Photosynthesis and Cellular Respiration, Exams of Biochemistry

Download Photosynthesis and Cellular Respiration and more Exams Biochemistry in PDF only on Docsity! 1 / 85 BIOC 385 Final Exam Question Set with Correct Answers 1.The Biosphere 2 project, in Tucson, Arizona, was an experiment involving a large sealed terrarium with humans and photosynthetic plants living in balance. Why did the project have to be interrupted after only a few months? a) Levels of CO2 rose to dangerous levels. b) The humans ran out of food. c) The plants stopped producing oxygen. d)The rate of photosynthesis was too high.: a) Levels of CO2 rose to dangerous levels. 2.The is driven directly by photons from the sun in photosynthe- sis light reactions. a) pumping of protons b) synthesis of ATP c) transfer of electrons d) synthesis of glucose: c) transfer of electrons 3.Heme and chlorophyll have similar overall structures. What is 2 / 85 common between the two molecules? a) color b) hydrophobic tail c) polycyclic planar structure d) metal ion found at their center: c) polycyclic planar structure 4.Chlorophyll absorbs light energy efficiently because of the a) metal ion in the center of the molecule. b) ring structure. c )planar structure. d) alternating double and single bonds.: d) alternating double and single bonds. 5.Which of the following is a photosynthetic light harvesting pigment? a) FeS cluster b) NADPH c) plastoquinone d) ²-carotene: d) ²-carotene 6.Approximately how many light-harvesting chromophores are found per photosystem enzyme, such as in PSI or PSII? a) 2 5 / 85 12.In what location of the cell does the Calvin cycle occur? a) chloroplast grana b) thylakoid lumen c) chloroplast stroma d) cytoplasm: c) chloroplast stroma 13.The Calvin cycle requires which species from the light reactions? a) ATP and NADPH b) reducing electrons c) CO2 and ATP d) NADH and FADH2: a) ATP and NADPH 14.The first stage of the three-stage Calvin cycle a) generates CO2. b) uses ATP and NADPH from the light reactions. c) occurs in the plant cell cytoplasm. d) is catalyzed by the enzyme rubisco.: d) is catalyzed by the enzyme rubisco. 15.The formation of one net glyceraldehyde-3-phosphate during the net Calvin cycle reactions requires NADPH and ATP. 6 / 85 a) 3; 3 b) 3; 6 c) 6; 6 d) 6; 9: d) 6; 9 16.What is the name of the enzyme that catalyzes the reaction shown below? a) ribulose bisphosphate carboxylase b) acetyl-CoA carboxylase c) glyceraldehyde-3-phosphate dehydrogenase d) pyruvate carboxylase: a) ribulose bisphosphate carboxylase 17.Transketolase requires the coenzyme a) cobalamin (vitamin B12). b) pyridoxal phosphate. c) tetrahydrofolic acid. d) thiamine pyrophosphate.: d) thiamine pyrophosphate. 18.Which cell type in C4 plants is isolated from O2 exposure as they perform Calvin cycle reactions? a) Hatch-Slack cells b) bundle sheath cells c) guard cells 7 / 85 d) mesophyll cells: b) bundle sheath cells 19.Which of the following is true of the glyoxylate cycle? a) It allows plants to produce glucose from fats and two-carbon molecules like acetate. b) It occurs in plant cells as an alternative to photosynthesis. c) It bypasses all regulated steps of the TCA cycle. d) It results in a net production of ATP and NADH without proceeding through the TCA cycle.: a) It allows plants to produce glucose from fats and two-carbon molecules like acetate. 20.The glyoxylate cycle reaction shown below is catalyzed by which enzyme class? a) lyase b) hydrolase c) transferase d) oxidoreductase: a) lyase 21.Which of the following is classified as a monosaccharide? a) sucrose b) glucose c) lactose 10 / 85 a) more a-1,6 b) fewer a-1,6 c) only a-1,4 d) only a-1,6: c) only a-1,4 29.The glycan group on glycoproteins and glycolipids on the red blood cells all contain the glycan subgroup(s) a) O. b) Gal. c) GalNAc. d) Gal and GalNAc.: a) O. 30.Crystal violet stains Gram-positive bacteria because Gram-positive bacte- ria have a(n) a) outer membrane layer that collapses, trapping the crystal violet molecules. b) thinner peptidoglycan layer that allows the crystal violet molecules to pass through the pores. c) thinner peptidoglycan layer that collapses, trapping the crystal violet mol- ecules. d) thicker peptidoglycan layer that collapses, trapping the crystal violet mol- ecules.: d) thicker peptidoglycan layer that collapses, trapping the 11 / 85 crystal violet molecules. 31.Gram-negative bacteria resist staining with crystal violet because Gram-negative bacteria have a(n) a) outer membrane layer that collapses, releasing the crystal violet molecules. b) thinner peptidoglycan layer that does not retain the crystal violet molecules. c) thinner peptidoglycan layer that collapses, releasing the crystal violet molecules. d) thicker peptidoglycan layer that collapses, releasing the crystal violet molecules.: b) thinner peptidoglycan layer that does not retain the crystal violet molecules. 32.Which enzyme does penicillin target in bacteria? a) B-lactamase b) peptidase c) transpeptidase d) a-galactosidase: c) transpeptidase 33.Which amino acid does penicillin form a complex with on transpeptidase? a) aspartic acid b) lysine 12 / 85 c) alanine d) serine: d) serine 34.Penicillin kills bacteria by inhibiting the biosynthesis of the cell wall. How does penicillin cause the inhibition? a) The transpeptidase of the bacteria binds to methicillin. b) The carbonyl carbon of the B-lactam ring of penicillin binds to transpepti- dase. c) The B-lactam ring in penicillin is hydrolyzed. d) The glycine in transpeptidase binds to penicillin.: b) The carbonyl carbon of the B-lactam ring of penicillin binds to transpeptidase. 35.Both methicillin and penicillin are inactive when exposed to a) transpeptidase. b) transpeptidase and B-lactamase. c) B-lactamase. d) variant transpeptidase.: d) variant transpeptidase. 36.A B-elimination reaction is used in glycan characterization to a) label the antibody arrays. b) fluorescently label glycoproteins. c) cleave the O-linked glycans. 15 / 85 b) 0; 2 c) 2; 0 d) 2; 2: b) 0; 2 43.Which enzyme in the pentose phosphate pathway is regulated to control flux through the pathway? a) glucose-6-phosphate dehydrogenase b) transaldolase c) 6-phosphogluconate dehydrogenase d) ribulose-5-phosphate epimerase: a) glucose-6-phosphate dehydrogenase 44.If the ratio of NADP+ to NADPH were high, the a) net production of ATP would occur. b) pentose phosphate pathway oxidative phase would be activated. c) cellular levels of nucleotides would have to increase from an activated pentose phosphate pathway. d) pentose phosphate pathway would be inhibited.: b) pentose phosphate path- way oxidative phase would be activated. 45.How would individuals with decreased levels of the pentose phosphate enzyme glucose-6-phosphate dehydrogenase respond to oxidative 16 / 85 stress? a) Higher than normal levels of NADPH would accumulate. b)They would not have the ability to regenerate reduced glutathione as rapidly. c) They would rapidly neutralize cellular levels of H2O2 and other reactive oxygen species. d) They would compensate with higher than normal levels of pentose phos- phate pathway activity.: b) They would not have the ability to regenerate reduced glutathione as rapidly. 46.The conversion of pyruvate to phosphoenolpyruvate (PEP) in gluconeoge- nesis a) requires the net input of two equivalents of NADH. b) occurs in two steps and is catalyzed by the enzymes pyruvate carboxylase and phosphoenolpyruvate carboxykinase. c) is a thermodynamically spontaneous reaction that gives rise to a stable product. d) requires lactate as a precursor.: b) occurs in two steps and is catalyzed by the enzymes pyruvate carboxylase and phosphoenolpyruvate carboxykinase. 17 / 85 47.What molecules are missing from boxes in the gluconeogenesis reaction shown below? a) Ser-Pi; Ser-Pi b) H2O; Pi c) ADP; ATP d) ATP; ADP: b) H2O; Pi 48.Which enzyme in the glycolysis pathway catalyzes a reaction that requires two enzymes to reverse in the gluconeogenesis pathway? a) pyruvate kinase b) phosphofructokinase I c) pyruvate dehydrogenase d) glycogen phosphorylase: a) pyruvate kinase 49.Of the four molecules listed below, three of them reciprocally regulate phosphofructokinase 1 (PFK1) and fructose-1,6-bisphosphatase. Which mol- ecule does NOT fit? a) pyruvate b) fructose-2,6-bisphosphate c) citrate d) AMP: a) pyruvate 20 / 85 a) UDP-glucose b) pi c) glucose-1-phosphate d) UDP: d) UDP 57.In the glycogenesis pathway, which enzyme catalyzes the formation of (1,6) linkages? a) debranching enzyme b) glycogen synthase c) glycogen phosphorylase d) branching enzyme: d) branching enzyme 58.In the glycogenesis pathway, the role of the glucose-6-phosphate isomer- ization reaction is to a) create a more stable intermediate for the subsequent reaction. b) decrease the concentration of glucose-6-phosphate, thereby driving the pathway forward. c) ensure that the charged molecule stays in the cell. d) prepare the anomeric carbon for nucleophilic attack.: d) prepare the anomeric carbon for nucleophilic attack. 59.In the breakdown of glycogen, the debranching enzyme catalyzes 21 / 85 the formation of a) glucose-1-phosphate. b) glucose. c) a(1,6) branched glycogen. d) glucose-6-phosphate.: b) glucose. 60.The debranching enzyme does NOT catalyze the a) formation of a(1,6) linkages. b) cleavage of a(1,6) linkages. c) formation of a(1,4) linkages. d) cleavage of a(1,4) linkages.: a) formation of a(1,6) linkages. 61.What class of biomolecule is glycogenin? a) hormone b) carbohydrate c) enzyme d) lipid: c) enzyme 62.Why is it important that muscle cells are unresponsive to glucagon? a) Muscle cells store glycogen for its own energy needs and not the needs of other tissues. b) The muscles do not store glycogen. 22 / 85 c) The muscles release glucose to other tissues in need. d) Muscle cells respond to insulin instead.: a) Muscle cells store glycogen for its own energy needs and not the needs of other tissues. 63.Predict the structure of a fatty acid that is trans 16:1 (9).: 64.Predict the fatty acid with the lowest melting point. a) trans 14:1 (7) b )cis 14:2 (7,9) c) trans 14:2 (7,9) d) cis 14:3 (7,9,11): d) cis 14:3 (7,9,11) 65.One disadvantage of using partial hydrogenation in the food industry is that a) the shelf life of the oils is not as long. b) trans fats are formed during the process. c) the oils tend to become rancid and have foul odors. d) the oils cost more than animal fats.: b) trans fats are formed during the process. 66.Predict the essential -6 fatty acid. a) trans 18:2 (9,12) b) cis 18:2 (9,12) 25 / 85 c) 3 d) 4: a) 1 73.The outer layer of the plasma membrane of human erythrocytes contains mostly lipids. a) phosphatidylinositol b) phosphatidylserine c) phosphatidylcholine d) phosphatidylethanolamine: c) phosphatidylcholine 74.The inner layer of the plasma membrane of human erythrocytes contains mostly lipids. a) phosphatidylserine b) ganglioside c) phosphatidylcholine d) sphingomyelin: a) phosphatidylserine 75.Compared with other areas of the membrane, lipid rafts contain more a) sphingolipids. b) phosphatidylcholine. c) phosphatidylinositol. d) gangliosides.: a) sphingolipids. 26 / 85 76.The addition of phosphocholine to ceramides generates a) glycerophospholipids. b) gangliosides. c) cerebrosides. d) sphingomyelin.: d) sphingomyelin. 77.Which of the following membranes would have the greatest fluidity based on the following percentage of cholesterol in the membrane? a) 10% b) 25% c) 30% d) 40%: a) 10% 78.Which of the following molecules aid in the absorption of dietary lipids? a) prostaglandin b) cortisol c) glycocholate d) aldosterone: c) glycocholate 79.Cortisol is a glucocorticoid that regulates a) blood pressure. b) ion transport in the kidneys. 27 / 85 c) testosterone. d) liver metabolism.: d) liver metabolism. 80.A patient is having problems regulating blood pressure and has poor kidney function. Which steroid could be responsible for this? a) progesterone b) cortisol c) aldosterone d) estradiol: c) aldosterone 81.Which steroid hormone is synthesized in the corpus luteum? a) cortisol b) progesterone c) testosterone d) estradiol: b) progesterone 82.7-Dehydrocholesterol is converted to cholecalciferol (Vitamin D3) by a) P450C1 hydroxylase. b) P450C12 hydroxylase. c) P450C25 hydroxylase. d) ultraviolet light.: d) ultraviolet light. 83.Vitamin D3 is converted to 25-hydroxyvitamin D3 in the cells. 30 / 85 a) acyl-CoA dehydrogenase b) acetyl-CoA carboxylase c) fatty acyl-CoA synthetase d) carnitine acyltransferase I: d) carnitine acyltransferase I 91.Which molecule is used to transport fatty-acyl groups into the mitochon- dria? a) CoA-SH b) ATP c) biotin d) carnitine: d) carnitine 92.What enzyme class catalyzes the following reaction? (Note that there may be some missing reactants and products.) a) lyase b) hydrolase c) transferase d) dehydrogenase: d) dehydrogenase 93.How many more passes through B-oxidation does the saturated fat stearic acid (18:0) require, compared with the monounsaturated fat oleic acid (18:1)? 31 / 85 a) 0 b) 1 c) 2 d) 17: a) 0 94.The B-oxidation of mono- and polyunsaturated fatty acids a) requires an extra cycle through the pathway. b) involves the reduction of the double bonds and then the continuation of B-oxidation. c) yields succinyl-CoA. d) involves isomerization and in some cases reduction of the double bonds before the continuation of B-oxidation.: d) involves isomerization and in some cases reduction of the double bonds before the continuation of B-oxidation. 95.How do we deal with the double bonds during the degradation of unsatu- rated fatty acids? a) Convert the three-carbon propionyl-CoA to succinyl-CoA and feed it into the TCA cycle. b) Converge them with the TCA cycle to produce acetyl-CoAs. c) Isomerize the position of the double bonds to converge them with 32 / 85 the B-oxidation pathway. d) Reduce them to single bonds and feed the saturated fatty acid into the B-oxidation pathway.: c) Isomerize the position of the double bonds to converge them with the B-oxidation pathway. 96.What extra enzyme types are often required in the degradation of polyun- saturated fats by the B-oxidation pathway? a) reductase and isomerase b) hydrolase and isomerase c) oxidoreductase and reductase d) synthase and isomerase: a) reductase and isomerase 97.Which is found in the ketone body pathway? a) succinyl-CoA. b) propionyl-CoA. c) dihydroxyacetone phosphate. d) hydroxybutyrate.: d) hydroxybutyrate. 98.A difference between FA synthesis and -oxidation is that FA synthesis , whereas B-oxidation . a) reactions use ATP; reactions directly yield ATP b) occurs in the mitochondria; takes place in the cytoplasm 35 / 85 whereas the ACP does not. d) The ACP delivers two carbon fragments one at a time, whereas the KS domain passes them on to the fatty acid.: a) The ACP carries the growing fatty acid chain more than the KS domain. 104. The introduction of 14CO2 into a cell actively synthesizing fatty acids results in 14C labeled a) malonyl-CoA. b) acetyl-CoA. c) acyl-CoA. d) palmitate.: a) malonyl-CoA. 105. Membrane phospholipids are synthesized in which cellular location? a) cytoplasm b) mitochondrial intermembrane space c) mitochondrial matrix d) smooth endoplasmic reticulum: d) smooth endoplasmic reticulum 106. The acetyl-CoA for fatty acid synthesis comes from the a) breakdown of fats. b) TCA cycle. c) mitochondria via the citrate shuttle. 36 / 85 d) breakdown of cytoplasmic pyruvate.: c) mitochondria via the citrate shuttle. 107. Which of the following causes inhibition of fatty acid synthesis? a) increased insulin b) increased AMP-activated protein kinase (AMPK) c) decreased cytoplasmic acyl-CoA d) increased cytoplasmic acetyl-CoA: b) increased AMP-activated protein kinase (AMPK) 108. What enzyme is activated by HDL to release cholesterol from the cell membranes of peripheral tissues? a) phosphatidylcholine esterase b) HDL apolipase c) cholesterol esterase d) lecithin-cholesterol acyltransferase: d) lecithin-cholesterol acyltransferase 109. Which lipid is thought to give rise to the plaques that can clog arteries? a) HDL b) LDL 37 / 85 c) VLDL d) chylomicrons: b) LDL 110. The 10 amino acids that animals need to take in through their diet are called the amino acids. a) common b) essential c) optional d) degradation: b) essential 111. What are the four key enzymes in nitrogen fixation and assimilation in plants and bacteria? a) nitrogenase synthetase, glutamine complex, glutamate synthase, glutamate dehydrogenase b) nitrogenase complex, glutamine synthetase, glutamate synthase, glutamate dehydrogenase c) glutamine synthetase, glutamate synthase, glutamate dehydrogenase, glu- tamate oxidase d) nitrogenase complex, glutamine synthetase, glycine synthase, glutamine dehydrogenase: b) nitrogenase complex, glutamine synthetase, glutamate syn- thase, glutamate dehydrogenase 40 / 85 b) cleaves chymotrypsinogen to form chymotrypsin. c) generates peptides and amino acids. d) neutralizes the pH of the duodenum to a pH of 7.: a) cleaves trypsinogen to form trypsin. 119. It is important that proteolytic enzymes in the lysosome are optimized to work at low pH because low pH a) enhances protein denaturing. b) deactivates cysteine proteases. c) makes it easier for ATP to be converted to ADP + Pi. d) enhances the degradation of ubiquitinated proteins.: a) enhances protein denaturing. 120. What nitrogen source is used to produce carbamoyl phosphate? a) alanine b) urea c) ammonia d) glutamine: c) ammonia 121. When amino acids from dietary proteins enter a cell, how are they able to enter the urea cycle? a) through conversion to glutamine 41 / 85 b) through conversion to aspartate c) by degrading down to ammonia d) by getting phosphorylated: b) through conversion to aspartate 122. The urea cycle's function is to the body of an organism. a) remove excess sugar from b) remove excess water-soluble vitamins from c) remove excess nitrogen from d) add additional nitrogen to: c) remove excess nitrogen from 123. Which of the following is the net reaction of the urea cycle? a) Urea + Fumerate + 2 ADP + 2Pi + AMP + PPi NH+ + HCO3- + aspartate + 3ATP b) NH+ + HCO3 + aspartate + 3ATP urea + fumerate + 2 ADP + 2Pi + AMP + PPi c) NH+ + HCO3 + fumerate + 3ATP urea + aspartate + 2 ADP + 2Pi + AMP + PPi d) NH+ + HCO3 + aspartate + 2 ADP + 2Pi + AMP + PPi urea + fumerate + 3ATP: b) NH+ + HCO3 + aspartate + 3ATP urea + fumerate + 2 ADP + 2Pi + AMP 42 / 85 + PPi 124. Using the figure below, determine which of the following is NOT a final product from group 1 amino acid degradation. a) glycine b) pyruvate c) acetoacetyl-CoA d) acetyl-CoA: a) glycine 125. If no NAD+ was available, the group 2 amino acid degradation pathway would experience a a) buildup of urea. b) buildup of glutamate. c) depletion of proline. d) depletion of histidine.: b) buildup of glutamate. 126. Alkaptonuria is a disease coming from a deficiency in which pathway? a) group 1 b) group 2 c) group 3 d) urea: c) group 3 45 / 85 d) phosphopentomutase; phosphoriboxyl transferase; kinase; PRPP syn- thetase; kinase: c) phosphopentomutase; PRPP synthetase; phosphoriboxyl trans- ferase; kinase; kinase 133. In purines, nitrogen atoms and carbon atoms originate from glycine. a) 0; 2 b) 1; 1 c) 2; 1 d) 1; 2: d) 1; 2 134. The nitrogen atoms of a purine originate from all of the following amino acids EXCEPT a) glycine. 46 / 85 b) aspartate. c) cysteine. d) glutamine.: c) cysteine. 135. If HCO3 that is radioactively labeled with 13C is available, which carbon atom in the molecule below would ultimately be expected to be radioactive? a) A b) B c) C d) D: c) C 136. A product of the first stage of purine biosynthesis is , whereas is a by-product of the second stage. a) fumarate; glycine b) glutamine; glutamate c) fumarate; glutamate d) glutamate; fumarate: d) glutamate; fumarate 137. The transformation of ribose-5-phosphate to AIR in the first stage of purine biosynthesis in E. coli consumes the equivalent of 5 ATP. The 47 / 85 second stage consumes a) an additional 5 ATP. b) more than 5 ATP. c) less than 5 ATP and generates 1 ATP. d) less than 5 ATP.: d) less than 5 ATP. 138. A mutation in the gene encoding which of the following enzymes would affect the synthesis of both AMP and GMP? a) adenylosuccinate synthetase b) PRPP synthetase c) IMP dehydrogenase d) GMP synthase: b) PRPP synthetase 139. Which of the following is an intermediate in the conversion of AMP to uric acid but NOT an intermediate in the conversion of GMP to uric acid? a) A b) B c) C d) D: b) B 140. Nonprimate mammals convert uric acid to allantoin. This reaction, cat- alyzed by urate oxidase, also generates which of the 50 / 85 143. Aspartate contains four carbons. If all are radioactively labeled, how many carbons of UMP will be radioactively labeled? a) 0 b) 2 c) 3 d) 4: c) 3 144. How many of the nitrogens in orotidine-5'-monophosphate arise from glutamine? a) 0 b) 1 c) 2 d) 3: b) 1 145. Consider a cell that is provided aspartate in which all carbons are radioac- tively labeled. Compounds in the cell are analyzed after the biosynthesis and subsequent breakdown of pyrimidines. Which of the following compounds would display no radioactivity signal during the analysis? a) B-alanine b) glutamine 51 / 85 c) B-aminoisobutyrate d) dihydrouracil: b) glutamine 146. Complete the following pathway of the degradation of UMP.UMP Uridine Dihydrouracil NH4+ + HCO3- + B-alanine a) uracil; N-carbamoyl-B-aminoisobutyrate b) N-carbamoyl-uracil; B-alanine CoA c) uracil; N-carbamoyl-B-alanine d )orotate; uracil: c) uracil; N-carbamoyl-B-alanine 147. Which answer INCORRECTLY pairs a substrate and subsequent product of dihydropyrimidine dehydrogenase? a) thymine; dihydrothymine b) uracil; dihydrouracil c) adenine; dihydroadenine d )5-fluorouracil; fluorodihydrouracil: c) adenine; dihydroadenine 148. To determine the role of glutaredoxin in the generation of deoxyribonu- cleotides by ribonucleotide reductase, which organisms would be the best to study? a) bony fish 52 / 85 b) bacteria c) humans d) amphibians: b) bacteria 149. To purify glutathione reductase to carry out a kinetics analysis, which organism would be the best source of the enzyme? a) cod fish b) chimpanzee c) E. coli d) turtle: c) E. coli 150. The biosynthesis of deoxynucleosides is important, yet different organ- isms require different sets of enzymes to carry it out. If 100 different species were analyzed, which enzyme is most likely to be found in all of them? a) ribonucleotide reductase b) thioredoxin c) glutaredoxin d) glutathione reductase: a) ribonucleotide reductase 151. The importance of stable free radicals in the mechanism of E. coli ribonu- cleotide reductase was identified in the early 1970s. The existence of 55 / 85 b) glucagon c) somatostatin d) LpL: b) glucagon 157. The expected outcome in adipose tissue after exposure to glucagon would be an increased a) glucose uptake through GLUT4. b) glycerol synthesis. c) fatty acid uptake from lipoprotein particles. d) triacylglycerol hydrolysis.: d) triacylglycerol hydrolysis. 158. Which of the following would show increased activity levels in a liver cell after exposure to insulin? a) phosphorylase kinase b) phosphofructokinase-1 c) glycogen phosphorylase d) fructose-1,6-bisphosphatase: b) phosphofructokinase-1 159. Analysis of various cell types after exposure to insulin would show an increase in triacylglycerol synthesis in which of the following? a) brain b) skeletal muscle 56 / 85 c) liver d) pancreas: c) liver 160. Which of the following is NOT one of the three peroxisome prolifera- tor-activated receptor nuclear receptor proteins that function in metabolic homeostasis? a) PPAR-a b) PPAR-B c) PPAR-o d )PPAR-y: b) PPAR-B 161. PPARs have a variety of functions in lipid metabolism that include all EXCEPT a) regulation of lipid transport. b) mobilization of fatty acid oxidation. c) mobilization of lipid synthesis. d) decreasing insulin sensitivity.: d) decreasing insulin sensitivity. 162. Enzyme activities after PPAR signaling were monitored in both liver and skeletal muscle. When compared with activities before PPAR signaling, which of the following would have been found to increase in liver but NOT in skeletal muscle? 57 / 85 a) acyl CoA dehydrogenase b) enoyl-CoA hydratase c) transketolase d) acetyl-CoA acetyltransferase: c) transketolase 163. The graph below shows the relative changes in concentration of glucose, fatty acids, and ketone bodies during 40 days of starvation. Choose the answer that correctly labels the data on the graph. a) X = fatty acids; Y = glucose; Z = ketone bodies b) X = glucose; Y = fatty acids; Z = ketone bodies c) X = ketone bodies; Y = glucose; Z = fatty acids d) X = ketone bodies; Y = fatty acids; Z = glucose: c) X = ketone bodies; Y = glucose; Z = fatty acids 164. Leptin is a a) mutated form of insulin. b) hormone receptor expressed in adipocytes. c) adipocyte peptide hormone. d) recessive gene that causes obesity.: c) adipocyte peptide hormone. 165. Which of the following neurons is a second-order neuron and therefore does NOT respond directly to leptin? 60 / 85 171. Thiazolidinedione activates PPARy in adipose tissue. This results in the upregulation of a) TNF-a. b) plasminogen activator inhibitor 1. c) interleukin-6. d) phosphoenolpyruvate carboxykinase.: d) phosphoenolpyruvate carboxyki- nase. 172. During intense exercise, muscle ATP stores will be depleted in about a) 3 minutes. b) 5 minutes. c) 30 seconds. d) 3 seconds.: d) 3 seconds. 173. Fully active AMPK results in an increase in all pathways listed EXCEPT a) glycolytic flux. b) fatty acid oxidation. c) oxidative phosphorylation. d) fatty acid synthesis.: d) fatty acid synthesis. 61 / 85 174. Semiconservative, as it relates to DNA replication, can be defined as when the original duplex DNA template a) remains intact to make a new DNA duplex. b) is broken into fragments. c) is separated into single strands before replications. d) can only be replicated once.: c) is separated into single strands before replica- tions. 175. A replication fork is necessary because it allows a) for DNA replication to start on a single strand. b) for DNA replication to start on the double strand. c) DNA to break into half to start replication. d) DNA to unwind completely to start replication.: a) for DNA replication to start on a single strand. 176. Bidirectional replication is defined as replication a) with one replication fork. b) with two replication forks. c) that unwinds the DNA completely to replicate. d) that replicates the DNA in a given direction.: b) with two replication forks. 177. The complete complex that contains the enzymes and proteins 62 / 85 required to replicate DNA is called the a) primase. b) polymerase. c) replisome. d) DNA gyrase.: c) replisome. 178. The main function of the primosome is to a) synthesize primers for leading strand synthesis. b) synthesize primers for lagging strand synthesis. c) bind to single-stranded DNA to prevent reannealing. d) synthesize new DNA on leading and lagging strand.: b) synthesize primers for lagging strand synthesis. 179. The two key elements of the oriC include a) three 13-bp repeats and four 9-bp repeats with enriched G-C base pairs. b) three 13-bp repeats and four 9-bp repeats with enriched A-T pairs. c) 20 subunits of A-T pairs. d) the RNA primer.: b) three 13-bp repeats and four 9-bp repeats with enriched A-T pairs. 180. The role of CDK in DNA synthesis is to a) remove the histones. 65 / 85 permanently becomes a) phosphorylated. b) methylated. c) protonated. d) ionized.: b) methylated. 188. What DNA damage can the MGMT enzyme repair? a) phosphorylated adenine b) methylated guanine c) pyrimidine dimers d) mismatched bases: b) methylated guanine 189. Homologous recombination repairs what kind of DNA damage? a) single-strand break b) double-strand break c) mismatched pairs d) pyrimidine dimers: b) double-strand break 190. Lysogeny by bacteriophages causes what result to the host DNA? a) integration of virus DNA into host DNA b) production of new bacteriophage particles c) cell death 66 / 85 d) formation of Holliday junctions: a) integration of virus DNA into host DNA 191. An advantage of viral DNA using LTR to produce a four-nucleotide over- hang on the 32 end is to a) start replication. b) help with alignment of the viral DNA to the host DNA. c) start a base mismatch repair sequence. d) help with cell meiosis.: b) help with alignment of the viral DNA to the host DNA. 192. Which class of RNA molecule is typically the shortest in length? a) transfer RNA b) messenger RNA c) small nuclear RNA d) micro RNA: d) micro RNA 193. Which of the following is a coding RNA molecule? a) short interfering RNA. b) TERC RNA. c) small nucleolar RNA. d) messenger RNA.: d) messenger RNA. 67 / 85 194. Of the following protein synthesizing RNA molecules, which codes for a protein? a) tRNA b) siRNA c) mRNA d) rRNA: c) mRNA 195. Which RNA molecule does NOT bind to the ribosome? a) tRNA b) rRNA c) mRNA d) snRNA: d) snRNA 196. The most significant influence on why mRNA is processed differently in prokaryotes than eukaryotes is the fact that a) eukaryotes separate transcription and translation with a nucleus. b) prokaryotes are often polycistronic. c) eukaryotes are multicellular organisms. d) prokaryotes do not add a poly(A) tail.: a) eukaryotes separate transcription and translation with a nucleus. 197. A 7-methylguanylate cap and poly(A) tail is added to mRNA to 70 / 85 substrate 204. Which is true of ribozymes? a) They have conserved primary sequences. b) They are not true catalysts. c) They are transcription factors. d) They have conserved secondary and tertiary structures.: d) They have con- served secondary and tertiary structures. 205. A common RNA base modification is a) methylation. b) amination. c) carboxylation. d) hydroxylation.: a) methylation. 206. Which is central to the addition of the 7-methylguanosine cap to mRNA? a) RNA polymerase 1 b) guanine-N7 methyltransferase c) GMP d) snoRNA: b) guanine-N7 methyltransferase 207. Which type of RNA facilitates RNA interference by resulting in 71 / 85 degraded mRNA? a) snoRNA b) siRNA c) miRNA d) rRNA: b) siRNA 208. Which RNA molecule is expressed in the genome to regulate gene ex- pression? a) RNAi b) snoRNA c) miRNA d) siRNA: c) miRNA 209. The adaptor molecule in translation is a) aminoacyl-tRNA synthetase. b) mRNA. c) rRNA. d) tRNA.: d) tRNA. 210. tRNA must be before binding to the ribosome to allow for translation to occur. a) charged with a codon 72 / 85 b) charged with an anticodon c) charged with an amino acid d) bound by ATP: c) charged with an amino acid 211. Consider an in vitro experiment in which all components needed for protein synthesis are present. If tRNAs charged with radioactively labeled amino acids are added, over time the radioactivity would be located in which of the following components? a) mRNA b) aminoacyl tRNA synthetase c) nascent protein d) codons: c) nascent protein 212. Which of the following mRNA codons would NOT be recognized by a tRNA that is charged with an amino acid? a) CAA b) GUU c) CUC d) UAA: d) UAA 213. Where would an amino acid be attached to the tRNA below? 75 / 85 hydrolyzes GTP during the step of translation. a) initiation b) elongation c) translocation d) termination: d) termination 220. After the initiation complex is complete, what occurs next in the process of translation? a) peptide bond formation b) EF-G•GTP binding c) EF-Tu•GTP AA-tRNAAA binding d) RF2 binding: c) EF-Tu•GTP AA-tRNAAA binding 221. How many GTP are hydrolyzed during a single round of translation elon- gation in a eukaryote? a) 0 b) 1 c) 2 d) 6: c) 2 222. Which of the following is NOT a component that is released from the ribosome on translation termination? 76 / 85 a) RF2 b) nascent polypeptide c) tRNA d) Met-tRNAfMet: d) Met-tRNAfMet 223. Which antibiotic functions by inhibiting DNA gyrase? a) vancomycin b) coumermycin c) aminoglycosides d) clindamycin: b) coumermycin 224. The antibiotics streptomycin, tetracycline, and chloramphenicol all inter- fere with a) cell membrane formation. b) protein synthesis. c) nucleic acid synthesis. d) cell wall formation.: b) protein synthesis. 225. In the ER, prenylation can occur. Prenylation is the attachment of an isoprenoid group to a residue via a(n) . a) lysine; amide 77 / 85 b) cysteine; thioester c) threonine; ester d) serine; ester: b) cysteine; thioester 226. A protein is targeted to the plasma membrane. Its final functional location is as a subunit of a transmembrane protein that interacts with the central subdomain of the membrane. Analysis of this protein would most likely show modification with a a) myristoylate. b) palmitoylate. c) isoprenoid. d) phosphate.: b) palmitoylate. 227. Which sequence is MOST likely to contain an O-linked oligosaccharide in the ER? (The ... represents additional amino acids N- terminal or C-terminal to those shown.) a) ...Phe-Leu-Cys-Gly-Leu-Ile... b) ...Gly-Leu-Phe-Ala-Ile-Gly... c) ...Tyr-Leu-Ala-Ile-Gly-Phe... d) ...Ala-Thr-Leu-Phe-Ser-Gly...: d) ...Ala-Thr-Leu-Phe-Ser-Gly... 228. Which of the following sequences is most likely a nuclear 80 / 85 b) a-helix; a-helix c) B-helix; B-helix d) B-helix; a-helix: b) a-helix; a-helix 234. In a leucine zipper, the leucine resides are found every seventh amino residue. This forces the supersecondary structure to be a(n) a) a-helix. b) B-sheet. c) coiled-coil. d) hairpin turn.: c) coiled-coil. 235. Which of the following is NOT a common mechanism for modifying transcription factor activity? a) allosteric activation b) covalent modification c) ionic modification d) positive modulation: c) ionic modification 236. The figure below shows autoregulation and will . a) positive; reach a steady state b) positive; be zero in the absence of an activator 81 / 85 c) negative; reach a steady state d) negative; be zero in the absence of an activator: c) negative; reach a steady state 237. Which of the following best describes when a pattern of gene expression is altered without change in the DNA sequence? a) epigenetic states b) negative autoregulation c) positive autoregulation d) meiosis: a) epigenetic states 238. When IPTG is added to a cell, what is the predicted outcome? a) Protein synthesis stops. b) Protein overproduction occurs. c) The DNA sequence coding for a given protein is altered. d) An epigenetic state occurs.: b) Protein overproduction occurs. 239. When running an assay for luciferase, what reporter gene has been inserted into the plasmid? a) lacZ b) luc c) cat 82 / 85 d) gfp: b) luc 240. When Cro is bound to OR3, the a) lysogenic pathway is favored. b) lytic pathway is favored. c) Cro protein inhibits the PR promoter. d) CI protein activates the PRM promoter.: b) lytic pathway is favored. 241. When trp operon is attenuated, what does that mean for the trp operon? a) inhibition of transcriptional initiation by RNA polymerase b) disruption of transcriptional elongation by RNA polymerase c) initiation by RNA polymerase d) enhancement of transcriptional elongation by RNA polymerase: b) disrup- tion of transcriptional elongation by RNA polymerase 242. When the lysine side chain in a histone is acetylated, the amino group is now a) positively charged. b) neutral. c) negatively charged. d) removed.: b) neutral.