. RNA base added to the 3' end of newly synthesized RNA strand Termination: RNA pol reaches terminator sequence, once those terminator sequences are transcribed, transcription is terminated
Transmembrane proteins
Cross phospholipid bilayer; inside= hydrophobic FA (inside=hydrophobic AAA residues on surface)
Prophase - Unique for? *How does it form? describe* - Diff btw mitosis and meiosis in prophase - *result of daughter cells?*
Crossing over events = Genetic Recombination →Tetrad (4 chromatids) - HomoC line up side by side to form tetrad - Allow physical contact btw paternal and maternal chromosomes at chiasma RESULT - Daughter cell with chromosome containing combination of allele that *differ* from parents mitosis = HomoC DO NOT pair up into tetrads meiosis = √Crossing over + Tetrad formation
What can increase genetic diversity?
Crossover events
Diff btw Crossover and alternative splicing Crossover events = leads to genetic diversity Alternative splicing = leads to protein diversity
Crossover events result in daughter cells with chromosomes containing combinations of alleles that differ from those in the parent cell, leading to eukaryotic genetic recombination and increased genetic diversity. Because crossover events produce genetically unique gametes, the offspring that develops after fertilization is genetically different from either parent and more genetically diverse. In alternative splicing, a single gene transcript is processed to produce various mRNA molecules that encode different proteins, depending on the inclusion or exclusion of particular exons. Alternative splicing can increase protein diversity, but it does not increase genetic diversity as the genetic makeup of an offspring is not altered.
Diastereomers → Enantiomers
Diastereomers = achiral = superimposable, non- mirror images *Diastereomers have different physical properties*. - can be separated from each other because, unlike enantiomers, they have different physical properties. Once the diastereomers are separated, the resolving agent is removed, yielding the original molecules as single enantiomers.
where are digestive proteolytic enzymes synthesized and secreted? - function
Digestive proteolytic enzymes - are synthesized and secreted from digestive organs(pancreas, stomach, and small intestine) - hydrolyze (breakdown) polypeptides,
Euchromatin:
DNA loosely associated with histones and is more easily transcribes
DNA polymerase, RNA Polymerase II & Ribosomes - what do they synthesize? - In what direction do they read/synthesize Which degrades quickly? *WHY* - RNA produced from DNA or DNA produced from RNA
DNA polymerase - synthesizes new DNA strands; - reads DNA template in 3' to 5' direction and replicate new strand in 5' to 3' direction RNA Polymerase II - synthesize pre-mRNA - reads DNA anti-sense strand in a 3′ to 5′ direction to transcribe a 5′ to 3′ pre-mRNA Ribosome - synthesize proteins - reads the mRNA transcript in a 5′ to 3′ direction until a stop codon (UAA, UAG, or UGA) is recognized, causing translation termination and polypeptide release. - RNA produced from DNA degrades quickly. - RNA is very unstable on its own, and will only last a short amount of time in the cell.
DNA polymerase
DNA polymerase - is involved in replication, not transcription.
SDS PAGE under nonreducing conditions
DNA samples are analyzed in nonreducing conditions as DNA has no disulfide bonds.
DNA sequencing
DNA sequencing - is a molecular technique used to determine the nucleotide order of DNA molecules. By analyzing the nucleotide sequences, DNA sequencing of whole genomes may be used to precisely quantify the copies of the gene present within a given tissue
Coding (sense) strand
DNA strand that complements noncoding DNA strand; has the *same sequence and directionality* as new mRNA transcrip (just witch U to T)
Reduced ventricular filling would lead to LESS blood being expelled from the ventricle with each contraction and ______ CO.
Decreased
Increase Ventricular filling -> Increased Stroke volume -> Increase cardiac input -> _____ Vascular Resistance
Decreased *Same for reversed
Journey of blood from type of blood entering the heart to going to tissues - Right side of lungs - Left side of lungs - Receiving chambers - Pumping chambers - Atrioventricular Valve (AV) - Semilunar Valve (SV)
Deoxy blood from tissues → (Post+Inf)Vena cava →R(atrium) →Tricuspid →R(ventricle) →Pul (artery)→capillary beds of alveoli in Lungs →gas exchange →oxy blood to Pul(vein) →L(atrium) →Bicuspid →L(ventricle) →Aorta → Tissues Right side of lungs = Pumps blood to lungs Left side of lungs = Pumps blood to tissues Right + Left atrium = Receiving chambers Right + Left ventricle = Pumping chambers - Atrioventricular Valve (AV) - Prevents backward flow to atrium - Semilunar Valve (SV) - Prevents backward flow to ventricles
Distillation
Distillation - is used to separate liquid molecules based on their boiling points. The compound with the lowest boiling point evaporates first. - The mixture is heated slowly so that the boiling temperatures of compounds with higher boiling points are not reached before the compound with a lower boiling point (distillate) evaporates and is collected. The three main types of distillation are - simple (bp of compds are25°C - 150°C apart) - fractional (bp of compounds are<25°C apart) - vacuum (bp of compounds are >150°C).
Reducing conditions show?
Disulfide bonds, would not show up in DNA, only protein
Purification yield
Dividing total activity of purified protein by total activity of unpurified extract
Who can pass through?
Due to their charged nature, ions cannot freely cross the plasma membrane because the membrane contains a middle layer of uncharged fatty acid chains. Consequently, an ion must pass through the pore of an ion channel to enter the cell. Ion channels are transmembrane protein complexes that fluctuate between an open or closed conformation to facilitate ion transport. These channels exhibit selectivity as only specific ions may pass through the pore and down their concentration gradient (high to low). For a particular ion to go through a channel, the inside of the channel's pore must be lined by amino acid residues with charges opposite to the ion's charge. This is because oppositely charged species attract each other whereas identically charged species repel each other. In addition, the ion must be briefly pulled out of its hydration shell to pass from the aqueous environment outside the plasma membrane to the aqueous environment inside the cell. The opposite charges within the pore stabilize the charge of the newly dehydrated ion. Per the passage, PC2 forms a mechanically activated Ca2+ channel. For positively charged Ca2+ to pass, the inside of the pore must be lined by amino acid residues that are negatively charged at physiological pH. Aspartate (D) and glutamate (E) are the only amino acids that fit this criterion. Arginine (R) and lysine (K) are both positively charged and would therefore repel positively charged Ca2+.
TLC and Rf
During (TLC), - The mobile phase (organic solvent) travels, a thin absorbent *silica plate* via capillary action - components travel up based on their polarity In normal phase TLC, - non-polar compounds (A) have less affinity for the polar stationary phase and therefore travel farther up the plate. - polar compounds (B) have a higher affinity for the polar stationary phase and therefore have a higher retention down the plate. Rf(A) = 6 cm/9 cm = 2 cm/3 cm = 0.67 Rf(B) = 3 cm/9 cm = 1 cm/3 cm = 0.33 An Rf value is always less than 1, and a smaller Rf value corresponds to a more polar, less mobile compound. ∴ Spot B is the more polar compound.
- what connects the 2 sister chromatids during prophase? - when does mitotic spindles fibers begin to form? - what is centromere composed of? - If bacteria is exposed to a spindle fiber toxin what happens? - main cause of disjunction?
During Prophase - 2 sister chromatids are connected by *kinetochore* to form a single homologous chromosome During Anaphase The mitotic spindle begins to form when centromere starts migrating to opposite poles of the cell & microtubule filaments grow from them → resulting in spindle fibers Centromere - composed of microtubule organizing centers with a pair of centrioles If bacteria is exposed to a spindle fiber toxin - It might inhibit microtubule polymerization and result in non-disjunction of somatic cells during nuclear division
Reverse transcription polymerase chain reaction (RT-PCR)
During reverse transcription polymerase chain reaction (RT-PCR), - the enzyme reverse transcriptase converts mRNA into double-stranded cDNA, which is then amplified in cycles to yield thousands of copies. The cDNA is initially denatured into single strands using heat, and forward primers and reverse primers anneal to the denatured cDNA strands so that polymerase can elongate the DNA sequence.
cell cycle: G2
During the gap between DNA synthesis and mitosis, the cell will continue to grow and produce new proteins. At the end of this gap is another control checkpoint (G2 Checkpoint) to determine if the cell can now proceed to enter M (mitosis) and divide.
Chromatin compaction
Educational objective: Chromatin compaction can influence accessibility of regulatory factors to DNA. The known H1 function is to stabilize chromatin compaction by securing nucleosome packaging. However, competing proteins would have the opposite effect, which would be to destabilize chromatin compactness and enhance accessibility to DNA.
Convergent, Divergent and Parallel evolution
Educational objective: Convergent evolution - leads to similar characteristics in distantly related species that are exposed to similar environmental pressures. Parallel evolution - occurs when two more closely related species (ie, descended from a more recent common ancestor) continue to evolve the same characteristics to adapt to similar environments. Divergent evolution - occurs when two species descended from a recent common ancestor inhabit contrasting environments and evolve distinct characteristics that allow them to better adapt to their differing environmental pressures.
DNA sequencing and Southern blotting
Educational objective: DNA sequencing and Southern blotting are DNA assays that may be used to assess the relative quantity of genes between tissue types. Northern blotting is an RNA assay used to assess gene expression in different tissues.
Genetic linkage
Educational objective: Genetic linkage refers to the tendency of alleles in close proximity to remain on the same chromosome and be inherited together by offspring. This tendency occurs because of fewer crossover events between these loci during meiosis, resulting in a greater number of haploid gametes with nonrecombinant genotypes.
cDNA cloning
Educational objective: In cDNA cloning, 1) reverse transcriptase generates a single strand of cDNA from a target mRNA sequence. 2) DNA polymerase synthesizes the second complementary DNA strand and amplifies the target cDNA sequence. 3) The target cDNA can then be inserted into a plasmid vector via the actions of a restriction enzyme (cuts both plasmid and vector) 5)The foreign cDNA and vector are cut by a restriction enzyme generating complementary sticky ends that anneal when both molecules are mixed together. 4) DNA ligase (joins the cDNA to the vector). *Therefore, Reverse transcriptase, DNA polymerase and restriction enzymes are required in cDNA cloning*
crossing over aka genetic recombination
Educational objective: In eukaryotes, genetic recombination occurs via crossover events (exchange of DNA segments between homologous chromosomes). Synapsis or the joining of homologous chromosomes into tetrads occurs during prophase I of meiosis and is required for crossing over to occur. Crossovers increase genetic diversity by mixing maternal and paternal alleles into a single chromosome that is then inherited by the offspring.
Ion channels
Educational objective: Ion channels allow charged atoms to pass between the extracellular and intracellular environments down their concentration gradient. The charge of the amino acids that line the inside of the channel's pore plays a key role in determining which ion can pass through.
Western Blot = Protein immunoblotting
Educational objective: Western blot (protein immunoblotting) - uses antibodies to detect specific proteins. Greater quantities of the protein of interest will manifest as larger bands on the resultant blot. In general, proteins with the shortest amino acid sequences have lower molecular weights and migrate quickly through the gel. Band intensity (thickness) demonstrates the relative levels of expression of the target proteins. Shortest AA sequence = Bottom Highest Concentration/Highest MW = Top
Telomeres
End of chromosomes that are repeatedly truncuated with each cell division round
What gland secrete hormones *What are Tropic hormones - eg- What are Non-Tropic hormones - eg- Hormones secreted by hypothalamus*
Endocrine gland = secrete hormones Tropic hormones (FLAT) - Hormones that regulate the secretion of other hormones by acting on the other hormone's endocrine gland -eg- LH (GnRH), FSH (GnRH), TSH (TRH), ACTH (CRH) - (ant. puit) Direct/Non-Tropic Hormones (PEG OVA) - act directly on non- endocrine tissues -eg- GH, prolactin, endorphins (ant puit) -eg- VasopressinADH, oxytocin (post puit) VasopressinADH, somatosatin, *dopamine*
RT-PCR
Enzyme *reverse transcriptase* converts *mRNA into cDNA* (double-stranded), amplified in cycles to yield thousands of copies
Structure of long bone includes what 3 parts?
Epiphyses, diaphysis, and metaphysis
Uniqueness of RBCs - function - organelles? - are they affected by mit mutations? - do they consume O₂ they transport? - How do they produce energy?
Erythrocytes (RBC) - DO NOT HAVE MIT. - contain (Hgb) - transport O₂ as they expel their nucleus & other organelles during erythropoiesis in bone marrow ∴ Mit mutations cannot affect RBC function - Never consume O₂ they transport - Produce energy via *anaerobic glycolysis*
RBC and WBC
Erythropoietin production: The adult kidneys normally produce erythropoietin, a hormone that signals the bone marrow to increase red blood cell (erythrocyte) production. Generation of erythropoietin would be impaired in ESRD Leukocytes production (white blood cells) occurs in the bone marrow, not the kidneys. Leukocytes are immune system cells that protect the body against infectious agents and foreign antigens. Consequently, leukocyte numbers are regulated by the presence or absence of cytokines released during active infection. Educational objective: The kidneys' primary function is to maintain the salt and water balance of the blood. They also play a key role in regulating multiple aspects of physiological homeostasis (eg, blood pressure, waste removal, osmolarity, blood pH, erythrocyte production).
Sex hormones secreted by ovaries - When does this secretion first happen - What happens during this stage
Estrogen Progesterone - Puberty (10-14yrs) - female sex organs grow & mature - sex traits develop (breast, widening of pelvis) - menstrual cycle starts
Diff btw Expressivity, Variable expressivity & Penetrance (complete & incomplete)
Expressivity - to what degree a penetrant gene is expressed Variable expressivity = range - 1 genotype → 2+ phenotypes expressed - single genotype give rise to a range of multiple phenotypes - eg- Hearing loss → mild ↔ severe Penetrance = proportion - 1 genotype → % of phenotypes expressed - Proportion of individuals with a genotypes who express the corresponding phenotype Complete Penetrance = genotype - 100% expressed in phenotype -Those with specific genoype *ALL* have ass. phenotype - eg- if you have the genes for being smart, then you'll definitely be smart Incomplete Penetrance genotype - <100% expressed in phenotype - Those with specific genotype but *SOME* express ass. phenotype - eg- you may have the genes for being smart, but you may not actually be smart.
What is Oogenesis - Female gamete; _____ is produced where - what kind of cell division is involved Order of Oogenesis - When does it begin? - what makes oogonium diff from germ cells (sperm & eggs) - What happens at each stage After fertilization → ________ is formed = _______ cell - _______ undergoes cleavage to ________
Female gametogenesis - Female gametes (oocyte) are produced --> in the ovaries - involves mitosis & meiosis Oogonium →1⁰ oocyte →2⁰ oocyte + first polar body →ootid Begins in utero at 4 wks gestation in female embryo 1) Oogonium - are diploid cells & first multiply quickly via mitosis 2a) 1° oocytes - begin meiosis but becomes arrested/stalled/functionally inactive in tetrad config (for later recombination) at Prophase I UNTIL PUBERTY ..... 2b) ovulation/menstrual cycles begin → stimulation of LH & FSH → causes 1° oocytes to resume meiosis I → till they get to Telophase I where they are divided (unevenly) 3) 2° oocytes - One of the daughter cells from telophase I begins (meiosis II) and halts in (metaphase II) - first polar body (the other daughter cell) - degenerates 4) Ootid - (second polar body) - 2° oocytes completes meiosis II to this After fertilization → Zygote is formed = diploid - Zygote undergoes cleavage to blastocyst
Inbreeding → ↓heterozygosity → ↓reproductive success, and ultimately → extinction or the elimination of the species.
Fitness is reduced in inbreeding populations because - inbred offspring have an increased probability of being homozygous for deleterious recessive traits due to the low genetic diversity between their parents. Individuals with low genetic diversity in MHC alleles have low fitness because it reduces their ability to fight novel diseases and pathogens. Therefore, repeated generational inbreeding within the cheetah population will lead to decreased heterozygosity, reduced reproductive success, and ultimately extinction or the elimination of the species.
Angiotensin 1
Floats through blood vessels - Endothelial cells on blood vessels convert angiotensin 1 to angiotensin 2
Genetic Drift
Fluctuation of allelic frequency due to chance events. Can lead to random loss of alleles w/in a pop. Low frequency alleles tend to have an increased probability of elimination in compared to high frequency alleles
When hydrostatic pressure > osmotic pressure, what happens?
Fluid accumulates in lungs
What feature of dansylalanine *(fluorescence)* allows for monitoring protein unfolding? - Fluorescence and conjugation
Fluorescence compounds can be used to monitor protein structure Fluorescence occurs when a photon in the ultraviolet (UV) or visible region is absorbed by a fluorophore. Photons in this region have enough energy to excite certain electrons to higher energy states. After excitation, the electron loses some of its energy as heat. - The remaining energy is emitted as a photon with a longer wavelength (less energy) than the one that was absorbed. *For a molecule to absorb UV or visible light, its electrons must be sufficiently delocalized* - so that the energy difference between the ground and excited states corresponds to the energy of the light being absorbed. *This delocalization can be achieved by a highly conjugated system*, or a system with several alternating single and double bonds. - In general, a larger system corresponds to a higher wavelength absorbed. The π electrons can be delocalized through the p-orbitals, creating an extended network of conjugated pi bonds known as resonance stabilization. *conjugation compounds allow fluorescence, and therefore monitoring of protein unfolding, to occur.*
Induction of Ca2+ release for skeletal muscle contractions
Following the release of acetylcholine by the motor neuron: ACh binds and opens the ligand-gated ion channels in the sarcolemma. Na+ flows down its electromagnetic gradient and into the cell through the channel, depolarizing the sarcolemma and resulting in an action potential. At certain location along the muscle fiber, the sarcolemma burrows deep into the cells forming channels: T-tubules, which bring depolarizing current close to the sarcoplasmic reticulum. The propagation of the action potential, leads to the opening of the Ca2+ channels in the SR, releasing Ca2+ and starting a muscle contraciton
For Proks - Archeae + Bacteria - size ≈ 1-5µm - One Origin of Replication - genetic information in circular chromosome - NO telomeres - NO histones - NO Introns - lacks membrane-bound organelles - NO Nucleus - Haploid DNA is in cytoplasm - tranS and transL occur simultaneously in the cytoplasm - Ribosome = 50S + 30S = 70S - *ETC is located on the plasma membrane.* - *under anaerobic conditions, ATP synthase is active* - *Fermentation yields alcohol in bacteria* - cells division via binary fission, - *Sexual reproduction is via conjugation*
For Euks - Plants, Fungi, Animals - size ≈ 10-30µm - Multiple Origins of Replications - genetic information in linear chromosomes - Have telomere-prevent DNA from unraveling - Have DNA + histone = Chromatin - Have Introns - Have membrane-bound organelles - Have nucleus - Diploid DNA is in nucleus - TranS & Post TranS Mod in nucleus; TranL in cytoplasm. - Ribosome = 60S + 40S = 80S - ETC is located in the Inner Mit Membrane - under anaerobic conditions, ATP synthase is not active - Fermentation yields lactic acid in the muscles of Euks - Cell division is via meiosis (germ cells) and mitosis (somatic cells) - Sexual reproduction is via fusion of gametes (meiosis)
Fractional distillation
Fractional distillation - works best for compounds that have boiling points that are <25°C apart, - eg chloroform and benzene (19°C diff in b.pt) fractionating column is added; - To *provide a larger surface area* on which the vapors of the distillate condense before distilling into the receiving flask. - Increased surface area allows for better separation of compounds with similar b. pts ↑Surface Area = Better separation
Cell Cycle
G0: Cells are functional but in a non growing state, cell cycle is arrested G1: Cells prepare for division by generating organelles necessary for energy & protein production G1/S checkpoint: Cell decides to commit to cellular division based on internal readiness(size, energy status & integrity of unreplicated DNA) & external factors S: DNA replication(synthesis) occurs G2: Cells synthesize proteins to ensure that sufficient organelles & cytoplasm are available for division into 2 daughter cells G2/M checkpoint: DNA is checked for error & corrections are made when possible(apoptosis results if correction attempts fail) M: nuclear & cellular division occurs during this stage via mitosis & subsequent cytokinesis(cytoplasm & organelles divide to generate 2 daughter cells)
Heterochromatin & Euchromatin
Gene transcription from DNA to RNA depends partly on the chromatin structure of the DNA that contains the gene. 2 forms of Chromatins - heterochromatin and euchromatin. Heterochromatin - consists of DNA that is tightly coiled around histone proteins, bound by an ionic interaction between the negatively charged phosphates on the DNA backbone and positively charged lysine residues in the histone. - DNA in heterochromatin is not readily accessible to RNA polymerase and so cannot be readily transcribed. Euchromatin - forms when histones are modified, often by acetylation of lysine residues. The added acetyl group neutralizes the positive charge on the histone, reducing interactions between histones and DNA. The reduced interactions yield a more open form that is more accessible to RNA polymerase, allowing euchromatin to be more readily transcribed. - Relatively open, uncoiled DNA is characteristic of euchromatin Because somatic cells transcribe TERT at low levels, the gene that encodes TERT is most likely found in *heterochromatin* within these cells. In somatic cells, the TERT gene is therefore most likely in a portion of the chromosome that is tightly wound around histones.
Genetic Linkage During recombination, what happens when; - 2 genes are located close to each other - 2 genes are located far from each other - composition of recombinants to parental in new homoC
Genetic Linkage = ↑parental/non-recombinant - Tendency of allele in close proximity to remain on same chromosome & be inherited together by offspring 2 genes located close to each other - tend to hang on to each other and transfer together rather than combine with others - ∴ New HomoC = ↓recombinants, ↑parental 2 genes located far from each other - tend to be free to combine with others - ∴ New HomoC = ↑recombinants, ↓parental
- Genetic Recombination - Recombinants - Parental
Genetic Recombination = Crossing over events Recombinants - Only the new combinations of alleles - from mom and dad and vice versa Parental - Original combinations that already existed in the parent
Genetic drift = chance event
Genetic drift - due to random genetic changes that are not related to natural selection - (eg, sampling error, chance event). - Although all populations are affected by genetic drift, its effects are more significant in --> smaller populations because they have a reduced gene pool. The smaller gene pool cannot buffer random (good or bad) variations in allele frequencies that occur due to chance events. In other words, the probability of a beneficial allele being removed by genetic drift increases for populations whose genetic diversity is low. Similarly, drift increases the probability of a deleterious allele becoming fixed within the population.
G protein-regulated cAMP signaling pathway
Glucagon acts on target cells by - binding its G protein-coupled receptor on the cell membrane and inducing the adenylyl cyclase/cAMP second messenger cascade. - The G protein "attached" to the transmembrane cell surface receptor is composed of three subunits: alpha, beta, and gamma. When the α subunit of a G-protein (Ga)is bound to GDP, the protein is inactive. - when ligand binds to G-protein receptor, GDP is replaced with GTP - The GTP-bound Ga dissociates from the β & γ subunits and proceeds to activate adenylate cyclase, an enzyme that catalyzes the conversion of ATP to cAMP, a second messenger. - cAMP then activates protein kinase A, which subsequently phosphorylates the proteins necessary to produce ligand-specific physiological effects - (eg, in the case of glucagon: induction of glycogenolysis and gluconeogenesis). - (eg, in the case of PTH; calcium is released)
→ Pancreas Hormones (insulin/glucagon)
Glucose is a key energy source for many tissues in the human body. The serum level of glucose is tightly regulated through the actions of the hormones insulin, glucagon, epinephrine, norepinephrine, and the glucocorticoids.
Glyceraldehyde
Glyceraldehyde - is an oxidized form of glycerol. - It is a three-carbon aldose with - 1 aldehyde group (H-C=O) - 2 hydroxyl groups (OH) - has stereocenters D- and L-
Glycerol
Glycerol - contains 3 hydroxyl groups (one on each carbon). - has no stereocenters and is neither D nor L. One of the terminal hydroxyl groups would need to be oxidized to an aldehyde to form glyceraldehyde.
Cell cyecle - phases & function - which is done outside the cell cycle? - what are Restriction Point/Checkpoints - what are the regulated by - what happens to abnormal cells - what happens if it doesn't work - what happens during each check point? - what phase are majority of cancer cells G₀ or interphase & why - what kind of drug do you use to inhibit cell division?
G₀(outside cell cycle)→G1→S→G2→M G1 = Cell growth/Replication S = DNA synthesis/replication G2 = Cell growth/Check for errors in prep for cell division M = Mitosis (Nuclear division) + Cytokinesis (Cytoplasm division) Restriction Point/Checkpoints - Mechanism by which calls regulate their content within the cell cycle - Regulated by → cyclins & cyclin-dependent kinases - some abnormal cells undergo apoptosis, others that can't be repaired continue to divide G1/S Phase transition - cells commit to undergo a division cycle G2/M Phase transition - acts as quality control by stopping cell cycle & checking for abnormalities Cancer cells - uncontrolled cell division/ ↓apotosis - means majority of cells are in interphase & not arrested in G₀ (dormant phase) To inhibit cell division - use drugs that target actively dividing cells in the G1-M phase
How to identify pure substances
HPLC chromatogram - A pure reaction product would show only one absorbance peak indicating only the presence of a compound on the HPLC chromatogram. 1H NMR spectrum - There are three unique methyl (−CH3) groups in caffeine; therefore, a pure caffeine product would show three unique −CH3 signals in its 1H NMR spectrum. TLC - If a single spot with a larger Rf than that of the reactant is visible on the product sample track on the TLC plate, then the isolated product is pure - a single spot on a TLC plate is indicative of a compound's purity. SC - cannot be used to purify a compund because it separates compounds by size; therefore, compounds that are similar in size elute together. An absorbance peak indicates only the presence of a compound, not the number of compounds contributing to the absorbance.
native PAGE gel
Has no denaturants or reducing agents; allows DNA to traverse gel in native state
Fallopian cilia
Helps propel fertilized oocyte toward uterus for implantation; deficiency in this could cause implantation of egg *outside uterus*
Hematopoietic stem cells - where do they originate - what do they differentiate into ....
Hematopoietic stem cells - originate in bone marrow & differentiate into myeloid and lymphoid Lymphoid progenitor cells - go on to become B cell, T cells and NK cells Myeloid progenitor cells - go on to become RBCs, monocytes, neutrophils, basophils, eosinophils, megakaryocytes & mast cells
Both telomeres and centromeres are made of ___
Heterochromatin
High-performance liquid chromatography (HPLC)
High-Performance Liquid Chromatography (HPLC) separates compounds based on polarity - a mobile phase = liquid - stationary phase = polar/non-polar column - detector, and - computer for data acquisition. HPLC is optimal for small sample sizes and separates compounds based on their polarity, - causing the compounds to pass through the column at different rates. Compounds are detected as they come off the column and go into the waste or are collected separately. Data is transmitted to the computer, creating a chromatograph.
SDS procecudre
Highly crosslinked polyacrylamide gel coats proteins with negative charge -> current -> smaller proteins travel faster
Function of endocrine system: specific chemical control at cell, tissue, and organ level
Hormones affect the function of diverse and distant tissues in the body. This is because hormone receptors can be expressed in a variety of cell types located throughout the body, and any cell that expresses the correct receptor is capable of responding to the receptor's ligand (hormone). For example, glucocorticoids released into the bloodstream from the adrenal cortex influence the energy metabolism of skeletal muscle cells, liver cells, and fat cells, which all express glucocorticoid receptors. However, in glucocorticoid deficiency, an insufficient amount of glucocorticoid hormones in the blood leads to diminished binding of these hormones to their receptors. This condition would compromise the normal function of the various cells that express glucocorticoid receptors.
During asthma attack, bronchoconstriction has what effect on blood pH & homeostatic response is?
Respiratory ACIDosis and increased respiratory rate
Endocrine System: Hormones and Their Sources (BIO)
Hormones are chemical messengers that influence physiologic function through endocrine signaling, a form of long-distance cell-to-cell communication. In endocrine signaling, hormones are secreted into the bloodstream by specialized cells and transported throughout the body via the circulatory system. Once the hormone reaches its target tissue, it alters cellular function in one of the following ways: 1) Water-soluble (hydrophilic) hormones generally bind a cell surface receptor and initiate a second messenger cascade, leading to changes in protein activity (eg, enzymes, membrane channels). 2) Water-insoluble (hydrophobic) hormones generally diffuse across the lipid bilayer of the plasma membrane and bind to a cytosolic receptor to ultimately regulate gene expression in the nucleus.
- *What is endrocrine signaling? - How are hormones transported throughout body? - How do water soluble & water insoluble hormones alter function once they get to the target tissue?*
Hormones function through - endocrine signaling (a form of long distance cell-to-cell communication) Hormones are transported through - circulatory system (blood stream) Once it gets to it's target tissue, how does it alter cell function? 1) Water soluble (hydrophilic) hormones - Travel freely through the bloodstream & act as first messengers by binding to (extracellular) cell surface receptors on target cell membrane → to initiate an (intracellular) second messenger cascade → leading to change in protein activity 2) Water insoluble (hydrophobic) hormones - - Either bind to a carrier protein in the bloodstream & act as first messengers OR dissociate from carrier protein & diffuse across the lipid bilayer of plasma membrane to bind to a cytosolic receptor → to regulate gene expression in nucleus.
What are BP regulators (hormones)? - what does a decrease in the hormones imply?
Hormones such as - angiotensin II, - aldosterone, and - antidiuretic hormone (ADH; vasopressin) Regulate BP by ↑kidney's reabsorption of water and salts. - causing BP to increase. ↓in any of these hormones = ↓BP
Blood pressure regulators
Hormones such as - angiotensin II, - aldosterone, and - antidiuretic hormone (ADH; vasopressin) Regulate BP by modulating the kidney's reabsorption of water and salts. - causing blood pressure to increase. Accordingly, a decrease in any of these hormones would cause BP to fall.
multiply the original number of bacterial cells by 2^n (n = number of generations)
How do you find the number of cells that result when a single cell divides by binary fission?
by histone modification via acetylation of lysine residues, reducing the interactions between histones and DNA
How does euchromatin form?
Which of the following helps maintain the resting membrane potential of a neuron? I. Passive transport II. Adenosine triphosphate III. Membrane selective permeability
I, II, III: -unequal concentration of charged ions btw the extracellular and intracellular fluid of all living cells results in an electrochemical gradient across membrane that determines the membrane potential (voltage difference). *The resting membrane potential of neurons due to high K+ and low Na+ inside the cell -protein channel presence in the cell membrane allows passive transport of certain ions down their electrochemical gradient. -Active transport pumps help maintain the concentration gradient and are critical for maintaining the resting membrane potential. -selective membrane permeability is responsible for generating the resting membrane potential in nerve and muscle cells.
If two genes are located close together on a chromosome = fewer progeny with recombinant combinations than parental combinations.
If two genes are located close together on a chromosome (measured in centimorgans, or map units), - they are relatively unlikely to be separated by a recombination event. This is because there is less distance between the two genes in which a recombination can occur. Therefore, substantially fewer progeny will have recombinant combinations than parental combinations. - As a result, the recombinant progeny can be identified by the fact that there are fewer of them. Table 1 shows that only 43 of 500 flies (~9%) were recombinant. Given this small percentage of recombinant flies, it is likely that the PTP and Abl genes are close together on the chromosome.
Shielded/upfield Deshieded/downfield
In general, the magnitude of shielding is dependent on the local chemical environment. Shielded - protons within or near methyl groups are surrounded (shielded) by a high electron density and have a smaller chemical shift (upfield). ---> More Hs Deshieded - Nearby electronegative atoms, such as oxygen and nitrogen, pull electron density away from (deshield) the proton. Therefore, an NMR peak corresponding to a carboxylic acid (-COOH) proton would have a higher chemical shift (downfield).---> Less Hs *The NMR peak at 1 ppm has a comparatively small chemical shift (upfield), which suggests that protons corresponding to this peak are more shielded by the surrounding electron density.* *shielded = upfield = small chemical shift deshielded = downfield = large chemical shift*
Incomplete dominance
Incomplete dominance - between alleles results in a blended or intermediate phenotype observed in heterozygous individuals. A common example is pink color (Rw) in offspring produced from a cross between red flowers (RR) and white flowers (ww). Similarly, quantitative data indicate that the heterozygous F1 generation [tlr4(+)/tlr4(d)] has an intermediate immune response to LPS when compared to He-N mice [tlr4(+)/tlr4(+)] and He-J mice [tlr4(d)/tlr4(d)] mice. This result could be attributed to incomplete dominance.
Infrared Spectrum
In infrared (IR) spectroscopy, - a sample is irradiated with IR light, and a spectrometer detects and records the percentage of radiation that passes through the sample over a range of frequencies. The IR spectrum of a compound indicates - the types of bonds and - functional groups present in a compound. Different functional groups absorb IR radiation at different frequencies, and therefore the signal from each group appears in a particular region of the IR spectrum. Although individual molecules may have distinct absorption spectra in the fingerprint region (700-1500 cm−1), each functional group on the molecule will still absorb in its characteristic IR region regardless of the global structural features of the molecule.
Diff btw Sex-linked & Autosomal traits - what creatures have these? - due to allele expressed in? - who is more affected? males/females
In mammals and some insects, genetic traits are passed to next generation in either; Sex Linked Traits - (XX or XY) - due to allele expressed in sex chromosomes - (X) contains more genes than (Y) - *Males are more affected → have only 1(X)* Autosomal Traits - (the other 23 pairs) - due to alleles expressed in autosomes - same # passed from parent to offspring - *both male and female are affected equally*
How does the body respond to stress?
In response to stress, - the hypothalamus stimulates the pituitary gland to release (ACTH). - As a result of ACTH release, the adrenal cortex secretes glucocorticoid hormones such as cortisol. - Cortisol mediates stress responses by increasing blood glucose levels and decreasing inflammation and protein synthesis. Chronic exposure to cortisol can negatively impact immunologic responses, increase the susceptibility for diseases, and affect reproductive health (fecundity).
stabilizing selection = average
In stabilizing selection, - phenotypes are narrowed toward an average, homogeneous phenotype by selecting against extreme phenotypes; - as a consequence, diversity is decreased within the population.
Describe gray and white matter position in brain & spinal cord Describe info carried from body to spinal cord, brain & vice versa
In the CNS - gray matter is composed of cell bodies - white matter is composed of axons Axons allow long-distance communication between neurons. Afferent axons carry sensory information from the body to the brain through tracts in the spinal white matter. Efferent axons carry motor commands from the brain to the body through tracts in the spinal white matter.
https://www.khanacademy.org/test-prep/mcat/organ-systems/biological-basis-of-behavior-the-nervous-system/v/gray-and-white-matter https://www.khanacademy.org/test-prep/mcat/organ-systems/biological-basis-of-behavior-the-nervous-system/v/autonomic-nervous-system https://www.khanacademy.org/test-prep/mcat/organ-systems/neural-cells/v/overview-of-neuron-function
In the CNS, - gray matter is composed of cell bodies - white matter is composed of axons Axons allow long-distance communication between neurons. In the white matter of the spinal cord, afferent axons carry sensory information to the brain and efferent axons carry motor commands to the body. Afferent (from skin) → White Matter (axon on spinal cord)
ITC experiment = (an in vitro technique) - performed outside of living organisms Western Blot = (an in vivo technique) - performed in living organisms
In the ITC experiment (an in vitro technique that uses purified proteins), - the dissociation constant Kd is used to determine the binding affinity of proteins. - The low Kd shows a higher binding affinity . In the in vivo experiment, (in which proteins were extracted directly from cells), - the results are the opposite. - the thicker band of the western blot indicates increased binding. Smallest Kd = Highest affinity Thickest band = Highest affinity
Anaphase I and II
In the absence of recombination, maternal and paternal alleles are separated from each other during anaphase I, and identical alleles on each sister chromatid are separated from each other - (pulled to opp poles by the mitotic spindle ) during anaphase II. Mitosis Ana-Sister chromatids separate (diploid Anaphase I - Homo Chromosomes separate Ana II-Sister chromatids separate (haploid)
proximal tubule
In this segment, important nutrients are absorbed from the nephron and incorporated back into the blood through peritubular capillaries that surround the tubule
Diff btw Inbreeding Depression & Random Mating - effect on zygosity, genetic diversity, fitness, fecundity, MHC on offsprings - Why is random mating better - How do you increase heterozygosity among inbreeders
Inbreeding Depression = Mating (relatives); - *↓Heterozygosity=↓genetic diversity=↓fitness* - homozygous for deleterious recessive traits - ↓fecundity (# of offsprings) - ↓MHC - ↓ability to combat infection Random Mating = Mating (non-relatives); outbreeds - *opposite of above* - *↑Heterozygosity*=↑genetic diversity=↑fitness* - ↓ probability of passing familial abnormalities to offspring Random mating better- due to introduction of new genetic material To increase heterozygosity among inbreeders - selectively outbreed with others
Respiratory acidosis
Incerased levels of circulating free h+ ions, due to increase in CO2 levels in blood
Processing of pre-mRNA
Includes splicing; pre-mRNA transcript into mature mRNA; occurs in necleus
*Diff btw Independent assortment & Recombination - How do each explain resemblance to parent and or child*
Independent assortment helps explain why the offspring may not resemble the parent Recombination helps explain why offsprings may not resemble each other → reason why a couple can have ten unique children.
What is cell fate influenced by?
Inductive signaling between cells in early embryo
Phases of Cell Division during cell cycle - Guess the ffg stages- correction of errors, duplication of organelles, duplication of DNA, quiescent, cytoplasmic division, nuclear division, separation
Interphase G₀ - quiescent (inactive/dormant) - cell is neither dividing nor preparing to divide - occurs outside of the cell cycle. G₁ - cell growth & duplication of organelles S - REPLICATION/DUPLICATION of DNA G₂ - cell growth, duplication & correction of errors in preparation for cell division M - Mitosis - Separation & Nuclear Division - Cytokinesis - Cytoplasmic Division
Topoisomerase
Introduces (-) supercoiling in DNA double helix ahead of replication fork to reduce strain produced by unwinding
Quaternary structure
Involves interactions b/w separate polypeptide chains, called subunits, to form multiprotein complex
Isomer → Stereoisomers → Cis/Trans →Separated by Gas Chromatography based on boiling points
Isomers - are molecules with the same molecular formula but different structural arrangements. They can be generally classified as constitutional isomers and stereoisomers. - Constitutional isomers differ in atom connectivity whereas - Stereoisomers have the same atom connectivity but differ in spatial arrangement. Stereoisomers that arise from disubstituted double bonds are called --> geometric isomers. - They are classified as cis or trans *Geometric isomers (cis/trans) can be separated by gas chromatography because they have slightly different boiling points.* *Both cis and trans isomers have (unsaturated) - the same molecular weight and - the same m/z ratio* *... but will come off the GC column at different times, yielding two distinct peaks.*
What is order in which precursors of steroid hormones are made?
Isoprene -> monoterpene -> squalene -> cholesterol
The juxtaglomerular (JG) cells
JG cells - special smooth muscle cells in kidney - release renin - eventually helps to raise BP
dissociation constant equation
Kd = [Ab][Ag] / [AbAg] where [Ab] is the conc. of unbound antibody, [Ag] is the conc of unbound antigen, and [AbAg] is the equilibrium conentration of antibody-antigen complexes
Loading controls = Housekeeping genes expressed ubiquitously
Loading controls - are used to normalize protein detection and ensure that protein loading and mobility are standardized across the gel. - Proteins used as loading controls tend to be ubiquitously expressed as they have consistent concentration levels across all cell/tissue types regardless of varied experimental conditions. The most common loading controls are proteins necessary for baseline cellular function that are transcribed from housekeeping genes (eg, α- and β-tubulin proteins are structural/mobile cytoskeleton components). Educational objective: Loading controls normalize protein detection and ensure that protein loading is standardized across the gel. Proteins used as loading controls tend to be ubiquitously expressed and have consistent concentrations across all cell/tissue types. Housekeeping genes are the most common loading controls.
FA structure & membrane fluidity
Long saturated chain= LOW fluidity Long unsaturated= increased fluidity (*double bonds*)
Mechanism of Gas-liquid chromatography (GC)
Low boiling points = Volatile molecules - spend more time in the gas phase rather than interacting with the liquid stationary phase of a GC column and travel quickly to the detector. Higher boiling points = Molecules - condense and spend more time interacting with the liquid stationary phase and slowly make their way through the column as the temperature increases.
How to increase the relative signal intensity of peaks that correspond to smaller mass-to-charge (m/z) values?
Lowering the pH of the solvent - increases the conc of protons & will result in a greater # of multiply charged molecules or the signal intensity of the smaller m/z values (z > 1). - An increase in multiply charged molecules would therefore result in greater signal intensity for smaller m/z values. Signal intensity of a mass spectrometry peak corresponds to the relative quantity of ions at a given mass-to-charge ratio m/z. Increased charge yields a decreased m/z ratio; - therefore, an increase in the number of multiply charged particles increases signal intensity at lower m/z ratios.
Lymph node & Spleen - what lives there - function
Lymph Node - WBCs live & proliferate here after maturation - *filters lymph* to remove pathogens - resident lymphocytes monitor lymph for foreigners & initiate an immune response if any Spleen (aka-blood node) - WBCs live & proliferate here after maturation - *filters blood* to remove pathogens - stores RBCs - removes old RBCs & platelets
lysosome vs lysozyme
Lysosomes contain several proteases, including a broad spectrum enzyme,elastase, which is important or even essential for killing various bacteria. Another anti-microbial protein is lysozyme, which attacks the cell walls of certain (gram positive) bacteria.
- Macula densa cells, location & functions? - what do they secrete? to where? - what are juxtaglomerular (JG) cells, location & functions? - what triggers the release of Renin (3)
Macula densa cells - are part of the DCT of Nephron - they gets a taste of the water and sense ↓Na+ and realize it's due to ↓filtration by the glomerulus (ie ↓BP) - They send prostaglandins to the JG cells - this triggers the release of Renin JG cells - special smooth muscle cells in kidney - release renin - eventually helps to raise BP 1) ↓B.P 2) Sympathetic Nerves cell firing 3) ↓Na⁺
Secondary structure
Mainly alpha-helices and beta-sheets, formed by *hydrophobic* bonds b/w *backbones* of AA
What are the 2 ways viruses enter the's host cell which method does Non-enveloped (Naked) Viruses & Enveloped Viruses use? - how do they do this? - which binds to receptor protein on cell surface - which forms vesicles? - what kind of drug will inhibit cell entry? - which fuses to host membrane - what is released into the cell with each method?
Many viruses enter host cells via; - receptor-mediated endocytosis (phagocyte) --> (Non-enveloped) OR - by fusing their membrane with the other cell membrane --> (Enveloped) Non-enveloped (Naked) Viruses - Enter cell via receptor-mediated endocytosis → bind specific receptor protein on cell surface → this induces the plasma membrane to bud inward towards the cytosol → then the formed vesicle is pinched off containing both ligand (with capsid) + receptor - A drug that inhibits this inward budding would likely prevent virus from entering cell Enveloped Viruses - Enter cell by fusing their membrane with the host cell membrane - Their capsid is enclosed in a phospholipid membrane & no vesicle is formed - Capsid is then released into the cytosol - A drug that inhibits fusion of viral & cell membrane needed would likely prevent virus from entering cell
Erythrocytes (RBC) contain no mitochondria - As a result, mitochondrial mutations do not affect erythrocytes.
Mature red blood cells (RBCs), or erythrocytes, - mainly contain hemoglobin, - RBCs are highly efficient transporters of oxygen as they expel their nucleus and other organelles during synthesis (erythropoiesis) in the bone marrow to maximize the available space for hemoglobin. As a result, RBCs contain *no mitochondria* and so, *mitochondrial mutations cannot affect erythrocyte function*. RBCs never consume the oxygen they are transporting as they produce energy only via anaerobic glycolysis, an oxygen-independent metabolic pathway that is less efficient than the aerobic one.
Norepinephrine and epinephrine - associated with sympahetic NS
Norepinephrine and epinephrine - are amino acid-derived hormones - released from the adrenal medulla as part of the fight-or-flight response. - Norepinephrine is also the major postganglionic neurotransmitter of the sympathetic nervous system.
Mechanical & Chemical digestion
Mechanical digestion = physically breaks down of food particles into smaller pieces .. eg - Emulsification by bile - chewing in the mouth and - churning in the stomach due to peristaltic Chemical digestion = cleavage of chemical bonds to simpler compds that can be absorbed - is carried out by acids and enzymes eg - Salivary amylase hydrolyzes polysaccharide starch into the disaccharide maltose. - Pancreatic Lipase hydrolyzes triglycerides within micelles into free FAs & monoglycerides - Lingual lipase
mitochondrial DNA - inherited in a maternal fashion (ie, no paternal contribution). Mitochondria within sperm are not transferred into the ovum during fertilization; therefore, males never pass on their mitochondria.
Mitochondria - have their own genome; (DNA) Their main functions include - ATP generation, - heat production, and - beta-oxidation of fatty acids. Mitochondrial genes are extranuclear and inherited in a distinctly different manner than nuclear genes (autosomal and sex-linked). During fertilization, mitochondria within sperm do not pass into the ovum; therefore, - - only maternal mitochondria are transmitted to the fetus. Only affected females transmit abnormal mitochondria to offspring; transmission never occurs through males, even if they are affected. - As a result, only affected mothers with the mtDNA A3243G mutation can pass it on to their offspring.
HPLC
Molecules with a polarity similar to the stationary phase have longer retention times than molecules with polarities similar to the mobile phase. In Normal Phase - (HPLC) - stationary phase is a polar compound and the mobile phase is a non-polar solvent ELUDE FIRST - Non-Polar (eg Hydrocarbons) ELUDE LAST - Polar (eg Water, Silica) - longer retention time
Higher salt concentration in DNA means?
More ionic strength= more resilient
Hyaline cartilage
Most common type of cartilage; it is found on the ends of long bones, ribs, and nose
Mouth → Duodenum (including sphincters) - what does sphincter do? - where are they located?
Mouth → Esophagus → Cardiac Sphincter → Stomach → Pyloric Sphincter → duodenum sphincter constricts = to keep content in sphincter relaxes = to allow the natural passage of substances based on physiological requirements Cardiac Sphincter = at the junction of the esophagus and stomach - controls the passage of food into the stomach and prevents backward flow Pyloric sphincter = at the junction of the stomach and the duodenum. - controls the flow of chyme from the stomach into the duodenum.
Muscle Contraction
Muscle fiber @ rest: myosin head is in high energy confirmation (upright and bound to ADP and Pi), actin is bound to tropomyosin and troponin, these act to block myosin binding sites Following depolarizing stimulus by motor neuron, Ca2+ is released from the sarcoplasmic reticulum into the cytosol. Ca2+ binds troponin, causing a conformational change that pulls on tropomyosin and exposes myosin binding sites. Myosin head then binds to actin filament via the myosin binding sites. ADP and Pi are then disassociated, causing the power stroke-->pivot of the myosin head dragging the actin filament toward to the center of the sarcomere. Myosin head is now in low-energy conformation and a new ATP molecule binds to it, disassembling the crossbridge b/t myosin head and actin filament. Hydrolysis of the ATP molecule allows for the myosin head to shift back into its upright and high energy conformation. This will continue until Ca2+ is sequestered back into the sarcoplasmic reticulum
Describe Cross-bridge dissociation
Myosin head released into low-energy position
do bacteria develop immune reactions to antibiotics?
NO bacteria may experience random mutations that confer resistance, but they will not actively develop immunity as a result of repeated antibiotic exposure
What antigens does blood type O have?
NONE *universal donor*
Diff & Simil btw Natural selection, gene flow, random mating - caused by? - effect on genetic diversity, fitness, *allele*, pop size, survival
Natural selection = Survival of the fittest Gene flow = due to Migration Random mating = Mating (non-relatives); outbreeds ALL - ↑ genetic diversity due to variation during meiosis (recombination/crossing over) - increase species fitness - introduces new alleles to gene pool - ↑probability of survival - ↑population
Cross of female carrier of *X-linked recessive trait* and unaffected man
ONLY male children express trait; 0.5 x 0.5= 25% offspring express trait
capillary osmotic pressure
Oncotic pressure, or colloid osmotic pressure, is a form of osmotic pressure exerted by proteins, notably albumin, in a blood vessel's plasma (blood/liquid) that usually tends to pull water into the circulatory system. It is the opposing force to hydrostatic pressure.
describe the role of progesterone in female fertility
One of progesterone's most important functions is its role in thickening the lining of the uterus each month. The enriched endometrial lining is prepared to receive and nourish a fertilized egg.
Order of Spermatogenesis - what kind of cell division is involved? - Function of each - more on spermatozoon
Order of Spermatogenesis = S/gonium → S/cyte → S/tid →zoon - involves mitosis & meiosis 1) Spermatogonium - divide by mitosis to yield 2 daughter cells 2) Spermatocyte - One of the daughter cells (in beginning of meiosis I) 3) Spermatids - The daughter cell matures to this (after meiosis II) 4) Spermatozoon - Mature cell loses most of it's cytoplasm, forms acrosome, mitochondria, tail/flagella and becomes this Spermatozoon - small, non-motile gamete that bear little resemblance to the original Spermatogonium
Protecting groups
Organic synthesis requires reactions at specific functional groups to make the target compound. - However, some molecules have multiple functional groups that could react under the given conditions. *Protecting groups are added to organic molecules to modify the functional group by masking it*. - Protecting groups prevent unwanted reactions under given reaction conditions - They tend to be stable to oxidation and reduction conditions and prevent nucleophilic reactions from occurring. There are particular protecting groups for each type of functional group. After a reaction is complete, the protecting group can then be removed to reveal the original functional group. The addition of dansyl chloride to Compound 1 requires an amine nucleophile to attack the electrophilic sulfur atom in dansyl chloride. - Because there are two amines in Compound 1, the one bonded to the α-carbon needs to be protected so it will not react and this allows the other amine to perform a nucleophillic attack The Boc group provides steric hindrance to prevent the amino group from acting as a nucleophile.
Organisms catabolize (breakdown) glucose via; (2) - what do they have in common? - what kind of condition do they occur? aerobic, anaerobic - where does glycolysis occur in Proks & Euks?
Organisms catabolize (breakdown) glucose via; 1) Cellular respiration = yields CO₂ and H₂O C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O 2) Fermentation = yields inorganic waste Pyruvate →Ethanol(Proks) OR Lactic acid(Euks) - Both begin with glycolysis - Glycolysis does not require O₂ ∴ both occur under aerobic & anaerobic conditions - 1Glucose is broken down → Pyruvate → in cytosol of both Euks and Proks
Female Reproductory organs Female gonads Female gametes Male Reproductory organs Male gonads Male gametes
Ovaries→Fallopian tube →Uterus→ Cervix →Vagina Female gonads = Ovaries Female gametes = OOcytes SEVEN UP Male gonads = Testes Male gametes = Sperm
The 60S subunit binds the initiator tRNA at the ____ site
P site -> marks formation of translation complex
P value > 0.05 and P value < 0.05
P value > 0.05 - means there is a > 5% probability that the result is by chance if null hypothesis is true - ∴ not statistically significant P value < 0.05 - means there is a < 5% probability that the result is by chance if null hypothesis is true - ∴ statistically significant
Passive Transport (Simple + Facilitated Diffusion) & Active Transport - *types of stuff allowed to pass through?* - eg
Passive Transport = *No energy needed* if moving down conc gradient (high to low) 1) Simple - *Small Molecules + lipid soluble* - *travel membrane directly*, don't need gates 2) Facilitated - *Large Molecule + charged* - *pass via protein channels or gates* Active Transport =*Need ATP to run pumps* moving against conc gradient (low to high)
Transporters
Passive transport - is the movement of a substance across a cell membrane along its concentration gradient (ie, high to low conc) and does not require energy. Active transport - is the movement of a substance across a cell membrane *against* its concentration gradient (ie, low to high conc) and does require energy. There are two types of active transport: Primary (direct) active transport - uses the energy released by ATP hydrolysis (performed by a transmembrane ATPase). to establish the conc gradient eg Na+/K+pase Secondary (indirect) active transport - is a coupled transport process that utilizes the energy released by the movement of one substance along its concentration gradient (passive transport) to move another substance against its concentration gradient. Essentially, the potential energy stored in the concentration gradient of one molecule is used for the transport of another molecule.
Passive transport - what are the 2 types of secondary transports -eg
Passive transport - movt of A from ↑ to ↓ conc grad. (no energy) Active transport - movt of A against conc grad (need energy) Primary (direct) active transport - uses ATP for conc gradient eg Na+/K+pase Secondary (indirect) active transport - coupled transport - movt of A using passive transport to transport B against its conc grad. -eg-Na⁺ transport glucose against it's conc grad (together) → to enable glucose reabsorption.
Nucleoside
Pentose (5c) sugar linked to nitrogenuos base on 1' carbon by covalent glycosidc bond
What are the 3 classes of hormones? - _____ based - *where are they made?* - solubility - where are their receptors - how do they travel in the blood - *eg-* - *main functions*
Peptide Hormones - receptor is on cell surface - AA based - Made in Rough ER - Water soluble (hydrophilic) - Travel freely through the bloodstream & bind to cell membrane receptors (extracellular) as first messengers → to initiate an (intracellular) second messenger cascade -eg-Insulin/glucagon, vasopressin(ADH), ACTH NOTE: Change protein activity Steroid Hormones -receptor inside cell - Lipid based - Made in Smooth ER - Fat soluble (hydrophobic) - Bind to a carrier protein in the bloodstream (intracellular) OR dissociate from carrier protein & diffuse through plasma membrane to bind to a cytosolic receptor (intracellular) -eg- Adrenal cortex (mineralocorticoid, glucocorticoid) & Sex hormones (androgens, estrogens, progesterone, testosterone) NOTE - regulate gene expression (TransC & L) AA/ Tyrosine Derivative Hormones a) Catecholamines - Function similar to peptide hormones -eg- Epinephrine & Norepinephrine b) Thyroid Hormones - Function similar to steroid hormones -eg- T3 & T4
lysosome vs peroxisome
Peroxisomes are mainly involved in fatty acid metabolism (beta oxidation), and utilize hydrogen peroxide as an electron dump for FADH2. Lysosomes contain acidic enzymes (activated in an environmental pH of 5), and catalyze the breakdown of macromolecules via hydrolysis
Phagocytes - aka - steps from phagocytosis to presentation
Phagocytes = Antigen Presenting Cells (APC) - engulf foreigners via phagocytosis - release lysosome enzyme/H₂O₂ to degrade it - MHC II transfers the degraded proteins to the membrane of the phagocytes. - where it is presented for attack
Diff btw Phospholipids, Transmembrane proteins, Cholesterol - *types of movt*
Phospholipids(major) = for *lateral movt* - Fluid that allows other non-phospholipid stuff to migrate through them to/out of cell Transmembrane proteins= for *vertical movt* - crosses from ext. env (outer leaflet) to cytoplasm (inner leaflet) of phospholipid bilayer Cholesterol = In Euks only - *At ↑T°; it ↓es fluidity* - *At ↓T°; it ↑es fluidity* to prevent rigidity
Ploidy definition - name 3 types of cells - describe # of cells and chromosomes in each - how does sperm and egg differ in amount they contribute to zygote?
Ploidy = # of H/Chrom in the nucleus of a cell Nucleated cell in humans (diploid) = 46C - Somatic (autosome) = 22 pairs =44C - Germ cells (sex cells) = 1 pair = 2C Mature egg OR sperm cell (haploid) = 23C - Somatic (autosome) = 22C - Germ cells (sex cell) = 1C Zygote = diploid = 23 pairs = 46C - one from mother, the other from father
→ Posterior pituitary hormones (oxytocin/vasopressin)
Posterior Pituitary Gland made of Axon projections 1) Oxytocin - Stimulated by Nerve impulses - Uterus: Stimulates contraction during labor - Mammary glands: Milk ejection during breast feeding 2) Vasopressin/ Antidiuretic Hormone (ADH) - Stimulated by Nerve impulses - Promotion of water reabsorption by the kidneys
*Posterior Pituitary Hormones - made of ___ - 2 types - functions - secretion stimulated by? - What happens when there is high solute conc in the body?*
Posterior Pituitary Hormones (OVA) - made of axon projections 1) Oxytocin - uterus stimulate contraction during labor - mammary gland ejects milk during breastfeeding - secretion stimulated by nerve impulses 2) Vasopressin - releases (ADH) to - promote water reabsorption by the kidneys - secretion stimulated by nerve impulses What happens when there is high solute conc in the body? - ↑solute conc → lead to ↑osmolarity - Hypothalamus detects it & nags post puit to release vasopressin (ADH) & ↑thirst - person drinks water which ↑water reabsorption in collecting duct
Journey of polypeptide chain with signal - where is the signal removed Journey of polypeptide chain without signal - where does post translational modification occur - where do the protein designed for secretion packaged & transported to - what happens at the plasma membrane? - eg of post translational modifications
Presence of a signal sequence on growing polypeptide chain → directs the ribosome-protein complex to → Rough ER → Rough ER Lumen (where signal is removed) The peptide is then repackaged into vesicles & sent to → the golgi body (where some post-translational modification occurs) The protein designed for secretion are packaged & transported in vesicles to → plasma membrane. --> These vesicles then fuse with the plasma membrane & release their content outside the cell post-translational modification - glycosylation - disulfide bond formation - phosphorylation - protein cleavage
Origin of replication
Prokaryotes (eg bacteria) - have circular DNA with a single origin of replication in the cytoplasm Eukaryotes (eg yeast and humans) - have linear DNA with multiple origins of replication in the nucleus. An origin of replication expands to form a replication bubble, which contains two replication forks that move apart in opposite directions during DNA synthesis.
Diff btw Prok and Euk Replication - # of Ori, shape, location - what is monocistronic mRNA & polycistronic mRNA? which is prok or euk?
Proks - circular DNA with single ori in cytoplasm - polycistronic mRNA - one transcript(ion initiation site) per multiple genes Euks - linear DNA with multiple ori in nucleus - allows gene to be copied rapidly & efficiently - monocistronic mRNA - one transcript(ion initiation site) per gene
Homodimer:
Protein in which the polypeptide chains of the 2 monomers have the same sequence (number, order, and type) of AAs.
If pH exceeds pI, what happens?
Protein loses protons and becomes negatively charged
Dimer:
Protein that is composed of 2 noncovalently bound polypeptide chains (subunits/monomers)
SDS-PAGE
Proteins analyzed via sodium dodecyl sulfate polyacrylamide gel electrophoresis, used to separate proteins by MW
Isoelectric focusing
Proteins migrate from LOW pH to high pH (anode to cathode*, they *lose protons* and become less positively charged
Resting membrane potential How is the resting membrane potential of a neuron maintained? - why is it important to maintain the unequal conc of ions across the membrane
RMP of neurons is primarily due to - ↑ [K⁺] and ↓ [Na⁺] inside cell vs. outside It is maintained by - Passive transport via protein channels + selective membrane permeability - Active Transport/ATP The following mechanisms maintain RMP; 1) K⁺ leak channels = enables the passive transport of K⁺ out of cell (without energy) 2) Active transport = using ATP to transport molecules against their conc gradient. eg - (Na+K+ ATPase) transport 2 K+ into the cell for every 3 Na+ moved out of the cell. Important for maintaining the unequal conc of ions across the membrane; - without active transport pumps, leakage of ions through the cell membrane would eventually result in equilibration and a membrane potential of 0 mV
RNA Polymerase
RNA polymerases - are responsible for carrying out transcription and must bind DNA at a promoter region for transcription to be initiated.
Random mating
Random mating - increases a population's genetic diversity because of the inherent variations that arise during meiosis (recombination) and sexual reproduction (fusion of gametes). Therefore, the variations or changes to the allele frequencies due to random mating will primarily be beneficial to a population as a whole.
Reading frame
Reading mRNA nucleotides in the correct groupings.
Spliceosome
Recognizes splice donor/acceptor sites; joins the exons to produce transcript with *NO introns*
SDS PAGE under nonreducing conditions
Reducing substances are used to break disulfide bonds in protein,
Autonomic Nervous System
Refers to the collection of neurons and peripheral nerves that regulate involuntary functions of smooth muscle, cardiac muscles and endocrine organs. Two branches: Sympathetic: fight or flight Parasympathetic: Rest and digest
Specific activity
Reflects protein purity (u/mg); ratio of activity of target protein and total protein
Metaphyses
Regions where diaphysi and epiphyses meet
Peptide bond
Resonance stabilized; *rigid and planar* due to partial double-bond character, *rotation restricted*
https://www.khanacademy.org/test-prep/mcat/organ-systems/neuron-membrane-potentials/v/neuron-action-potential-mechanism
Resting membrane potential (RMP): - The membrane potential of the resting neuron is −70 mV (ie, the inside of the neuron is 70 mV more negative than the extracellular space). - The RMP is maintained by the Na+/K+ pump and K+ "leak" channels, which always allow passive diffusion of K+ ions across the membrane. - Ion channels that open or close based on changes in membrane potential (voltage-gated channels) are closed at RMP.
cDNA cloning
Reverse transcriptase generates single strand of cDNA from target mRNA sequence; DNA pol makes 2nd strand
Elongation
Ribosome elongates polypeptide chain by reading each mRNA codon in *5' to 3' direction*, new charged tRNA with anticodon enters *A site*
Eukaryotic translation initiations begins when:?
Ribosomes bind the m7Gpp cap at the 5' end of the mRNA sequence
Histones form ____ with DNA
Salt Bridges b/w (+) AA residues and (-) phosphate groups
Aldosterone
Secreted by the adrenal cortex Promotes Na reabsorption and K secretion, but more Na is reabsorbed than K is secreted resulting in a concentration gradient b/t filtrate and interstitial fluid in the adjacent interstitial space. This causes water to be reabsorbed and increase in blood volume/pressure. It is secreted in response to low BP and elevated K levels.
The sequence below is a portion of an exon of an mRNA transcript. 5′ - UCAAGUGAU - 3′ Write the corresponding DNA coding strand and DNA non- coding strand sequence for this particular transcript?
Sense(coding) DNA - 5′-TCAAGTGAT-3′ mRNA Strand - 5′-UCAAGUGAU-3′ AntiSense(non-coding) DNA -3'-ATCACTTGA-5'
Gel electrophoresis
Separates DNA fragments by *size*, bands visualized via fluorescence or radiolabeling; *LONGER fragments migrate SLOWER* in gel
Types of DNA Mutations
Silent - Single base pair change that does not change the amino acid sequence Missense - Single base pair change that gives rise to a new amino acid Nonsense - Single base pair change that gives rise to a stop codon Insertion - Addition of one or more base pairs into the DNA sequence Deletion - Removal of one or more base pairs from the DNA sequence Duplication - Incorporation of one or more copies of a portion of the DNA sequence Frameshift - Addition or removal of a number of base pairs that is not a multiple of three, resulting in a new reading frame Repeat Expansion - Incorporation of multiple copies of a short base pair sequence in a row
Size-exclusion chromatography
Size-exclusion chromatography - separates compounds based on size; therefore, compounds that are similar in size (eg, theobromine, caffeine) elute together.
Which muscle type is voluntary?
Skeletal -> somatic NS (ACh)
Pathway of Sperm cell:
Spermtagononium Spermtocyte spermatid spermatozoon
Example
Standard Solution; - In the first step, 0.5mL (VT1) of the lipid stock solution was dissolved in 9.5mL (VS1) of solvent to produce a standard solution --> (VF1 = 0.5 + 9.5 = 10 mL). NMR Sample; - In the second step, 0.5 mL (VT2) of the standard solution was dissolved in 0.5 mL (VS2) of solvent for the NMR sample --> (VF2 = 0.5 + 0.5 = 1.0 mL). The DF in this multistep dilution; DF = (VT1/VF1) × (VT2/VF2) DF = (0.5mL/10mL) × (0.5mL/1.0mL) DF = 1/20 × 1/2 = 1/40 Therefore, the lipid extract was diluted by a factor of 40.
Bottleneck events
Sudden environmental changes that *rapidly* decrease # of indv. in population -> reduced genetic diversity
Boiling chips prevents Superheating during Distillation
Superheating happens when a liquid is heated above its boiling point, but it does not boil. Surface tension causes the vapor pressure inside bubbles to increase as they form, causing them to explode at the surface. *Boiling chips are made of nonreactive porous material and provide nucleation sites which gives the bubbles a surface to form on as the liquid is heated. This effect overcomes the surface tension and allows the liquid to boil evenly at its normal boiling temperature, thereby preventing superheating.*
T/F: APs in myelinated axons travel via saltatory conduction
TRUE
T/F: An action potentail is fired in an all-or-none manner based on the cell's membrane potential
TRUE
T/F: If the threshold is reached, voltage-gated ion channels open and the membrane rapidly depolarizes.
TRUE
The Small Intestine → The Large Intestine - Name the 3 parts of the Small Intestine - what are they involved in - function of Intestinal microvilli - Name the 3 parts of the Small Intestine - function - which is connected to the appendix. - Diff btw large & small intestine
The Small Intestine (DJI) = the duodenum, jejunum, and ileum. - duodenum = involved in additional digestion - jejunum + ileum = involved in absorption Intestinal microvilli (small, finger-like projections) - on epithelial lining of small intestine; increase its surface area for large scale digestion & absorption. The Large Intestine = cecum, colon, and rectum. - absorb electrolytes (eg, Na⁺, Cl⁻) & excess water from leftover undigested material → turn to feces → & stored in rectum for excretion - cecum (first segment of the large intestine) is connected to the appendix. Diff btw large & small intestine - LI is not involved in large-scale nutrient digestion and absorption. In contrast, the brush border of the SI is a microvilli-covered epithelial surface where digestion and absorption of nutrients occur.
Immune Defense=innate and adaptive immune systems
The innate immune system - consists of cells poised to attack antigens in a nonspecific manner. These cells include macrophages, dendritic cells, natural killer cells, and granulocytes. This system responds to foreign antigens within minutes to hours and can recognize unique and common motifs present on pathogens. The adaptive immune system - contributes specialized or acquired immunity based on learned recognition of specific antigens. Responses of adaptive immune system can be further subdivided into cell-mediated and humoral immunity: In cell-mediated immunity, - mainly driven by T cells, receptors on immune cells recognize and bind directly to receptors on target cells. In humoral immunity, - B cells produce antibodies specific to a new antigen (primary immune response). These antibodies enable the immune system to respond more quickly if the antigen is encountered later (secondary immune response).
Liver - how are normal functions of the liver severely impacted by disease (3) - functions (6)
The liver = located in upper right side of the abdominal cavity, just below the diaphragm, normal functions of the liver are severely impacted by disease; 1) Ketogenesis: (synthesis of ketone bodies) - for energy metabolism when blood glucose levels are low & glycogen stores are depleted - During fasting, mitochondria within liver cells convert acetyl coenzyme A into ketone bodies, which are then used by the brain to make ATP 2) Detoxification of drugs: Drugs have toxic effects if allowed to accumulate in the body. - liver breakdown and detoxifies drugs 3) Synthesis of plasma proteins: Osmotic pressure is due to plasma proteins that cannot easily cross the capillary membrane. - Osmotic pressure causes a "pulling force" inside capillaries, which balances the pushing force of hydrostatic pressure, helping keep fluid in the vasculature. - The majority of plasma proteins such as albumin are synthesized in the liver. Function of liver cells - Regulation of blood glucose via glycogenesis, glycogenolysis, & gluconeogenesis - Storage of glycogen, minerals (iron) & vitamin - Syn of macromolecules eg plasma protein - (clotting factors & albumin), fats, ketone bodies & cholesterol -Production & secretion of bile - Breakdown/detoxification of drugs & metabolic waste products (bilirubin, ammonia)
what is the functional unit of the kidney? function?(2) Route of blood from renal arteries to ureters
The nephron = functional unit of the kidney, - filters blood by removing waste from blood - reabsorption of useful solutes into the blood. Afferent arteries →Glomerulus →Bowman's capsule →PCT ::: peritubular capillaries →Loop of Henle (desc/asc) →DCT → Collecting duct - Blood is transported from renal arteries to → glomerulus (a bed of capillaries) - BP forces fluid in the blood → Bowman's capsule - This fluid (filtrate) contains small solutes - eg - glucose, ions, and urea - but lacks blood cells and proteins, which remain in circulation. - filtrate passes → Proximal tubule 1) nutrients are reabsorbed from peritubular capillaries that surround PCT into the blood (eg, AAs, vitamins, salts, glucose, water) 2) waste products not filtered by Bowman's capsule are actively secreted from the peritubular capillaries to →The loop of Henle -desc. limb =reabsorption of water via osmosis -asc. limb =reabsorption of ions via osmosis. → Distal conv. tubule (DCT)→ Collecting duct - *Hormonally* regulated reabsorption of Na+ and water by ADH and Aldosterone - The now-concentrated urine is emptied into the ureters→bladder→urethra for excretion.
Route from Nephron to Collecting Tubules
The nephron, the functional unit of the kidney, filters blood by facilitating the secretion of waste products from the blood, as well as the reabsorption of useful solutes back into the blood. Blood is transported from renal arteries to → glomerulus (a bed of capillaries) Blood pressure forces fluid in the blood through the porous glomerular capillaries into → Bowman's capsule This fluid (now called filtrate) contains small solutes such as - glucose, ions, and urea but - lacks blood cells and proteins, which remain in circulation. The filtrate passes from Bowman's capsule into → Proximal tubule →→ Important nutrients (eg, amino acids, vitamins, salts, glucose, water) are reabsorbed from the nephron and incorporated back into the blood through the peritubular capillaries that surround the tubule. Waste products not filtered by Bowman's capsule are actively secreted from the peritubular capillaries into the nephron. →The loop of Henle (a hairpin structure composed of two limbs 1) The descending limb = permeable to water, allowing the passive reabsorption of water via osmosis. 2) The ascending limb = permeable to salt but impermeable to water; this leads to active reabsorption of ions only, which concentrates the medullary interstitial fluid (maintains its saltiness) and prevents its dilution. → Distal convoluted tubule (DCT) - (ADH; vasopressin) and aldosterone promote the reabsorption of water here → Collecting duct - ADH and aldosterone act on the collecting duct in the same way they act on the DCT The now-concentrated urine is emptied into the ureters for excretion.
https://www.khanacademy.org/test-prep/mcat/organ-systems/neural-cells/v/introduction-to-neural-cell-types
The nervous system is composed of - neurons and - glial cells (aka neuroglia) Neurons - conduct electric impulses Glial cells in CNS - Support cells of the CNS. 1) Microglia 2) Oligodendrocytes 3) Astrocytes Glial cells in the PNS 1) Schwann cells 2) Satellite cells
What is the nervous system composed of? What does a neuron do? - Describe the glial cells in CNS (4) and PNS (2) - what is the diff btw Oligodendrocytes & Schwann cells
The nervous system is composed of - neurons and - glial cells (aka neuroglia) Neurons = conduct electric impulses Glial cells in CNS - Support cells of the CNS. 1) Microglia = arise from mesoderm - they act as macrophages by phagocytizing pathogens, damaged cells, and other waste - primary immune cells of the (CNS) 2) Oligodendrocytes = - arise from ectoderm - form myelin sheaths around multiple axons → ↓ion leakage, ↑capacitance, ↑speed of AP along axon 3) Astrocytes = arise from ectoderm - Form blood-brain barrier - regulate blood flow in with synaptic activities - Maintains homeostasis of interstitial space - scaffold/glial scar 4) Ependymal cells = arise from ectoderm - epithelial cells that create barriers by lining the CNS - secrete CSF Glial cells in the PNS - Support cells of the PNS. 1) Schwann cells = arise from ectoderm - similar function to Oligodendrocytes 2) Satellite cells = structural support - provide structural support and supply nutrients to neuron cell bodies in ANS - similar function to astrocytes Unlike oligodendrocytes in the CNS, each Schwann cell forms a myelin sheath for a single neuron in the PNS
Alpha, Beta and Delta cells
The pancreas has endocrine, paracrine, and exocrine functions. - The functional units of the endocrine pancreas are the islets of Langerhans, which are made up of - alpha, beta, and delta cells that secrete different hormones into the blood. Alpha cells produce glucagon, a hormone that promotes glucose release into the blood when blood glucose is low. Alpha cells also exhibit paracrine function, as they are able to inhibit beta cell function in the setting of low blood glucose. Beta cells produce insulin, a hormone that promotes glucose uptake from the blood when blood glucose is high. In this setting, beta cell secretions inhibit neighboring alpha cell function and therefore also exhibit paracrine function. Delta cells produce somatostatin, a hormone that has a generalized inhibitory effect on digestive function and has been shown to suppress insulin and glucagon release. NOTE: - failure in insulin production = impaired endocrine function of pancreatic beta cells - Cells with exocrine function secrete substances (eg, saliva, sweat, enzymes) through a duct and onto an epithelial surface.
The renin-angiotensin system (RAS)
The renin-angiotensin system (RAS) - is a multi-organ molecular cascade activated when BP (or blood volume) falls. When BP drops ↓ 1) The juxtaglomerular (JG) cells - in smooth muscles in the kidney, releases renin 2) Renin (enzyme) cleaves the angiotensinogen to form angiotensin I. 3) Angiotensin-converting enzyme (ACE) then cleaves angiotensin I to form angiotensin II.
- what is the renin-angiotensin system (RAS) - describe what happens after renin is released - where is angiotensinogen made and where does it hangout? - what is ACE? found? function - what triggers the release of hormones? what hormones are released by what? - then what happens b/4 ↑BP?
The renin-angiotensin system (RAS) - is a multi-organ molecular cascade activated when BP (or blood volume) falls. ↓BP/↓blood volume → triggers renin from JG cells which meets → angiotensinogen (made in liver, but inactive in bloodstream) → renin cleaves angiotensinogen to form angiotensin 1 → ACE from lung/ epithelial of cell cleaves →angiotensin 1 to convert to angiotensin 2 angiotensin 2 induces the release of → aldosterone by adrenal cortex (MineralC) + → VasopressinADH by posterior pituitary → Na⁺ & Water are reabsorbed → vasoconstriction occurs ↑blood volume/↑BP
micronuclei
The smaller nucleus which is responsible for cell division and used only during reproduction
The smooth endoplasmic reticulum (SER)
The smooth endoplasmic reticulum (SER) - has varying metabolic functions depending on the cell type; examples include lipid synthesis (testes/ovaries), drug/poison detoxification (liver), and calcium ion storage (muscle).
Peptide hormones, Steroid hormones and AA/Tyrosine derivatives
The solubility of a hormone in water affects how it is transported in the blood and how it exerts its physiological effect on target cells. Hormones are primarily divided into three different classes and their chemical structure determines their water solubility: 1) Peptide hormones (eg, insulin, glucagon) - are composed of AAs linked by peptide bonds and - are made in the rough endoplasmic reticulum (RER). - The overall charge makes peptide hormones water-soluble (hydrophilic), which means they can dissolve in the bloodstream but cannot cross the hydrophobic lipid bilayer of the plasma membrane. - Accordingly, peptide hormones act as first messengers and must bind extracellular receptors to induce a signaling cascade via activation of intracellular second messengers 2) Steroid hormones - are lipid hormones derived from cholesterol and - - - generated in the smooth ER. - These hormones are fat-soluble (hydrophobic) and must therefore be bound to a carrier protein in the bloodstream. - However, their hydrophobicity allows them to diffuse through the plasma membrane (lipid bilayer) and bind their receptor in the cytoplasm or nucleus. Steroid hormones are labeled first messengers as they perform the initial signaling that influences the nuclear transcription and cytoplasmic translation of physiologically required proteins -are able to dissociate from their carrier proteins in the blood and diffuse through the plasma membrane. 3) Tyrosine derivatives - are derived from the amino acid tyrosine. These hormones function similarly to either steroid hormones (eg, thyroid hormones T3 and T4) or peptide hormones (eg, catecholamines epinephrine and norepinephrine). Educational objective: Peptide hormones are amino-acid based, water-soluble molecules that travel freely through the bloodstream and act as first messengers by binding to an extracellular receptor on the target cell membrane, which leads to activation of intracellular second messengers.
Mitochondria DNA - *Functions (3)* - which mitochondria is transmitted to the fetus? *why?* - inherited from whom to whom - how is it diff from nuclear genes
Their main functions include - ATP generation, - heat production, and - beta-oxidation of fatty acids. Only maternal mitochondria are transmitted to the fetus. - because, during fertilization, paternal mitochondria within sperm don't pass into ovum Mitochondrial genes - inherited from affected mothers to offspring females - does not follow Mendelian inheritance patterns Nuclear genes - inherited via autosomal and sex-link - follows Mendelian inheritance patterns, (of inheriting 2 copies of each gene; one from mom & the other from dad)
Extraction of DNA
This procedure often entails the 1) addition of an organic solvent to an aqueous mixture. 2) After gentle shaking, hydrophobic solutes such as lipids separate into the organic layer (non-polar) 3) and polar or charged solutes such as nucleic acids remain in the aqueous layer. To precipitate DNA; 4) Add cold ethanol -*encourage DNA H-bond* 5) Add Na acetate - *forms ionic bonds with DNA, neutralizing it's charge* During extraction procedures, a molecule's charge or polarity may be modified to increase or decrease its affinity for a particular solvent. *Add organic solvent to mixture → organic solute is attracted to organic solvent in organic layer →polar/charge solute remain in aqueous layer*
- What is Threshold potential for the generation of an action potential - why is AP referred to as firing in an "all or nothing" manner When is an action potential generated - When is an action potential generated
Threshold potential - The point where the influx of Na exactly matches the efflux of K An action potential is fires in an *all-or-none* manner based on the cell's membrane potential. - If the threshold is reached, voltage-gated ion channels open and the membrane rapidly depolarizes. - The resting membrane potential is restored by the Na+/K+ pump. Remember there is a higher conc. of Na in the ECF and a higher conc. of K in the ICF. The nanosecond that there is more of an influx of Na than there is an efflux of K, an action potential will be generated.
Topoisomerase
Topoisomerase - introduces negative supercoiling in the DNA double helix ahead of the replication fork to reduce the strain produced by unwinding, which causes positive supercoiling.
Transcription factors
Transcription factors - are proteins that can bind to DNA near gene promoter regions and either increase transcription (activators) or decrease transcription (repressors). Activators facilitate *RNA polymerase* binding to the promoter, and repressors inhibit binding. Educational objective: Transcription factors can upregulate or downregulate transcription by influencing the ability of *RNA polymerase* to bind a promoter. Transcription factors that increase transcription are called activators and facilitate RNA polymerase binding whereas those that decrease transcription are called repressors and inhibit binding.
process by which base pair mismatches between the daughter and parent strands are corrected during DNA replication
What is DNA mismatch repair?
passive transport, ATP, membrane selective permeability
What three factors help maintain the RMP of a neuron
When a nerve impulse is transmitted to a skeletal muscle, what happens to the muscle? - what is the neuromuscular junction? - When an AP reaches the terminal of a motor neuron, which ion is responsible for the release of a neurotransmiter from the presynaptic nerve terminals - what neurotransmitter is released? where -What happens after depolarization of the terminal? - What happens when Calcium level is increased in the terminal?
When a nerve impulse is transmitted - the skeletal muscles contract at the neuromuscular junction, -->the synapse between a skeletal muscle and a motor neuron. When an AP reaches the terminal of a motor neuron, - an influx of Ca²⁺ via voltage-gated Ca²⁺ channels triggers the release of ACh-containing vesicles (exocytosis) into the synaptic cleft. - Released ACh binds to receptors of the motor end plates, - depolarize the innervated muscle fibers - and cause muscle contraction It causes the Ca²⁺ channels in the membrane to open and Ca²⁺ diffuses into the axon terminal from the ECF including that in the synaptic cleft It causes vesicles filled with neurotransmitter to fuse with the presynaptic membrane and release their content into the synaptic cleft
How does glucagon respond to low blood glucose levels?
When blood glucose levels are low (eg, during periods of fasting), -α cells in the pancreas release glucagon and the ANS promotes the release of epinephrine and norepinephrine by the adrenal medulla. Glucagon is a peptide hormone that promotes gluceoneogenesis (the synthesis of glucose from other molecules) and glycogenolysis (the breakdown of glycogen into glucose). Epinephrine and norepinephrine also promote glycogenolysis. Therefore, the overall effect of glucagon, epinephrine, and norepinephrine is to promote the synthesis of glucose and its release into the systemic circulation, thereby correcting the low serum level of glucose.
*How does the body respond to low blood glucose? How does the body respond to high blood glucose? What hormones control glucose?*
When blood glucose ↓ 1) Hypothalamus sends impulses to Adrenal Medulla → to release Epi & NorEpi 2) Concurrently; α cells in pancreas release glucagon (via gluconeogenesis+glycogenolysis) 3) Epi + NorEpi bind to Glucagon at liver 4) Liver releases glucose 5) Blood glucose level ↑ When blood glucose ↑ 1) β cells in pancreas release insulin 2) Fat, liver and muscles take it up/consume/ absorb it (via glycogenesis) 3) triglyceride synthesis (glucose → adipocytes) 4) protein synthesis (plasma AAs → tissues). 5) tissues stores glucose 6) Blood glucose level ↓ Insulin + Glucagon + Epi + NorEpi + Glucocorticoids
X-linked dominant condition
X-linked dominant condition Father - X° Y (affected) Mother - X X - All daughters are affected - All sons are normal Father - X Y Mother - X X° (affected) - All sons and daughters have 50% chance of being affected - Only one copy of the dominant allele of the gene is necessary to inherit an X-linked dominant condition. - These diseases are characterized by a lack of father-son transmission, but all daughters of an affected father are affected. - Affected mothers have a 50% probability of having an affected child.
X-linked recessive conditions
X-linked recessive conditions Father - X° Y (affected) Mother - X X - All daughters are affected - All sons are normal Father - X Y Mother - X X° (carrier) - daughters have 50% chance of being carriers - sons have 50% chance of being affected - Affected males have asymptomatic carrier mothers in X-linked recessive conditions, which are inherited via the X chromosome. Two mutant alleles must be inherited to cause disease in females (XX), but only one mutant allele is required to cause the disease in males (XY).
Zygote = Undergo series of mitotic divisions/cleavages → ___ →eventually lead to __ - what are the 3 different stem cells? . hint (potent) - what do they differentiate into/found? placenta, fetus, or adult? - potency/specialization - which is found in zygotes only - which one can give rise to an entire organism - where do Pluripotent come from?
Zygote = Undergo series of mitotic divisions/cleavages → eventually lead to Fetus Totipotent stem cells → placental + fetus - found only in the zygote (up to 8 cells stage) - Greatest potency/least specialized (can autonomously give rise to an entire organism) - can differentiate into any cell type from an embryo (plancental + fetus) Pluripotent → fetus only - cells of the inner cell mass - can differentiate into any of the 3 germ layers (ie fetus only) Multipotent → fetus + adult - found in both fetus & adult - Least potency/most specialized - can differentiate into cells with many specialized functions ... BUT are limited to a specific lineage (eg can give rise to cells in the nervous system but not other tissues)
Sequence of events from zygote → gastula - diff btw Blastula & Blastocyst - what do each portion of the blastocyst form - what is gastulation?
Zygote→2cells→4cells→Morula →Blastocyst(Trophoblast + Inner cell mass) →Gastula(Endoderm, Mesoderm, Ectoderm) Blastula (non-mammal) /Blastocyst(mammal) - After fertilization, zygote is cleaved into 2 cells → 4 cells →Morula →Blastula (non-mammal) OR Blastocyst (mammal) Blastocyst (mammal) - is cleaved into 2 1) Trophoblast - forms the placenta 2) Inner cell mass - forms the gastula Glastula - Trophoblast + Inner cell mass transform into 3 germ layers via Gastulation Gastulation - Process by which the 3 germ layers form in the developing embryo Germ layers = Endoderm, Mesoderm, Ectoderm - develop into specific structures in body Endoderm(innermost) = digestive organ (liver, pancreas) + lining of digest & respiratory tract Mesoderm(middle) = circulatory + musculoskeletal + urinary + reproductory Ectoderm(outermost) = nervous + integumentary (hair,skin, nails, mouth, nostrils, anus)
Chief Cells
a cell in the stomach that releases pepsinogen and chymosin
10^-7 and 10^-6 differ by...
a factor of 10
ependymal cells
a type of glial cell. These cells line the CSF-filled ventricles in the brain and the central canal of the spinal cord. These are nervous tissue cells with a ciliated simple columnar form much like that of some mucosal epithelial cells.
Humoral Immunity
aantibody-mediated immune response
head of sperm
acrosome and nucleus: acrosome contains lysosome rich enzymes that break the oocyte wall and surrounds the nucleus
polar bodies
are produced after every meiotic division. They are relatively smaller in size due to less cytoplasm compared to the gametocyte that will become the ovum. This is essential so that much of the cytoplasm is available and the chromosomal content is halved at the time of fertilization. The polar bodies will eventually degenerate.
6-8 ppm
aromatic
transverse (T) tubule
brings depolarizing current close to the SR
Tight junctions
cell-cell junction that *prevent H20 and solutes* from diffusing b/w cells across skin cell layer
Desmosomes
cell-cell junction, provides tensile strength to epithelial cell sheets by *anchoring cytoskeletons*
sequences of the pathway of communication from the Brain to the periphery sequences of the pathway of communication between neurons?
cerebral cortex → spinal cord → efferent neurons → interneurons → motor neurons → muscle tissue. dendrites (pre-synaptic neuron) → soma → axon → synapse → dendrites (post-synaptic neuron)
Human cardiac muscle differs from skeletal muscle because it:
contains intercalated discs
Increased ventricular filling _____ vascular resistance (VR)
decreases
Kinases
enzymes that catalyze transfer of PO4 groups from nucleotide di/triphosphates to other (i.e. PKC)
restriction enzymes (endonucleases)
enzymes that cut DNA. Each enzyme will cut DNA at a specific base sequence.
Glucocorticoids
ex: cortisol released by the adrenal cortex act on the liver to stimulate gluconeogenesis and lipolysis.
What's the difference between exocrine and endocrine glands
exocrine: secrete into ducts endocrine: releases products into the bloodstream
Protein levels in a cell are controlled by...
expression and degradation rates
myoglobin
functions as an oxygen-storage unit, providing oxygen to the working muscles + organs have a high concentration of mitochondria found in red muscle & kidney tissue
gel electrophoresis - with PAGE or agarose gel
gel electrophoresis with PAGE - Separates DNA molecules based on size - using a polyacrylamide gel (PAGE) or an agarose gel. The polyacrylamide gel is generally used to analyze proteins or shorter fragments of DNA because it has smaller pores through which the molecules can traverse without falling through.
bacterial transformation
genetic alteration of a cell by the direct uptake and expression of DNA from its surroundings. Transformation occurs naturally in some species of bacteria
Diff btw germ cell and somatic cells - which undergoes mitosis, meiosis? - which is passed on to offsprings or dev after conception? - which have telomeres? - eg
germ cells = sex cell lineage - undergo meiosis to produce gamates - eg sperm, oocytes - passed to offspring via zygote formation in sexual reproduction - inherited and in cells of entire offspring - Have telomeres - expressed somatic cells = non-sex cell lineage -DO NOT undergo meiosis or produce gamates - cannot be passed to offspring; NO zygotes - develop after conception - eg tumor, cancer, skin, muscle, nerve cells - NOT inherited; not in lineage - Have little to no telomeres - but only expressed in cancer cells and cause aging
Q
glutamine
Reducing Sugar Test
if a sugar has a free anomeric carbon not involved in a bond, is a reducing sugar; certain tests will show this
autosomal dominant
if you inherit the abnormal gene from only one parent, you can get the disease
Described an appropriate method of gene deliver
infection of an embryo by a virus modified to carry the gene
protons in ETC are pumped into the
intermembranous space
Do enzymes make reactions kinetically favorable, or thermodynamically favorable?
kinetically favorable
Diff btw knockout gene and *constitutionally active gene*
knockout gene - gene of interest is removed /disrupted /inactivated → leads to NO protein activity constitutionally active gene - gene of interest is transcribed at constant rate regardless of current cell conditions → leads to protein activity
knockout gene model
knockout gene model - the gene of interest is removed, disrupted or inactivated. - This results in absence of protein activity.
Northern Blotting Analysis:
labeled mRNA-> bands on x-ray film, where *band intensity denotes quantity* of mRNA expression; *band location denotes size*
left vs right ventricular wall
left ventricle is thicker and more muscular than the right ventricle because it pumps blood at a higher pressure. The right ventricle is triangular in shape and extends from the tricuspid valve in the right atrium to near the apex of the heart.
DNA annealing depends on three factors
length: shorter is faster pH: closer to physiological pH (7.4) is faster Salt Concentration: higher salt concentration neutralizes electrostatic repulsion between negatively charged phosphate groups in sugar phosphate backbone that can interfere with hydrogen bonding
catalytic efficiency equation influenced by On Menten graph
measure of how well an enzyme facilitates reactions at low substrate concentrations kcat/km allosteric effectors change catalytic efficiency initial slope on menten graph is proportional to catalytic efficiency
Mechanical Digestion of Lipids
mechanical digestion = physically breaks down of food particles into smaller pieces .. eg - Emulsification - chewing in the mouth and - churning in the stomach due to peristaltic waves.
which amino acid corresponds to the eukaryotic start codon?
methionine
Neural crest cells
migrate away from neural tube toward periphery of embryo, give rise to most of PNS
what will happen if a blood clot forms in the venous side of a capillary bed?
net fluid flow in the direction of interstitial spaces will increase
Hardy-Weinburg - Equation - Assumptions - *what is it constant for?*
p²+2pq+q² = 1 p² = freq of homozygotes for dominant disease in population q² = freq of homozygotes for recessive disease in population 2pq = freq of heterozygotes (carrier freq) p + q = 1 p = major allele (homo dominant allele) q = minor allele (homo recessive allele) √ Large population √ Random mating × No natural selection × No new mutations × No gene flow/migration When in H-W eqB - allele freq is constant - heterozygosity is constant
loss of function mutation
result in the gene product having less or no function (being partially or wholly inactivated). When the allele has a complete loss of function (null allele), it is often called an amorph or amorphic mutation
If pentose has OH group at 2' carbon, it is____
ribose
RNA nucleotide composed of:
ribose sugar with phosphate group + nitrogen base
Epiphyses
rounded ends that have joint surfaces covered by articular cartilage
what effect will silencing genes have with the addition of methyl groups to - DNA sequences - mRNA - tRNA
silencing genes by adding methyl groups to - DNA sequences → inhibits transcription - mRNA → inhibits protein translation - tRNA → inhibits protein translation
filtration of the kidney occurs at?
the glomerulus
astrocytes
the most numerous cell type within the central nervous system (CNS) and perform a variety of tasks, from axon guidance and synaptic support, to the control of the blood brain barrier and blood flow.
where do males get their x chromosome from? (mom or dad)
the mother
what is the innermost layer of the GI tract?
the mucosa
isoelectric point
the pH at which an amino acid carries no net electrical charge. The pH at which you will find the pI of an amino acid is the average of the pKas of the carboxyl and amino groups.
Cell Cycle: S Phase
the part of the cell cycle in which DNA is replicated, occurring between G1 phase and G2 phase. Precise and accurate DNA replication is necessary to prevent genetic abnormalities which often lead to cell death or disease.
Thin Layer Chromatograph
uses a solid sheet of polar silica for stationary phase; then run non polar solvent through; polar compounds elute later
HPLC
uses polar stationary phase and non polar mobile phase under high pressure
pulmonary vein
veins that transfer oxygenated blood from the lungs to the heart. The largest pulmonary veins are the four main pulmonary veins, two from each lung that drain into the left atrium of the heart.
compare blood pressure between capillaries and veins
veins would have lower blood pressure
The renin-angiotensin system (RAS) Route
↓BP/↓blood volume → renin from JG cells meets → angiotensinogen (made in liver, but inactive in bloodstream) → renin cleaves angiotensinogen → converts angiotensinogen to angiotensin 1 → ACE from lung/ epithelial of cell convert →angiotensin 1 to angiotensin 2 angiotensin 2 induces the release of →→ aldesterone by adrenal glands →→ ADH by posterior pituitary → Na+ & Water are reabsorbed → vasoconstriction occurs ↑BP/↑blood volume
