Dawn - BIO - Flashcards

Question

In a G protein-coupled receptor system, the G protein: A. is activated by the phosphorylation of GDP into GTP, and is inactivated by the hydrolysis of GTP. B. is activated by the phosphorylation of GDP into GTP, and is inactivated when GTP dissociates and is replaced by GDP. C. is activated when a GDP molecule is exchanged for a GTP molecule, and is inactivated by the hydrolysis of GTP. D. is activated when a GDP molecule is exchanged for a GTP molecule, and is inactivated when GTP dissociates and is replaced by GDP.

Answer 1

- Answer C - G proteins are activated when bound to GTP - this binding occurs when a GDP molecule is exchanged for GTP - Note that GDP is not simply phosphorylated; it is actually replaced by an entirely new GTP - G proteins are rendered inactive by the hydrolysis of GTP

Answer 2

1. Denaturing - Disrupt the interactions between the monomers 2. Reducing - only disrupts disulfide bonds 3. Native - allows you to see the protein in its native state (can tell if something is integrated into a dimer)

Answer 3

Tumors only occur if there is a mutation in here

Answer 4

the protection of glucose in this harsh environment is due to its effects on the diffusion of water (i.e., its osmotic effects). Glucogen stores raises the osmotic pressure of the body fluids and dehydrates cells protecting themm from freezing

Answer 5

Elicits insulin secretion, suppresses glucagon

Answer 6

- Blood plasma and lymph

Answer 7

- Typically found in RBC | - If found in plasma = cause the RBC to rupture or lyse

Answer 8

hypoxia caused by insufficient blood hemoglobin concentration to supply oxygen for exercise at the low oxygen pressure found at high altitudes.

Answer 9

- Myoglobin holds oxygen in muscles and organs, thus, if it is in urine then there is muscle or organ damage

Answer 10

brain stem, cerebellum, and hypothalamus, respectively.

Answer 11

Dilate for short periods of time to enable a sufficient supply of blood (and oxygen) to her cells. Due to the physical exertion of skiing, her cells had an increased need for oxygen.

Answer 12

- Low BP = decrease filtration rate = more time for reabsorption = decreasing amount of substance in urine - High BP = increase filtration ate = less time for reabsorption = increase in urine

Answer 13

A - Both types of cells possess a membrane-embedded electron transport chain capable of generating a H+ gradient, which drives synthesis of ATP via ATP synthase. - This ATP synthesis takes place on the plasma membrane of bacteria and on the inner mitochondrial membrane in human cells.

Answer 14

- When calcium in plasma is high | - Calcitonin reduces bone resorption. Bone resorption occurs when the level of calcium in the blood plasma is low

Answer 15

- Removal of the parathyroid gland would lead to hypocalcemia, a condition of low blood calcium - This would cause increased neuromuscular excitability because of the change in membrane potential, which under normal physiological conditions, is partially kept in balance with extracellular calcium

Answer 16

- Radiating excess body heat into the environment

Answer 17

severe dehydration greatly reduces the volume of filtrate moving through the nephrons of the kidney. If fluid volume is too drastically reduced, the kidney will be unable to effectively do its job of filtering and maintaining homeostasis within bodily fluid

Answer 18

Neutrophils, macrophages, mast cells

Answer 19

T cells --> grow up in thymus

Answer 20

Neutrophils are a component of the innate immune system. They recognize nonspecific molecular motifs common to a wide range of pathogens. This allows them to respond more rapidly than B cells or T cells, which must be generated via clonal expansion from their activated precursors.

Answer 21

In variable region, located on both light and heavy chains

Answer 22

B - The DNA sequence coding for the antibody variable region is developed randomly via recombination of a relatively small number of genes - This process results in a cell with a genome that differs from that of all other somatic cells - Cells that happen to express genes coding for variable regions specific for self antigens are selected against, while those not specific for self antigens are allowed to develop.

Answer 23

- Adaptive immunity is the branch of the immune response that recognizes and responds to specific pathogens. (In contrast, innate immunity provides general, non-pathogen- specific protection.) - Adaptive immunity includes B lymphocytes, which produce antibodies (alternatively termed immunoglobulins). T lymphocytes are also a component of the adaptive immune response, but macrophages are part of innate immunity.

Answer 24

Plasma membrane bc they lack membrane bound organelles (cant use mitochondrial membrane) and not all of them have cell walls

Answer 25

1. transformation - occurs when bacteria pick up genetic material from their surroundings - Conjunction = bacterium exchanges genetic material with another cell via specialized sex pilus 2. Transduction - Bacteriophage transfers genetic material from one bacterial cell to another during infection

Answer 26

- NO change in population size, but INCREASE in genetic diversity - Hfr strain can only mate with other females (F-) because they lack factor

Answer 27

BOTH - first undergo transcription into RNA using RNA polymerase; as their name implies, they are then reverse transcribed back into DNA and placed in a distinct location elsewhere in the genome. - Class I - COPY and paste (so it makes an additional copy of the transposon) - Class II - CUT and paste - so no additional copy

Answer 28

C - bc Most viral capsids are composed of repeated identical monomers, reducing the need for a large genome containing multiple different genes for structurally distinct capsid proteins.

Answer 29

- Protein aggregation problems | - ie: if missing heat shock activity (whcih helps fix misfolded proteins) then likely not a prion issue

Answer 30

C bc its efferent not afferent and the others dont end in skeletal muscle

Answer 31

D bc depolarization means influx of Na+ and muscle activation means release of Ca2+ from sarcoplasmic reticulum

Answer 32

D - A peptide is an amide linkage between the amine group of one amino acid and the carboxylic acid group of another. Amides are stable because they exhibit resonance stabilization between the lone pair on the nitrogen and the double-bond in the carbonyl group, as shown below.

Answer 33

D - note A is true but doesnt answer the question because it talks about transport not number of genes per mRNA transcript

Answer 34

"B is correct. This is a question of definition; only hybridization describes a process of binding through complementary nucleotides. A: Polymerization is the process by which nucleotides are strung together to form a single-stranded RNA strand, not the joining of two complementary strands."

Answer 35

"C is correct. As a kinase, PKA functions to add a phosphate group to its substrate. The opposite of this activity is the removal of phosphate from a substrate, a function which is performed by phosphatase enzymes. A: Phosphorylase enzymes also add phosphate groups to their substrates, so the “general effect” of a phosphorylase on its substrate is similar to that of a kinase. Specifically, kinases transfer phosphate groups from a high-energy source (usually ATP) to their substrates, while phosphorylases transfer phosphate from an inorganic phosphate source."

Answer 36

"B is correct. Aldosterone is released from the adrenal cortex in response to low blood pressure. Its primary function is to increase sodium reabsorption in the distal tubule and collecting duct. Aldosterone upregulates the sodium-potassium pumps along the lining of the nephron, pumping three sodium ions OUT of the nephron lining (and toward the blood) for every two potassium ions it pumps IN (toward the nephron and away from the blood). Since we have a net solute movement out of the nephron, aldosterone also increases the gradient that favors water reabsorption. A: Although aldosterone causes an increase in passive water reabsorption, it does not do so through regulation of aquaporin channels. That’s the effect of ADH."

Answer 37

cytoplasmic components

Answer 38

C is correct. A double-crossover event is one in which chromosomal arms of homologous chromosomes cross over in two different places along the arm.  This results in a section in the middle of each chromosome being exchanged

Answer 39

High glucose levels in the blood

Answer 40

- Blood and cytosol are made of lots of water so if the drug is hydrophilic it will have a hard time moving through the blood stream

Answer 41

"- At moderate to high temperatures (including normal physiological temperature), cholesterol increases the rigidity of cell membranes by attracting adjacent phospholipid tails - at very low temperatures; cholesterol fills in the gaps between phospholipid tails, preventing the membrane from becoming too rigid.)"

Answer 42

"- At moderate to high temperatures (including normal physiological temperature), cholesterol increases the rigidity of cell membranes by attracting adjacent phospholipid tails - at very low temperatures; cholesterol fills in the gaps between phospholipid tails, preventing the membrane from becoming too rigid.)"

Answer 43

"B - Analogous structures are those structures that evolved independently to carry out the same function - Homologous structures are those that have a similar evolutionary history, arising from the same source, even if they now have different functions."

Answer 44

"C is correct. - During sedimentation analysis, a tube with sucrose solution is covered with a layer which contains the sample molecules of interest. - The tube is then centrifuged (spun at high speed) for several hours; the sucrose gradient remains stable. - Depending on the sizes/molecular weights of the macromolecules in the sample, they migrate through the gradient at different rates: lighter molecules will move less quickly than denser molecules. - Each molecular type will eventually form a discrete band at its isopycnic point, where its density equals that of the sucrose gradient. - The volumes of the subunits are additive which means that the buoyant force on subunits is additive. The masses are additive so the gravitational force is additive as well. - The drag force has the most to do with the shape of the falling particle, which will change when the subunits come together."

Answer 45

B is correct. rRNA and proteins combine to form the nucleoprotein called a ribosome. The ribosome serves as the site and carries the enzymes necessary for protein synthesis. Thus, rRNA forms most of the structure of ribosomes.

Answer 46

"- Phosphodiester bonds connect individual nucleotide monomers to form nucleic acid polymers, such as DNA or RNA. - Polypeptides are composed of amino acids joined by peptide bonds - Polysaccharides are composed of monosaccharide monomers joined by glycosidic linkages - Polyamines are molecules with two or more primary amino groups, but they do not necessarily contain phosphodiester bonds like nucleic acids."

Answer 47

"D - While DNA is used primarily for transmitting genetic information, RNA is capable of a greater diversity of functions (eliminate choice B). - One of these is the ability for ribozymes, which are composed of RNA, to catalyze chemical reactions. - DNA cannot act as a catalyst. - Note also that ribose, the sugar found in RNA, contains one more -OH group than deoxyribose, the sugar present in DNA. DNA is typically double-stranded, meaning that RNA is more (not less) likely to be single-stranded."

Answer 48

"D - Ribonucleosides contain ribose, while deoxyribonucleosides contain deoxyribose. - Ribose does contain a 3' -OH group, but so does deoxyribose; it is the 2' -OH group that deoxyribose lacks."

Answer 49

"zero - Ms-1 1st - s-1 2nd M-1s-1 3rd M-2s-2"

Answer 50

"C – In order to determine quaternary (i.e. subunit) structure, the conditions must be able to target and then break up the links (e.g. disulfide links) holding quaternary structure together. - Under reducing conditions interactions between polypeptides is disrupted. However, under non-reducing conditions, the interactions are preserved. A. Native gels means the proteins runs as it exists in vivo, meaning all of its protein structure remains intact."

Answer 51

"D is correct. - A protein rich in lysine (a basic amino acid) will have a higher isoelectric point (pI) than a protein largely formed from hydrophobic residues. - A higher pI means the protein will tend to be more positively charged and will thus move closer to the negative end of the gel. - In electrophoresis, the apparatus functions like an electrolytic cell, meaning that the anode is positive and the cathode is negative. - The lysine-rich protein, which is positively charged at physiological pH, then, will move closer to the negatively-charged cathode. - Note that in isoelectric focusing, a protein or amino acid always becomes stationary when it has reached the portion of the gel corresponding to its isoelectric point."

Answer 52

A is correct. This question is asking us to determine the state of a protein at a pH below its isoelectric point. We can see from Figure 1 that at a pH below its pI, the protein will move toward the right, toward the cathode. Since the cathode is negative, this means that the protein must be positive.

Answer 53

A is correct. We know that alanine has no acidic or basic side groups, but (like all amino acids) it does have an amino terminus and a carboxy terminus that contribute to the pI calculation. A basic understanding of pI leads us to the recognition that in an amino acid like alanine, we can simply take the average of the pKas of the amine and carboxy termini. This gives us (2 + 9) / 2 = 5.5.

Answer 54

"1. Lysogenic phase - the virus is dormant and its DNA is integrated with that of the host’s genome - All of the daughter cells from the initial infected cell will carry the virus’s genetic information - At some point, the virus will be triggered and will hijack the cellular machinery in order to produce viral progeny - This marks the entry into the lytic phase. 2. Lytic phase - host cells are actively producing more virus progeny and are being lysed to so that the viruses can go on to infect other cells."

Answer 55

D is correct. Eukaryotic protein synthesis occurs on 80S ribosomes. These are distinct in their subunit composition from 70S ribosomes, which are found exclusively in prokaryotes. "Phage" is short for "bacteriophage," meaning a virus that reproduces using the host prokaryotic machinery.

Answer 56

"1. Excitatory - Glutamate, aspartate, nitric oxide 2. Inhibitory - GABA, glycine, serotonin, dopamine 3. Both - ACh, NE"

Answer 57

"A | - PCR uses DNA primers, so we can eliminate C and D because they contain uracil (U) and are therefore RNA. "

Answer 58

"different functions could be caused by transcription that began at different (alternate) promoter regions within the exon which encodes them - Note: they would have different primary AA sequences because they have different physiological effects"

Answer 59

C is correct. Eukaryotic DNA polymerases ε and δ are principally responsible for the elongation of the leading and lagging strands, respectively, during DNA replication. Both polymerases read the parental nucleotide template in the 3’ → 5’ direction, adding nucleotides to the growing strand in the 5’→ 3’ (antiparallel) direction. This makes choice C an incorrect statement and the correct answer.

Answer 60

"A is correct. - Photoreactivation is a prokaryotic process (still used in some eukaryotes) to reverse damage done by UV light; humans use a separate process. - Base excision repair is seen in both prokaryotes and eukaryotes - Homologous recombination is only seen in eukaryotes, which possess chromosomes. "

Answer 61

"1. Ectoderm - primarily gives rise to the nervous system and epidermis (skin), as well as related structures like hair, nails, and sweat glands, and the linings of the mouth, anus, and nostrils 2. Mesoderm - musculature, connective tissue (including blood, bone, and cartilage), the gonads, the kidneys, and the adrenal cortex 3. Endoderm - interior linings of the body, including the linings of the gastrointestinal system, the pancreas and part of the liver, the urinary bladder and part of the urethra, and the lungs."

Answer 62

"1. Insulin is a peptide hormone released by the beta cells of the pancreas in response to high blood glucose levels - Reduce blood glucose levels by promoting the transport of glucose into cells via insulin receptors, which activate membrane-bound glucose transporters - The glucose transported into the cell can be used immediately through glycolysis - Alternatively, muscle and liver cells can store the glucose as glycogen, and adipocytes (fat cells) can mobilize fatty acids to store downstream byproducts of glucose metabolism in the form of triglycerides. - nsulin upregulates all those processes, as well as protein synthesis. 2. Glucagon is a peptide hormone released by the alpha cells of the pancreas, and its mechanism and function are essentially the opposite of insulin. - Glucagon is released in response to low glucose levels and has the effect of increasing blood glucose levels by promoting glycogenolysis and gluconeogenesis in liver cells. "

Answer 63

"1. Amphipathic - has both hydrophobic and hydrophilic portions 2. Amphoteric - Able to act as an acid or a base "

Answer 64

"- Fat: Vitamin K, A, D, E (thus will be taken up from the small intestine with the help of bile) - water: vitamins B and C"

Answer 65

"1. Binding of ligand to GCPR's EXTRAcellular domain causes receptor activation 2. Displacement of GDP by GTP is necessary for activating Gs proteins and for reaction with adenylyl cyclase "

Answer 66

"- GTP binding induces a conformational change required for interaction of Gs protein and adenylyl cyclase. - NOTE: GTP hydrolysis inactiates Gs protein and causes its dissociation from adenylyl cyclase "

Answer 67

"B is correct. This question asks us to determine which aneuploidy will be most detrimental. The primary reason certain chromosomal disorders are deadly is because the genes on the chromosome that are lacked or in excess impact fetal survival. The more genes a chromosome has, the more likely that an aneuploidy of that chromosome will be fatal to the fetus. Trisomy 21 is survivable and results in Down's syndrome, while Trisomy 14 is incompatible with life. A: The gene density is not as important as the quantity of genes lost or copied. C: There is no reason to think that chromosome 21 has more “essential” genes than chromosome 14. D: The quantity of extra DNA would not be a problem more so than the overexpression of the genes on the extra DNA. "

Answer 68

I thought km stayed the same and vmax changed for competitive inhibitor --> got it fucking backwards again fml

Answer 69

C is correct. If the scientists wanted to prevent cellular replication, they would need to halt cell division (mitosis). Interphase is the stage of the cell life cycle (shown below) that occurs between rounds of division.

Answer 70

"- Protein modifications must be post-translational modifications. 1. Post translational modifications take place in the interior of the endoplasmic reticulum or the cytoplasm 2. post-transcriptional modifications (those performed on mRNA) occur in the nucleus; these include the addition of the poly(A) tail, the addition of the 5’ cap, and splicing."

Answer 71

D is correct. In each case, you should draw the Lewis dot structure. In methanol (CH3OH), four atoms form single bonds with the carbon atom, which is sp3 hybridized. The oxygen atom has two single bonds, one to carbon and one to hydrogen, as well as two lone pairs of electrons; it therefore has sp3 hybridization as well. Neither atom has sp2 hybridization. The structure of methanol is shown below.

Answer 72

For the most part, bacteria lack introns, whereas large eukaryotic genes usually contain several introns. A large, eukaryotic gene without introns suggests a bacterial origin.

Answer 73

"B is correct. - Membrane transport is most likely to be affected if the disruption occurs in components that span the entire membrane. - Transmembrane proteins (many of which are glycoproteins) are the only component listed that pass all the way through the cell membrane and facilitate membrane transport. - Glycolipids act to provide energy and also serve as markers for cellular recognition. - Phospholipids are a structural component of the membrane and are not involved in traffic/transport."

Answer 74

C - based on mass this is the smallest

Answer 75

"- siRNA is only able to bind to other RNA strands, not to DNA or protein - it must interfere with gene expression after transcription has already occurred, but before translation - Prevents the translation of mRNA corresponding to the target protein "

Answer 76

"C is correct. This question requires outside knowledge about glucose metabolism. If cells cannot take up glucose, it will remain in the blood and eventually be excreted in the urine when it builds up to the point that it cannot be reabsorbed by the nephron. In a state of extended hyperglycemia, the body relies on fat metabolism to generate energy, which produces ketone bodies that are also excreted in the urine. Therefore, Roman numerals II and III are correct. I: Proteins in the urine are not the result of hyperglycemia, but rather damage to the glomerulus. Thus, although individuals with diabetes can have protein in their urine, it is not the direct result of elevated glucose levels, but instead a later complication."

Answer 77

"C - mitosis results in diploid daughter cells (46 chromosomes), while meiosis results in haploid cells(23 chromosomes) to produce gametes."

Answer 78

"For amino acids with acidic side chains, the isoelectric point is the average of the two most acidic (lowest) pKa's. pKa = (8.18 + 1.96) / 2 = 10/2 or approximately 5"

Answer 79

"1. Western - identify proteins 2. Northern - identify RNA sequences 3. Southern - identify DNA sequences"

Answer 80

"1. PCR - laboratory DNA replication - uses a thermostable DNA polymerase and successive cycles of denaturation, annealing of primers, and extension of a new complementary strand to produce many copies of a sequence of interest 2. Edman degradation - Sequence proteins via successive cleaving of terminal AA residues"

Answer 81

"- All immunoassays operate by using antibodies cultured from antibody producing cells that can bind with great specificity to a protein antigen of interest 1. RIA - radioimmunoassay - protein concentration can be assessed indirectly by measuring the extent to which the protein competes with radioactively labeled standard for antibody binding sites 2. ELISA - enzyme-linked immunosorbent assay - solid-phase enzyme immunoassay that detects the presence of an antigen - First, a sample containing an unknown amount of antigen is applied to a solid-phase supporting structure. - Then the antigen contained in the sample becomes attached to the solid support, a specific detection antibody is applied to, and binds with, the antigen. - Then the antibody is then covalently linked to an enzyme directly or through a secondary antibody that is conjugated with an enzyme - Between steps, the plate is often washed with a detergent to rinse unbound proteins or antibodies. - Following addition of the enzyme’s substrate, a reaction occurs that produces a visualizable signal. The intensity of this signal is related to the quantity of protein antigen present in the original sample."

Answer 82

"1. lipid-soluble molecules are able to pass through | 2. while hydrophilic molecules are not"

Answer 83

"- Thin layer chromatography separates and purifies compounds and can be used to identify - Separates based on polarity (like dissolves like) - Traditionally has a polar stationary phase (silica) and a nonpolar mobile phase (more polar = travel shorter distance) "

Answer 84

"- Column chromatography - Can be Negatively (cation) or positively (anion) charged stationary phase - Will attract opposite charge, repel oppsite charge and not interact with neutral charges - buffer with a pH > pI of the target protein, the protein will carry a net negative charge; so a positively charged anion exchange resin is chosen to capture this protein. - buffer with a pH < pI of the target protein, the protein will carry a positive net charge; so a negatively-charged cation exchange resin is chosen. "

Answer 85

"- Column chromatography - Negatively charged stationary phase - Will attract opposite charge, repel oppsite charge and not interact with neutral charges "

Answer 86

"- Stationary phase of the column is hydrophobic and the mobile phase is hydrophilic - Polar molecules will interact more strongly with the mobile phase and elute more quickly than nonpolar species (shorter retention time) - THIS IS OPPOSITE OF NORMAL (typically polar has strong interaction with stationary phase and has a longer retention time) "

Answer 87

"H2C=CH-OH | - They are able to tautomerize in aqueous solution to form a more stable keto which looks like H3C-CH=O"

Answer 88

"- Sublimation = conversion from solid to gas | - NO temp change because its absorbing all the energy to achieve the phase change "

Answer 89

``` "ΔG= ΔG° + RTln(Q) = -RTln(K) + RTln(Q) ΔG = ΔH – TΔS" ```

Answer 90

- Fold spontaneously because they are stabilized by hydrogen bonds formed by adjacent beta strands

Answer 91

"- Amide bonds! | - Carboxylic acid group of one amino acid reacts with the amine group of another amino acid "

Answer 92

- Want a ΔG as close to zero as possible

Answer 93

NADH, ATP, creatine phosphate, acetyl-CoA

Answer 94

"1. First Law of Thermodynamics states that heat is a form of energy, and thermodynamic processes are therefore subject to the principle of conservation of energy - AKA heat energy cannot be created or destroyed 2. Second law of thermodynamics states that a spontaneous reaction or cyclic process must yield a net entropy increase. - AKA the entropy of the universe should be continually rising 3. Third law of thermodynamics states that if something becomes 0°K or -273.15°C or -459.67°F then its atoms stop moving (entropy of any pure substance in thermodynamic equilibrium approaches zero as the temperature approaches zero) 4. Zeroth law - If two systems are each in thermal equilibrium with a third, they are also in thermal equilibrium with each other - AKA This temperature is called absolute zero."

Answer 95

- Hydrolysis! add H2O

Answer 96

"- NADH! - 2.5 ATP molecules | - FADH2 enters one complex later than NADH so it only contributes 1.5 ATP"

Answer 97

D because gonadotropin-releasing hormone regulates pituitary gonadotropin (luteinizing hormone and follicle-stimulating hormone) secretion. Thus, if gonadotropin-releasing hormone is not able to regulate luteinizing hormone and follicle-stimulating hormone secretion from the pituitary, the reproductive axis will remain quiescent

Answer 98

C because during DNA replication, helicase catalyzes the unwinding and separation of the parental DNA strands, so that each can be replicated.

Answer 99

"1. Decrease transport of Ca2+ to the extracellular environment. 2. Increase availability of intracellular Ca2+ to bind to troponin. 3. Increase overall Ca2+ stores in the sarcoplasmic reticulum."

Answer 100

``` C because The Na+K+ ATPase is an example of primary active transport - Cardiac glycosides are a class of organic compounds that increase the output force of the heart and increase its rate of contractions by acting on the cellular sodium-potassium ATPase pump ```

Answer 101

"Basic - Lysine (K), Histidine (H), Arginine (R) | Acidic - Aspartic acid (D), Glutamic acid (E) "

Answer 102

"- Promotes transcription by modifying chromatin structure | - Decrease coiling "

Answer 103

"1. Fasting - glycogen breakdown and gluconeogenesis | 2. Continued fasting - production of ketone bodies by sustained fatty acid oxidation "

Answer 104

"- The sympathetic branch of the autonomic nervous system - Secretes epinephrine and norepinephrine in RESPONSE TO short term stress - NOTE: REACTION to short term stress are mediated by the sympathetic branch of the autonomic NS "

Answer 105

osmotic pressure is directly proportional to solute concentration. Since the osmotic pressure of blood is one-fourth that of ocean water, the solute concentration is also one-fourth that of ocean water, or 0.25 × 0.50 M = 0.12 M.

Answer 106

"1.Glycolysis - Breakdown of glucose into 2 pyruvate 2. Glycogenesis - formation of glucogen from glucose 3. Glycogenolysis - breakdown of glycogen to release glucose 4. Gluconeogenesis- formation of glucose from noncarbohydrate (aka opposite of glycolysis) "

Answer 107

- Must be a palindrome!

Answer 108

"1. Complex I - NADH coenzyme Q reductase - Coenzyme Q - ubiquinone 2. Complex II - Succinate dehydrogenase 3. Complex III - cytochrome bc1 complex aka CoQH2-cytochrome c reductase - Cytochrone C - carries two molecules 4. Complex IV - cytochrome c oxidase"

Answer 109

Succinyl-CoA synthetase

Answer 110

"- Imprinted genes are expressed in a parent specific manner - genes that undergo genomic imprinting, the parent of origin is often marked, or “stamped,” on the gene during the formation of egg and sperm cells (ie: the one that is turned on) "

Answer 111

coding for or carrying a transcriptase that copies viral RNA

Answer 112

Epithelial

Answer 113

Ribosome! - rough ER is the site of much protein synthesis - smooth ER is the site of lipid synthesis - AND the rough ER is covered in ribosomes while the smooth ER is not

Answer 114

- Causes them to make an alternative secondary structure bc of the charge (wont be alpha or beta)

Answer 115

1. CNS - Oligodendrocytes | 2. PNS - Schwann cells

Answer 116

B is correct. This question effectively asks us to determine the effects of increased GH secretion. It is not likely that this would stimulate more GHRH production because GHRH acts to stimulate GH secretion. This type of positive feedback loop is not a common biological process. A. GH stimulates growth. C. Calcitonin would not likely be directly affected at first, but it is more likely to occur than choice B because GH takes calcium from the blood. D. Somatotropes secrete GH. It is likely that there will be less activity of prostaglandins on somatotropes because prostaglandins stimulate GH secretion.

Answer 117

B is correct. In order for the excessive growth described in the question stem to occur, the overstimulation of growth process must have occurred prior to the fusing of bone growth (i.e. epiphyseal) plates, which occurs after puberty.

Answer 118

- REduction in basal metabolic rate, also less secretion of ACTH

Answer 119

Pineal gland! Melatonin secretion is stimulated by darkness and inhibited by light

Answer 120

- Na retention, K secretion, H2O retention

Answer 121

"- Pumps protons from mitochondrial matrix to intermembrane space to generate electrochemical gradient across the inner mitochondrial mambrane - any event that causes the dissipation of the electrochemical gradient across the inner mitochondrial membrane will result in decreased level of protons in mitochondrial intermembrane space."

Answer 122

A is correct. This question asks us to determine the effects of hyperventilation. During hyperventilation, there is a loss of CO2 and an increase in O2 in the blood. Hypoxia is another term for oxygen deprivation

Answer 123

"Carbon and hydrogen in its forumla - Must have covalent bond between a carbon and hydrogen - Typically have R-COOH structure - Carbonic acid is NOT an organic compound "

Answer 124

"1. Aldosterone released from adrenal cortex 2. Aldosterone targets kidneys 3. K+ secretion increases and Na reabsorption increases 4. Blood Na/K levels normalize 5. Increased aldosterone will inhibit renin production and cause high BP"

Answer 125

"C is correct. Transduction is a form of horizontal gene transfer in bacteria in which bacteriophages (viruses that infect bacteria) transmit genomic material. A: Transformation involves direct uptake of genetic material from the environment and is not mediated by viruses. B: Conjugation is a horizontal gene transfer process in bacteria in which plasmid DNA is transferred from one bacterium to another through a pilus. Viruses are not involved. D: Binary fission is how bacteria reproduce asexually."

Answer 126

the G0 phase (shown below along with the rest of the cell cycle) entails. This is the state that a cell will enter if it does not need to divide. Since epithelial cells are those that divide the most out of the options, they will not be in G0

Answer 127

"A is correct. Certain tissues in the body are able to regenerate due to the ability of their cells to undergo mitosis when necessary. Skin grows by mitosis when injured; however, if control of this growth is lost, then conditions such as keloids of skin cancer (melanoma) may result. B: Meiosis is used to generate sex cells (gametes), not somatic cells."

Answer 128

"1. Outer membrane 2. Intermembrane space 3. Inner membrane 4. Matrix "

Answer 129

B is correct. This question is asking us to determine the weight of a strand of genetic material that contains uracil instead of thymine. We are told in the passage that uracil can be formed from the direct deamination of cytosine, while thymine is formed from a deamination and a methylation. Therefore, thymine weighs more than uracil by one methyl group. The ribose ring of RNA will also be heavier than the deoxyribose ring of DNA because the DNA is "de-oxy," meaning it lacks the 2' hydroxyl group that is present on the ribose of RNA.

Answer 130

"- If the protein has lots of charged residues on its own - If there are enough positive charges, the negative charge of the protein will not be as great as anticipated and the molecule will travel a smaller distance, which, to the individual running the assay, usually means the mass of the protein is greater and would lead to the discrepancy."

Answer 131

Binds together pieces of the lagging strand

Answer 132

"1. Passive immunity - transfer of active humoral immunity in the form of ready-made antibodies, from one individual to another. 2. Natural immunity - present in the individual at birth, prior to exposure to a pathogen or antigen, and that includes intact skin, salivary enzymes, neutrophils, natural killer cells, and complement."

Answer 133

"1. Cell-mediated immunity - response that does not involve antibodies, but rather involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen. 2. The innate (non-specific) immune system - anatomical barriers, secretory molecules, and cellular components. Among the mechanical anatomical barriers are the skin and internal epithelial layers, the movement of the intestines, and the oscillation of bronchopulmonary cilia."

Answer 134

- Nonpolar because it has to be in contact witht he nonpolar tails fo the phospholipid molecules

Answer 135

DNA virus!

Answer 136

What is cell differentiation mediated by?

Answer 137

Net fluid flow in the direction of interstitial spaces will increase.

Answer 138

"Hydrogen ions! | - Bicarbonate ions maintain proper physiological pH, or the level of hydrogen ions "

Answer 139

To maintain isotonicity of the dialysate solution with blood

Answer 140

200 nm (so cant see anything smaller than that)

Answer 141

"Viruses take advantage of the elaborate intracellular mechanisms of the host cell using them to make more virus particles. - To do this they need intact host cells. Non-cellular media such as the nutrient broths and suspensions will not support culture of viruses"

Answer 142

"1. Transcription is copying - taking DNA and making an RNA copy 2. Translation is changing the language.- translation refers to taking the RNA, a series of nucleotides, and putting it into protein language, a series of amino acids - Some viruses have a genome consisting of RNA and this can be directly translated by the ribosome. Others use DNA as the genetic material and require transcription as well. Both, however, ultimately make proteins by translating their specific RNAs into protein"

Answer 143

In capillaries, and even lower in veins!

Answer 144

"- Increased glomerular filtration rate - An increase to the systemic blood pressure would initially increase the glomerular capillary blood pressure, which would increase the glomerular filtration rate. - Without a corresponding increase in the rate of tubular reabsorption of water, this would lead to an increase in urine output"

Answer 145

"- If an ulcer penetrated the walls of the intestine, this would allow the contents of the gastrointestinal tract to enter the peritoneal cavity. - Membranes surround this cavity, which would prevent further transport of the gastrointestinal contents through the rest of the body - An ulcer in the small intestine would not allow the contents to enter the lumen because this is the normal place in which the contents are found."

Answer 146

"1. Calcitonin - increases calcium UPTAKE from the blood (ie: more into bones) - Inhibits osteoporosis (bone break down) - Osteoblasts form bone 2. Parathyroid hormone - decreases calcium uptake from blood (ie: breaks down bones) - Inhibited by high levels of calcium - parathroid - RID of calcium - Osteoclasts break them down "

Answer 147

"1. Western blot - proteins are run on a gel using electrophoresis, transferred to a nitrocellulose or similar membrane, and finally washed with an antibody marker. - It is typically used to determine the identity of particular proteins present in a sample and can sort these proteins by molecular weight. 2. Northern Blot - Detects presence of mRNA NOT protein 3. Southern blot - Detects DNA sequences"

Answer 148

a five-carbon sugar, a nitrogenous base, and one to three phosphate groups.

Answer 149

B is correct. DNA polymerase is incapable of starting initiation, and instead is only able to elongate existing strands. Without a primer, DNA polymerase would have no initial position to bind to

Answer 150

DNA sequence analyzing the sequence of the associated gene.

Answer 151

"DNA contains a more stable sugar than RNA. II. RNA can catalyze biochemical reactions, but DNA cannot - DNA contains a deoxyribose sugar, while RNA is formed with ribose, a sugar with a free 2’ hydroxyl group. - This small difference makes RNA more reactive and unstable; for this reason, it rapidly degrades once exiting the nucleus. Ribozymes are RNA-based enzymes, and as such, are able to that can catalyze biochemical reactions. Virtually all other enzymes are composed of protein."

Answer 152

A is correct. Allosteric inhibition involves the binding of a molecule at a site other than the active site. This binding causes a conformational change in the enzyme, rendering it unable to bind its original substrates. If the enzyme in the question stem is suddenly able to allosterically bind several new molecules, and those new substrates are present in the reaction environment along with the original substrate, then a significant proportion of the enzymes will be unable to carry out the original reaction.

Answer 153

"C is correct. Prokaryotic translation does rely on the presence of several release factors. In contrast, eukaryotes need only one such factor: eukaryotic translation termination factor 1 (eRF1). This answer can also be found through elimination. A, B: These are characteristics of both eukaryotic and prokaryotic translation. D: While both forms of translation certainly require ribosomes, remember that prokaryotes entirely lack membrane-bound organelles. For this reason, a prokaryotic cell would not have a rough endoplasmic reticulum."

Answer 154

A is correct. To ensure the proper termination of translation, stop codons are only recognized by protein release factors. In other words, no tRNA molecules bind to these codons, and they do not correspond to any amino acid residues. If tRNAs were able to recognize such codons, the translational machinery would be able to bypass them and produce inappropriately long protein chains.

Answer 155

"1. Euchromatin is associated with increased levels of transcription - Euchromatin is less tightly packed around nucleosomes 2. Heterochromatin is related to the downregulation of transcription. - densely organized and less transcriptionally active "

Answer 156

"1. Nuclear localization signal - Not likely for transmembrane proteins - Allows proteins to enter the nucleus 2. Signal sequence - Transmembrane proteins dock at rough ER"

Answer 157

Medullary portion of the collecting duct

Answer 158

B because free energy is a thermodynamic quantity and is NOT a kinetic property. Activity is a kinetic property

Answer 159

"1. Small uncharged | 2. Large, flat and uncharged/nonpolar "

Answer 160

passive flow due to a pressure difference

Answer 161

A, because acetyl coenzyme A is the main input of the citric acid cycle.

Answer 162

Endothelial cells

Answer 163

C because the passage states that aldosterone causes excretion of K+. Therefore, aldosterone deficiency will not lead to a decrease in serum levels of K+ ions.

Answer 164

B because ACTH stimulates the adrenal cortex to secrete glucocorticoids. According to the passage, Addison’s disease occurs when cells of the adrenal cortex are destroyed, rendering them unable to secrete glucocorticoids. As part of a hormone cascade pathway, ACTH secretion is expected to be higher than normal in a patient with Addison’s disease to attempt to stimulate the adrenal cortex.

Answer 165

C because the stem states that exercise promotes the insulin-independent uptake of glucose and thus it will reduce blood glucose levels both in patients with impaired production of insulin (type 1 diabetes), and in patients who do not respond to insulin (type 2 diabetes)

Answer 166

Phosphodiester

Answer 167

C because ATP, the end product of glycolysis, downregulates through feedback inhibition the activity of phosphofructokinase-1 by binding to a regulatory site other than the active site of the enzyme (allosteric regulation). In contrast, competitive inhibition involves competition for binding to the active site.

Answer 168

"1. Gram negative - thinner layer of peptidoglycan but additional outer layer with lipopolysaccharide - Inside - periplasmic space - 2 cell membrane - MORE resistant to antibiotics bc of periplasmic space 2. Gram positive - Thick peptidoglycan layer outside of the cell and no other layer - 1 cell membrane - thick PG wall"

Answer 169

"- Inhibited by ATP citrate - Activated by AMP - This makes sense because the cell should turn off glycolysis when it has sufficient energy (high ATP) and turn on glycolysis when it need energy (high AMP) - Citrate is an intermediate of the citric acid cycle so high levels of citrate also imply that the cell is producing sufficient energy."

Answer 170

"1. Glycolysis- Phosphofructokinase-1 2. Fermentation: lactate dehydrogenase 3. Glycogenesis: glycogen synthase 4. Glycogenolysis: glycogen phosphorylase 5. Glucogenesis: fructose-1-6 bisphosphatase 6. Pentose Phosphate Pathway: glucose-6-phosphate dehydrogenase."

Answer 171

C because Schwann cells are the myelin-forming cells in the peripheral nervous system.

Answer 172

"Infectious protein - abnormally folded protein that induces a normally folded version of the protein to also adopt the abnormal structure, which is often deleterious"

Answer 173

- heart, kidneys, skeletal muscles

Answer 174

lysosomes are defined as membrane-bound organelles that contain hydrolytic enzymes activated by a low pH. These enzymes are capable of degrading many kinds of biomolecules.

Answer 175

centrosomes --> microtubules are cellular structures that originate from centrosomes

Answer 176

"1. Transcription is DNA to mRNA - occurs in nucleus 2. Translation - mRNA to proteins - Occurs on a ribosome "

Answer 177

"- has higher phase transition temps | - No double bonds "

Answer 178

- Lipids before being packaged into vesicles and delivered to the plasma membrane or stored in the cell for future use

Answer 179

C is correct. The membrane potential is always measure in terms of the inside of the cell relative to the extracellular fluid.

Answer 180

A because, by definition, nondisjunction is the failure of homologous chromosomes to separate during anaphase I of meiosis or the failure of sister chromosomes to separate during anaphase II of meiosis.

Answer 181

- Asparagine, Glutamine, Tryptophan