Practice Exam IIID (Derived from SS13 Exam IIIA)1. Please choose the True statement:a. The TCA cycle produces 3 molecules of NADH for every acetyl CoA group that enters the cycle.b. The TCA cycle takes place in the cytosol.c. Three-carbon Acetyl Co A condenses with 3C citrate to produce the 6C intermediate, isocitrate.d.The intermediate, fumarate is hydrated through a reaction catalyzed by fumarase to make the intermediate malate.e. All the above are true.f. Only a and d are true.2. Please choose the True statement:a. Two molecules of CO2 are produced by TCA cycle for every acetyl CoA group that enters the cycle.b. The overall rate of catalysis in the TCA cycle is up regulated by high levels of ATP.‐c. The rate of the TCA cycle is influenced primarily through regulation of the enzyme malate dehydrogenase.d. Only a and b are true.3. The alpha-ketoglutarate dehydrogenase enzyme complex requires several cofactors, which include: Coenzyme A, NAD+, and FAD. True False4. Please choose the True statement regarding the use of TCA intermediates in other pathways:a. Oxaloacetate is used to produce nucleotides and some amino acids.b. Succinyl CoA is used in heme synthesis. c. Alpha-ketoglutarate is used to produce amino acids and nucleotides.d. All the above are truee. Only a and c are true.5. Mammals use acetyl CoA to make which of the following:a. Fatty acids, steroids, glucose and citrateb. Fatty acids, glucose, citrate and ketone bodiesc. Fatty acids and citrate onlyd. Fatty acids, citrate, ketone bodies and steroids6. Ubiquinol is formed when ubiquinone accepts electrons from Complex III True False7. If mitochondria were poisoned by addition of cyanide, which of the following would be true:a. Complex III would be poisoned directly. b.Complex II would be poisoned directly. c. Complex I would be poisoned directly. d.Complex IV would be poisoned directly. 8. Please choose the True statement:a. Fatty acids are synthesized in the mitochondrial matrix.b. Citrate is an inhibitor of fatty acid synthesisc. Production of acetyl CoA is the first committed step in fatty acid synthesis.d. There are no true answers here.9. In order, reactions of fatty acid synthesis are: condensation, oxidation, hydration, oxidation. True False10. Phosphorylase a, which is used in glycogen metabolism, is less active than phosphorylase b. True False11. Please choose the *FALSE* statement:a. De novo glycogen synthesis requires the primer, glycogenin.b. Glucose-6 phosphate is released from glycogen branchpoints by the debranching enzyme.c. Glucagon binding to its receptor results in downstream activation of adenylyl cyclase.d. Glucagon is a hormone produced in the pancreas.1Practice Exam IIID (Derived from SS13 Exam IIIA)12. Please choose the true statement:a. Sphingolipids, glycolipids, phospholipids and cholesterol are all used as membrane lipids.b. Cholesterol is used as a synthetic precursor of NAD+c. Cholesterol esters have a Coenzyme A attached to the hydroxyl groupd. Biosynthesis of cholesterol occurs in the mitochondrion.13. Please choose the *FALSE* statement:a. Apolipoprotein B-48 is only made in the small intestine.b. In individuals homozygous for familial hypercholesterolemia, too much LDL remains in the blood.c. LDL receptor synthesis is regulated by cholesterol levels, such that high serum cholesterol results in an increase in LDL receptor synthesis. d. The lipids in LDL particles are mainly comprised of cholesterol and cholesterol esters.14. Please choose the true statement:a. VLDL are formed in the liver and the lipids contained in them are mostly triacylglycerols of dietary origin.b. HMG-CoA reductase catalyzes the first committed step in cholesterol synthesis.c. Glucocorticosteroids are derivatives of arachadonic acid.d. Bile salts are made primarily from fatty acids and are used to emulsify dietary lipids.15. Please choose the true statement:a. Isopentenyl pyrophosphate is made when AMP levels in the cell are high.b In a series of reactions during cholesterol synthesis, 3 Molecules of ATP are used to make isopentenyl pyrophosphate.c. Squalene is a 10-carbon intermediate used in cholesterol synthesis.d. Oxidoreductase cyclizes lanosterol to make farnesyl pyrophosphate.16. Please choose the true statement:a. Acetyl CoA carboxylase catalyzes the committed step in fatty acid beta-oxidation.b. NADPH reduces substrates in the reductive synthetic reactions of fatty acid beta-oxidation.c. NADPH is produced in the non-oxidative pentose phosphate pathway.d. Glutathione is important for reducing peroxides and other reactive oxygen species. 17. Glucose 6-Phosphate dehydrogenase catalyzes the first committed step of the oxidative pentose phosphate pathway. True False18. Rapidly dividing cells that need ribose 5-P for nucleotide synthesis but not NADPH, would use the oxidative pathway only and would not use the non-oxidative pentose pathway. True False19. Deficiency of glucose 6-phosphate dehydrogenase is often sub-clinical and becomes noticeable when a person has hemolytic anemia after oxidative challenge that can be a result of:a. Antibioticsb. Anitmalarialsc. Infectiond. Eating certain foods like fava beanse. All of the above20. During -oxidation of odd-numbered fatty acids, propionyl-CoA is catabolized to succinyl CoA in a series of βreactions that require Vitamin B12. True False2Practice Exam IIID (Derived from SS13 Exam IIIA)21. Isoprene units are used for the construction of all of the following EXCEPT:a. Membrane lipids in archaeab. Sphingomyelin in eukaryotesc. Cholesterold. Lipid anchors for membrane proteins22. Please choose the true statement regarding phosphatidate. Phosphatidate...a. is an intermediate in cholesterol synthesis.b. is an intermediate in sphingolipid synthesis.c. is an intermediate in the synthesis of triacylglycerol.d. All of the above are true.23. Dipalmitoyl phosphatidylcholine can be deficient in preterm infants and lead to respiratory distress. TrueFalse24. Please choose the FALSE answer regarding the response of liver cells to glucagon: Glucagon promotes an …a. increase in the activity of glycogen synthaseb. increase in the activity of glycogen phosphorylase kinasec. increase in the release of free glucosed. increase in the intracellular concentrations of cAMP25. Chylomicrons are produced in the liver and contain more triacylglycerol than cholesterol or cholesterolesters. True False26. Triacylglycerol must be catabolized to monoacylglycerol and two fatty acids to pass
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