past paper
Microsoft Word - bis103 final s2016 verA .docx 1 BIS103-‐001 Spring 2016 Final Version A Write your name on your scantron and bubble in your student ID number AND test identifier (Version A, B, or C) -‐ 2 points will be subtracted if either piece of info is omitted T = 25 ºC (298 K) ∆G°’ = –nF∆E°’ T = 37 ºC (310 K) E= E°’+ (0.026V/n)ln [electron acceptor]/[electron donor] R = 8.315 J / mol K F= 96.5 kJ/V•mol Please choose the single best answer for each question and fill in the corresponding bubble on your scantron. You will only hand in the scantron, so please make sure you fill in the bubble for your answer thoroughly. All questions are worth 2 points. 2 1) Which of the following enzymes involving nitrogen assimilation is not present in mammals? a. Glutamine synthetase b. Nitrite reductase c. Nitrate reductase d. Glutamate synthase e. 2 or more of the above 2) What is a ketogenic amino acid? a. An amino acid that assists in preventing ketosis, or the over accumulation of ketone bodies b. An amino acid that is derived from ketone bodies c. An amino acid that can be a precursor to ketone bodies d. An amino acid that can bind to ketone bodies e. None of the above 3) What is an incorrect statement of the purpose of amino acid catabolism? a. To provide energy sources, particularly during starvation b. To provide carbon skeletons for use in the CAC, and subsequently gluconeogenesis c. To breakdown amino acids into compounds such as fumarate, acetyl-‐CoA or acetoacetate d. To generate ATP from the oxidation of carbon skeletons into CO2 and H20 e. All of the above describes the purpose of amino acid catabolism 4) Which of the below describes a difference between aminotransferases and oxidative deamination? a. Aminotransferases release free ammonia; oxidative deamination replace amino groups with oxygen b. Aminotransferases transfer an amino group from an amino acid to alpha-‐ketoglutarate, forming the alpha keto acid and glutamate; oxidative deamination releases a free ammonia and forms an oxidized product c. Oxidative deamination release free ammonia and require ATP d. Aminotransferases transfer an amino group from an amino acid to glutamate, forming the alpha keto acid and alpha-‐ketoglutarate; oxidative deamination releases a free ammonia and oxidizes glutamate into alpha-‐ketoglutarate e. Aminotransferases transfer amino groups from one amino acid to another, thereby giving the cell flexibility in ketogenic vs glucogenic pathways. Oxidative deamination oxidizes amino acids for use in gluconeogenesis. 5) Carbamoyl phosphate is involved in which of the following processes? a. Citric Acid Cycle b. Pentose Phosphate Pathway c. Glycogen breakdown d. Calvin cycle e. Urea cycle 3 6) How is ammonia transported out of the mitochondria? a. Incorporated into carbamoyl phosphate, which is transported to the cytosol then dephosphorylated into citrulline b. Incorporated into ornithine, which is then transported to the cytosol c. It is not transported out of the mitochondria d. Incorporated into carbamoyl phosphate, which reacts with ornithine to form citrulline, which is then transported to the cytosol e. Concentrated into urea, which is then transported to the cytosol 7) What is the enzyme that catalyzes the following reaction: a. glutamine synthase b. glutamate kinase c. glutamate phosphatase d. alanine kinase e. glutamate dehydrogenase 8) Which process takes place in the cytosol? a. Citric acid cycle b. Beta-‐oxidation of fatty acids c. Fatty acid synthesis d. Ketone body formation e. Oxidative phosphorylation 9) Where is glycogen stored? a. Liver b. Skeletal muscle c. Adipose tissue d. Heart e. a and b 10) Phosphocreatine a. Provides sustained energy during heavy activity b. Fuels glycolysis during quick bursts of heavy activity c. Maintains homeostasis by always providing low levels of ATP during rest d. Provides small amounts of ATP during bursts of heavy activity e. Is a phosphorylated amino acid important in muscle proteins 4 11) 3-‐phosphoglycerate is a precursor for which of the following amino acids: a. glutamate, glutamine, and proline b. serine, glycine, and cysteine c. aspartate, asparagine, and alanine d. arginine, proline, and glutamine e. a and d 12) Which of the following metabolic effects do not occur due to insulin signaling? a. increase in fatty acid synthesis in the liver b. increase in gluconeogenesis in the liver c. increase glucose uptake in the muscle d. increase glycogen synthesis in the liver e. All of the above will be triggered by insulin 13) Which of the following is NOT a method of regulating metabolic pathways/enzyme activity within a cell? a. Using covalent modification and allosteric regulation on the same enzyme b. Having more than one type of allosteric regulator work on the same enzyme c. Controlling the rate of synthesis of the enzyme at the level of transcription d. Having different enzymes catalyzing the same reaction in a pathway e. All of the above are possible ways of regulating metabolic pathways/enzyme activity 14) What is the enzyme class that converts dihydroxyacetone phosphate and glyceraldehyde-‐3-‐ phosphate? a. hydrolase b. isomerase c. kinase d. hydratase e. dehydrogenase 15) Which of the following statements is true for the synthesis of nucleotides? a. Nucleotide synthesis only occurs through a de novo pathway where the ring structures are built in steps b. Several atoms of a purine ring come from atoms originally in aspartate, glycine, and glutamine c. The starting molecule for both pyrimidine and purine synthesis is aspartate d. 5-‐Phosphoribosyl 1-‐pyrophosphate (PRPP) is used in pyrimidine synthesis but not purine synthesis e. all of the statements are true 5 16) What is the significance of this molecule below? a. it is alpha ketoglutarate, an important metabolite of the CAC and the amino group acceptor in aminotransferase reactions b. it is the volatile ketone body which gets exhaled during ketogenesis c. it is urea, the excretory nitrogen product for many terrestrial vertebrates d. it is the cofactor tetrahydrofolate, which mediates 1 carbon transfer reactions e. it is one of the twenty common amino acids 17) What role do chylomicrons play in lipid digestion? a. Chylomicrons transport triacylglycerols, cholesterol and apolipoproteins from the digestive tract to the tissues. b. Chylomicrons transport triacylglycerols, cholesterol and apolipoproteins from adipose tissue to the brain for catabolism. c. Chylomicrons transport bile salts from the gallbladder to the small intestine for emulsification of dietary fats. d. Chylomicrons break down lipids into smaller byproducts for transport throughout the lymphatic system and bloodstream to the tissues e. one or more of the above 18) Which of the following describes the activation step which occurs before fatty acid breakdown? Palmitate = C16:0, Stearate = C18:0 a. Palmitate + ATP + CoA à palmitoyl-‐CoA + AMP + 2 Pi b. Palmitate + ATP + CoA à palmitoyl-‐CoA + ADP + Pi c. Palmitate + ATP + CoA à Stearoyl-‐CoA + ADP + Pi d. Palmitate + ATP + Acetyl-‐CoA à Steroyl-‐CoA + Acetate + ADP + Pi e. Palmitate + ATP + Acetyl-‐CoA à palmitoyl-‐CoA + Acetate +AMP +2Pi 19) How may the liver supply substrates for gluconeogenesis within a liver cell? a. Through break down of glycogen to produce glucose. b. Through conversion of alanine to pyruvate. c. By converting acetoacetate to alanine. d. By increasing production of lactate in the liver to convert to pyruvate. e. All of the above 20) What metabolite is found in both the Citric acid cycle and the Urea cycle? a. Ornithine b. Oxaloacetate c. Arginino-‐succinate d. Fumarate e. Malate 6 21) What is the correct order of the CAC enzymes? a. citrate synthase, isocitrate dehydrogenase, malate dehydrogenase, succinyl-‐CoA synthetase, fumarase, succinate dehydrogenase, aconitase, α-‐ketoglutarate dehydrogenase b. malate dehydrogenase, citrate synthase, aconitase, isocitrate dehydrogenase, α-‐ ketoglutarate dehydrogenase, succinyl-‐CoA synthetase, fumarase, succinate dehydrogenase c. malate dehydrogenase, citrate synthase, aconitase, α-‐ketoglutarate dehydrogenase, isocitrate dehydrogenase, succinyl-‐CoA synthetase, succinate dehydrogenase, fumarase d. citrate synthase, aconitase, isocitrate dehydrogenase, α-‐ketoglutarate dehydrogenase, succinyl-‐CoA synthetase, succinate dehydrogenase, fumarase, malate dehydrogenase e. citrate synthase, aconitase, α-‐ketoglutarate dehydrogenase, isocitrate dehydrogenase, succinate dehydrogenase, succinyl-‐CoA synthetase, fumarase, malate dehydrogenase 22) What is the driving force for ATP biosynthesis in oxidative phosphorylation? a. The speed of glycolysis b. The activation of pyruvate dehydrogenase by NADH c. The pH difference across the inner mitochondrial membrane d. The mobility of subunits of ATP synthase e. The malate-‐aspartate shuttle 23) What is an incorrect statement about lipid β -‐oxidation? a. Acyl-‐CoA dehydrogenase creates a double bond between C2 and C3 of the substrate in the first of four repetitive steps b. The first three reactions of the four reaction process create a less stable C-‐-‐C bond to allow for the cleavage reaction by thiolase in the last step c. β -‐oxidation generates NADH and FADH2 d. β -‐oxidation requires ATP for forming