Medical Biochemistry Examination II November 9, 2002 Kresge Auditorium Please follow these directions:

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1 Medical Biochemistry Examination II November 9, 2002 Kresge Auditorium Please follow these directions: 1. Do not begin the exam until all students have received a copy of the exam. You will be instructed as to when to break the seal. 2. The exam consists of 88 questions on 19 pages, with this title page considered page 1. There are 150 points on this exam. The point value for each question is indicated by the question. For multiple answer questions without a defined number of answers 0.25 points will be deducted for each incorrect answer, although the lowest point value assigned for a question is 0. No such multiple answer question will have more than 4 correct answers. If a question has a defined number of answers (and this may be more than 4), there is no penalty for guessing. 3. Place your ID number on every page of the exam booklet and on the answer sheet you will hand in. Also, print your name on the line provided on the answer sheet. 4. There is one answer sheet for this exam. Fill in the circle for the correct answer(s) completely. If you believe that a question has more than one correct answer fill in all answers for that question completely. If you wish to change an answer, be sure to erase cleanly. Make sure that you use your biochemistry ID number to fill in the ID box. You should use the three leftmost boxes to insert your number. 5. When you are finished with the exam, return both the test booklet and the answer sheet. The test booklet will be returned to you when the grading is complete. Be sure to pick up the next section of the course syllabus as you leave. 6. Questions will not be allowed during the exam. If you believe there is a typographical error do the best you can with the information available. Do not spend extra time on the question. If it is determined that the information presented is ambiguous, or in error, then the question will not be counted in the final scoring. 7. Following the last page of the exam are two blank pages for your use. Answers will be posted on November 14 th, at 2:00 pm, assuming that all students attend the exam at its scheduled time. 8. You will have 3.5 hours (until 12:00 pm) to complete this exam. Good luck. Page 1 of 20

2 1. (2 points) The glucose sensor in liver cells is thought to be composed of which ONE of the following enzyme complexes? A. Glycogen synthase/protein phosphatase I B. Glycogen phosphorylase kinase/glycogen phosphorylase C. Glycogen phosphorylase/protein inhibitor I D. Glycogen phosphorylase/protein phosphatase I E. Protein phosphatase I/protein inhibitor I F. Protein kinase A/protein inhibitor I 2. (2 points) Starting with liver glycogen, how many high energy bonds must be cleaved for a glucose residue from liver glycogen to be converted to glucose-6-phosphate in a brain cell? Choose the ONE best answer. A. 0 B. 1 C. 2 D. 3 E. 4 F (1 point) Which ONE of the following fatty acids would provide the greatest amount of ATP when fully oxidized to carbon dioxide and water in humans? A. Palmitic acid B. Oleic acid C. Stearic acid D. Linoleic acid E. Linolenic acid 4. (1 point) Which ONE of the following activities requires that the fatty acid synthase be configured as a dimer? A. The ketoacyl synthase (condensing enzyme) B. The malonyl transacylase C. The ketoacyl reductase D. The enoylacyl reductase E. The -ketothiolase Page 2 of 20

3 Questions 5-9 (1 point each) will be answered from the lettered list (A-D) below. Consider Dr. Drake s metabolism while he is in the middle of running a marathon. Assuming his last meal was two hours prior to beginning the race, what would be the phosphorylation state and activity of the following enzymes (one answer per question)? 5. Liver acetyl-coa carboxylase 6. Muscle phosphorylase kinase 7. Liver glucose-6-phosphate dehydrogenase 8. Liver HMG-CoA reductase 9. Muscle protein inhibitor I A. Phosphorylated and active B. Phosphorylated and inactive C. Not phosphorylated and active D. Not phosphorylated and inactive 10. (2 points) Types of diabetes can result from mutations in all of the following proteins EXCEPT for which ONE? A. Pancreatic glucokinase B. Insulin receptor tyrosine kinase domain C. Insulin receptor binding domain D. Auto-immune antibodies directed against insulin E. Pancreatic PFK (2 points) An enzyme system which uses the ETF:CoQ oxidoreductase system to funnel electrons into the electron transport chain is which ONE of the following? A. Succinate dehydrogenase B. NADH dehydrogenase C. Lactate dehydrogenase D. Mitochondrial glycerol-3-phosphate dehydrogenase E. Isocitrate dehydrogenase F. Pyruvate dehydrogenase 12. (2 points) A major difference between type I and type II diabetes is that type II diabetics, while displaying elevated glucose levels, do not produce ketone bodies. This occurs because of which ONE of the following reasons? A. Glucose blocks the initial step of ketone body formation B. The insulin receptor is uncoupled from sending intracellular signals C. Hexokinase is inhibited by glucose in muscle cells D. There is sufficient insulin produced to allow the liver to respond, but not the muscles E. Fatty acid oxidation is increased in the liver of type I diabetics as compared to type II Page 3 of 20

4 13. (1 point) An accumulation of fatty acids in the liver due to impaired fatty acid oxidation can lead to an elevation of which ONE of the following? A. Circulating albumin levels B. Circulating free fatty acid levels C. Circulating glucose levels D. Circulating chylomicron levels E. Circulating VLDL levels 14. (1 point) A starving individual would have a respiratory quotient of which ONE of the following? A. 0.3 B. 0.5 C. 0.7 D. 1.0 E (2 points) Patient s with von Gierke s disease accumulate liver glycogen to a greater extent than individuals without the disease. This is due to which ONE of the following? A. Glucose-6-phosphate inhibition of phosphorylase-a B. Glucose-6-phosphate inhibition of phosphorylase-b C. Glucose-6-phosphate inhibition of phosphorylase kinase-a D. Glucose-6-phosphate inhibition of phosphorylase kinase-b E. Glucose-6-phosphate activation of glycogen synthase-i F. Glucose-6-phosphate activation of glycogen synthase-d 16. (2 points) The correct sequence of events in fatty acid oxidation of saturated fatty acids is which ONE of the following? A. Oxidation, hydration, oxidation, cleavage B. Reduction, oxidation, dehydration, oxidation, cleavage C. Hydration, oxidation, dehydration, oxidation cleavage D. Hydration, reduction, dehydration, reduction, cleavage E. Oxidation, hydration, reduction, cleavage F. Reduction, hydration, oxidation, cleavage Page 4 of 20

5 17. (2 points) The net ATP yield from the oxidation of a C 17:0 fatty acid would be closest to which ONE of the following? A. 60 B. 80 C. 100 D. 120 E (2 points) ATP is generated at the fastest rate by which ONE of the following pathways? A. Liver glycogen to muscle lactate B. Muscle glycogen to muscle lactate C. Muscle glycogen to carbon dioxide and water D. Liver glycogen to carbon dioxide and water E. Muscle fatty acid oxidation F. Liver fatty acid oxidation 19. (2 points) Which of the following events do NOT occur in the liver when blood glucose levels drop? This question may have more than one correct answer. Be sure to indicate all correct answers on the answer sheet. A. Activation of a Gs protein B. Inhibition of glycogen synthase C. Elevation of camp levels D. Synthesis of malonyl-coa E. Activation of a tyrosine kinase F. Activation of glycogen phosphorylase G. Phosphorylation of hormone sensitive lipase Page 5 of 20

6 20. (2 points) Hypoglycemia can result from the reduced activity of which of the following enzymes? This question may have more than one correct answer. Be sure to indicate all correct answers on the answer sheet. A. Glucokinase B. Medium chain acyl-coa dehydrogenase C. Lactate dehydrogenase D. Glucose-6-phosphate dehydrogenase E. Glucose-6-phosphatase F. Muscle glycogen phosphorylase 21. (2 points) All of the following can protect against radical damage EXCEPT for which ONE? A. Reduced glutathione B. Vitamin E C. Superoxide dismutase D. Glutathione peroxidase E. Vitamin B1 F. Vitamin C Questions (2 points each) should be answered from the lettered lists below. Cofactors play very important roles in metabolism. Each question lists a cofactor, or the precursor of a cofactor. Choose one answer from choices A through J to match an enzyme which requires this cofactor. Then, from answers K through O, choose the one pathway which utilizes this cofactor. Thus, each question should have two answer. 22. Vitamin B Vitamin B6 24. Riboflavin 25. Thiamine pyrophosphate 26. Biotin A. Methyl-malonyl-CoA mutase B. Glycogen phosphorylase C. Acyl-CoA dehydrogenase D. Transketolase E. Transaldolase F. Glycogen synthase G. Pyruvate carboxylase H. Acyl-CoA synthetase I. Fatty acid synthase J. Isocitrate dehydrogenase K. Fatty acid oxidation (including odd chain oxidation) L. Glycogen metabolism M. Glycolysis N. HMP shunt pathway O. Gluconeogenesis Page 6 of 20

7 27. (2 points) A reduced activity of the ETF:CoQ reductase would affect energy yield from which of the following pathways? This question may have more than one correct answer. Indicate all correct answers on the answer sheet. A. Cytoplasmic NADH via the malate/aspartate shuttle B. The TCA cycle C. Cytoplasmic NADH via the glycerol-3-phosphate shuttle D. Cholesterol oxidation E. Fatty acid oxidation 28. (2 points) An individual on a diet has decided to eat a lunch every day which consists of 10 grams of protein, 40 grams of carbohydrate, 20 grams of fat, and 30 grams of ethanol. Approximately how many calories would this be every day? Choose the ONE best answer. A. 200 B. 400 C. 600 D. 800 E (1 point) The tricarboxylic acid citrate has multiple roles in metabolism. Which ONE of the following is not a role for citrate in metabolism? A. The initial product of the TCA cycle reactions B. Transports acetyl-coa equivalents across the inner mitochondrial membrane C. Allosteric modifier of a key glycolytic enzyme D. Allosteric modifier of a key enzyme in fatty acid metabolism E. Allosteric modifier of a key enzyme in the hexose monophosphate shunt pathway 30. (2 points) Oxygen radicals can be formed via the reaction of oxygen with which ONE of the following? A. FADH 2 B. NADH C. Coenzyme Q D. Cholesterol E. Vitamin C F. Vitamin E Page 7 of 20

8 31. (1 point) Elongation of an existing fatty acid is similar to de novo fatty acid synthesis in all of the following ways EXCEPT for which ONE? A. The substrate is an acyl-coa B. Malonyl-CoA is the carbon donor C. Carbon dioxide is released in the condensation reaction D. NADPH is used for reducing power E. All reactions occur using cytoplasmic, non membrane bound, enzymes 32. (2 points) Which of the following fatty acids are derived from oleic acid? This question may have more than one correct answer. Indicate all correct answers on the answer sheet. A. Cis 9 C 20:1 B. Cis 6,9 C 18:2 C. Cis 6,9,12 C 18:3 D. Cis 9,12,15 C 18:3 E. Cis 9,11 C 20:2 F. Cis 5 C 18:1 33. (2 points) Consider the conversion of ribose-5-phosphate to glucose-6-phosphate. Which of the following substrates are NOT required for this conversion to occur? This question may have more than one correct answer. Indicate all correct answers on the answer sheet. A. NADP + or NADPH B. Sedoheptuolose-7-phosphate C. NAD + or NADH D. Glyceraldehyde-4-phosphate E. Oxaloacetate F. Fructose-6-phosphate 34. (2 points) Assume a person has reduced their caloric intake by 180 Calories per day, without increasing their exercise level. How many days would it take this person to lose one pound of weight? Choose the ONE best answer. A. 5 B. 10 C. 15 D. 20 E. 25 Page 8 of 20

9 35. (1 point) Leptin is produced by which ONE of the following cell types? A. Liver B. Muscle C. Brain D. Fat E. Pancreas ID No.: 36. (2 points) The substrates for gluconeogenesis under long-term starvation conditions are derived from which of the following tissues or cell types? This question may have more than one correct answer. Indicate all correct answers on the answer sheet. A. Brain B. Liver C. Pancreas D. Muscle E. Adipocyte F. Intestine 37. (1 point) One can differentiate between a starving individual and a type I diabetic (undiagnosed) by blood analysis of which of the following metabolites? Choose the ONE best answer. A. Ketone bodies B. Acyl-carnitine C. Glucose D. Dicarboxylic acids E. Glycerol Page 9 of 20

10 Questions 38 through 45 (1 point each) are true/false questions. Answer by darkening either T or F on the answer sheet. 38. Under conditions of rapid fatty acid synthesis the HMP shunt pathway is inactive. 39. Glucose-6-phosphate dehydrogenase is inhibited by NADPH. 40. Ribulose, Xyulose, Sedoheptulose and fructose are ketoses. 41. Ribose-5-phosphate can be directly generated via both oxidative and non-oxidative reactions of the HMP shunt pathway 42. Reagents which block free sulhydral activity will inhibit transaldolase activity 43. The net ATP yield from the conversion of 3 glucose-6-phosphate to 3 ribose-5-phosphate and 1 glyceraldehyde-3-phosphate is Superoxide is not a naturally occurring radical in biological systems. 45. The oxidative reactions of the HMP shunt pathway generate carbon dioxide from carbon 1 of glucose. 46. (2 points) While in your pediatric rotation you see a young boy in the emergency room. The boy had a history of developing a fever two days ago, and did not eat well for the past two days, with occasional vomiting. Earlier this day the child was put down for a nap, and when checked 15 minutes later was not breathing. The parents were able to revive the child and immediately brought him to the hospital. At present, the child is breathing normally but is very lethargic and mainly non-responsive. Laboratory tests reveal an extremely low blood glucose level, virtually no ketone bodies, and the presence of 6-10 carbon long dicarboxylic acids. The metabolic defect in this child is most likely due to a reduced activity of which ONE of the following enzmes? A. Acetyl-CoA carboxylase B. Glucose-6-phosphatase C. Carnitine-palmitoyl transferase I D. Medium chain acyl-coa dehydrogenase E. Fatty acid synthase Page 10 of 20

11 47. (2 points) You are having a busy day in the pediatric ER. Just hours after seeing the patient described in question 46 you see another patient with the same symptoms and history. However, the blood work from this patient showed low blood glucose levels, elevated levels of ketone bodies, and no dicarboxylic acids. Acyl-carnitine derivatives are also missing from the blood. In this case the defect in the patient is most likely which ONE of the following enzymes? A. Acetyl-CoA carboxylase B. Glucose-6-phosphatase C. Carnitine-palmitoyl transferase I D. Medium chain acyl-coa dehydrogenase E. Fatty acid synthase Questions (1 point each) should be answered from the lettered list below. Consider the case of a medical student studying for exams who, for the past 24 hours, has only studied and has not eaten. For each enzyme listed indicate if it will be phosphorylated or not, and whether it is active or not. Each question will have just ONE answer. 48. Liver glycogen phosphorylase 49. Liver fatty acid synthase 50. Liver pyruvate carboxylase 51. Liver pyruvate kinase 52. Liver pyruvate dehydrogenase 53. Liver protein inhibitor I 54. Liver protein phosphatase I A. The enzyme is phosphorylated and active B. The enzyme is phosphorylated and inactive C. The enzyme is not phosphorylated, but is active D. The enzyme is not phosphorylated, but is inactive Page 11 of 20

12 55. (4 points) From the list of lettered items below (A-O), select the SIX items which, if deficient, would be most likely to result in steatorrhea (fatty stools). A. Pancreatic Lipase B. Hormone Sensitive Lipase C. Cholesterol Esterase D. Colipase E. Lipoprotein Lipase F. Hepatic lipase G. 7- -hydroxylase H. apoa-1 I. apob100 J. apoc-ii K. apoc-iii L. apoe M. Cholecystokinin N. Secretin O. HMG-CoA Reductase 56. (3 points) From the list of lettered items below (A-N), select FIVE which are components of mixed micelles. A. apoa-1 B. apob100 C. apoc-ii D. apoc-iii E. apoe F. Colipase G. Bile salts H. 2-monoacylglycerol I. Lysophospholipids J. Phospholipids K. Cholesterol Esters L. Cholesterol M. Free Fatty Acids N. Triglycerides 57. (2 points) From the list of lettered items below, select the TWO which are most important in helping the digestive system to deal with the low ph commonly encountered in the upper intestinal tract (duodenum). A. Pancreatic lipase B. Hormone sensitive lipase C. Cholesterol esterase D. Colipase E. Lipoprotein lipase F. Hepatic lipase G. Secretin H. Cholecystokinin I. Conjugation of bile acids to form bile salts Page 12 of 20

13 Questions 58 through 61 should be answered from the lettered list (A-L) below. An answer may be used more than once, although each question will have a defined number of answers. 58. (4 points) Select the FIVE changes in serum lipoprotein levels which would be likely to occur in response to a deficiency in microsomal triglyceride transport protein (MTP). 59. (2 point) Select the ONE change in serum lipoprotein levels which would be most likely to occur in response to a deficiency in ABCA (2 points) Select the FOUR changes in serum lipoprotein levels which have actually been found to occur in cases of lipoprotein lipase deficiency. 61. (2 points) Select the TWO changes in serum lipoproteins which would be most likely to occur in response to a deficiency in apolipoprotein B-48 (apob-48). A. Increased chylomicrons B. Decreased chylomicrons C. Increased chylo remnants D. Decreased chylo remnants E. Increased VLDL F. Decreased VLDL G. Increased IDL H. Decreased IDL I. Increased LDL J. Decreased LDL K. Increased HDL L. Decreased HDL 62. (2 points) A patient with markedly elevated levels of serum LDL and a family history of atherosclerotic heart disease is suspected of having familial hypercholesterolemia. A test of the binding of LDL binding to the patient's cells reveals normal LDL binding but no further metabolism of the LDL by the cells. The most likely explanation for these results would be which ONE of the following? A. The patient does not have familial hypercholesterolemia B. A defect in the N-terminal, extracellular domain of the LDL receptor C. A defect in the EGF-like extracellular domain of the LDL receptor D. A defect in the C-terminal, cytoplasmic domain of the LDL receptor E. A defect in acyl cholesterol acyltransferase (ACAT) Page 13 of 20

14 63. (2 points) An article in the June 2002 issue of the Journal of Nutrition reported that S-allyl cysteine, which is found at high levels in garlic, increases the phosphorylation of HMG CoA reductase. Which of the effects listed below would be likely to result from ingesting large amounts of garlic? There may be more than one correct answer to this question; indicate all correct answers on the answer sheet. A. Increased cholesterol biosynthesis B. Decreased cholesterol biosynthesis C. Increased serum LDL levels D. Decreased serum LDL levels E. Decreased frequency of vampire bites 64. (3 points) Which THREE of the following would be expected to have anti-athrogenic effects in the intimal layer of arteries? A. Increased LDL oxidation B. Decreased LDL oxidation C. Increased levels of monocyte chemoattractant protein (MCP) D. Decreased levels of monocyte chemoattractant protein (MCP) E. Increased numbers of scavenger receptors F. Decreased numbers of scavenger receptors G. Increased serum VLDL H. Decreased serum VLDL Questions (1 point each) should be answered from the lettered list (A-E) below. Choose the ONE best answer for each question. An answer may be used more than once. 65. A patient suspected of having congenital adrenal hyperplasia (CAH) is found to have decreased levels of cortisol and estradiol with normal levels of aldosterone. A defect in which ONE of the listed enzymes could account for these results? 66. Another patient suspected of having CAH is found to have decreased levels of aldosterone, cortisol and testosterone. A defect in which ONE of the listed enzymes could account for these results? 67. A patient with decreased levels of aldosterone and testosterone but normal levels of cortisol would be expected to have a deficiency in which ONE of the listed enzymes? A Hydroxylase B Hydroxylase C. 3- -hydroxysteroid dehydrogenase D. 17- hydroxylase E. None of the above Page 14 of 20

15 68. (2 points) Reverse cholesterol transport is important in preventing atherosclerosis. Changes in which TWO of the items listed below would be most likely to increase reverse cholesterol transport? A. Increased LCAT B. Decreased LCAT C. Increased apoa-1 D. Decreased apoa-1 E. Increased ACAT F. Decreased ACAT G. Increased 7- Hydroxylase H. Decreased 7- -Hydroxylase 69. (2 points) Which TWO of the following mechanisms are NOT used by the body for regulating the amount of total body cholesterol? A. Rate of LDL receptor synthesis B. Rate of HMG CoA reductase synthesis C. Rate of HMG CoA reductase degradation D. Phosphorylation of HMG CoA reductase E. Activation of pancreatic lipase by colipase F. Phosphorylation of hormone sensitive lipase G. Activity of 7- -hydroxylase 70. (2 points) On the basis of body mass index (BMI), an individual who is 2 meters tall and weighs 98 kilograms would be considered to be which ONE of the following? A. Of normal weight B. Pre-obese C. Obese 71. (2 points) Insulin directly stimulates which of the following activities in adipocytes? This question may have more than one correct answer. Be sure to indicate all correct answers on the answer sheet. A. Fatty acyl CoA synthetase B. Glucose transport C. Hormone sensitive lipase D. Secretion of lipoprotein lipase E. Activation of glucose-6-phosphatase F. Inhibition of glucose-6-phosphate dehydrogenase Page 15 of 20

16 Questions (1 point each) should be answered from the lettered list (A-E) below. For each protein listed a point mutation has occurred causing the Ser, Thr, or Tyr at the residue that is phosphorylated as part of the normal regulatory control to be changed to an alanine, which cannot be phosphorylated. Assume that this mutation does not affect the active site of the enzyme, just the ability of the enzyme to be phosphorylated. Select the ONE answer which best describes the metabolic effect of the mutation on the enzyme. 72. Hormone sensitive lipase 73. HMG CoA reductase 74. Protein inhibitor I (phosphatase inhibitor I) A. Increased cholesterol biosynthesis B. Decreased cholesterol biosynthesis C. Increased fatty acid release D. Decreased fatty acid release E. Increased triglyceride synthesis F. Decreased triglyceride synthesis 75. (2 points) Which TWO of the following changes would be likely to result in a decrease in the amount of adipose tissue? A. Increased HDL B. Decreased HDL C. Increased hepatic lipase activity D. Decreased hepatic lipase activity E. Increased fatty acid synthase activity F. Decreased fatty acid synthase activity G. Increased acetylcoa carboxylase activity H. Decreased acetyl CoA carboxylase activity 76. (2 points) An increase in BMI is likely to give rise to which of the following effects? There may be more than one correct answer to this question. Indicate all correct answers on the answer sheet. A. Increased serum VLDL B. Increased glucose utilization by muscle C. Increased hepatic gluconeogenesis D. Increased serum insulin levels E. Increased serum glucagon levels F. Increased glycogenolysis Page 16 of 20

17 77. (3 points) Which THREE of the following proteins are part of the mechanism by which ACTH activates cortisol synthesis? A. 7- -Hydroxylase B. HMG CoA reductase C. StAR protein D. ACAT E. Cholesterol esterase F. Protein kinase A 78. (3 points) Which TWO of the following compounds are NOT synthesized from mevalonate? A. Triglycerides B. Cholesterol C. Phospholipids D. Bile acids E. Aldosterone F. Coenzyme Q G. Dolichol phosphate 79. (2 points) The serum lipoproteins consist of a central core of apolar compounds and a surface coat of more polar compounds. Which TWO of the following compounds compose the bulk of the central core? A. Cholesterol B. Cholesterol esters C. Bile salts D. Apolipoproteins E. Triglycerides F. Phospholipids 80. (2 points) Which ONE of the following is not an enzyme or an intermediate in the production of triglycerides in adipocytes? A. Diglyceride B. Phosphatidic acid C. Hormone sensitive lipase D. Free fatty acids E. Fatty acyl CoA transferase Page 17 of 20

18 81. (2 points) Which lipoprotein contains the lowest ratio of lipids to protein? Choose the ONE best answer. A. Chylomicrons B. IDL C. VLDL D. LDL E. HDL 82. (2 points) Fatty acids from adipose tissue are transported to sites of utilization in the form of which ONE of the following? A. Triglycerides bound to serum albumin B. Very low density lipoproteins (pre-beta lipoproteins) C. High density lipoproteins D. Chylomicrons E. Free fatty acids bound to serum albumin 83. (2 points) Adipose tissue contains little or none of which of the following enzymes? This question may have more than one correct answer. Indicate all correct answers on the answer sheet. A. Glucokinase B. Hormone-sensitive lipase C. Glyceraldehyde 3-phosphate dehydrogenase D. Glycerol kinase E. Glycerol phosphate dehydrogenase 84. (2 points) An individual with an ACAT deficiency would be likely to exhibit which ONE of the following conditions? A. An inability to form cholesteryl esters in the plasma B. A decrease in mature HDL particles C. An increase in the cholesteryl ester content of chylomicrons D. A decreased ability to store cholesterol oleate in the cell Page 18 of 20

19 85. (2 points) Cholestyramine is used to reduce serum cholesterol because of its ability to interfere with the entero-hepatic circulation of bile salts, resulting in increased amounts of bile salts in the feces. When this drug is given, the liver responds with increased synthesis of which of the following? This question may have more than one correct answer. Indicate all correct answers on the answer sheet. A. Cholesterol B. Bile salts C. Mevalonate D. Vitamins A, E, K E. Lecithin F. Fatty acids 86. (2 points) Which of the following is true of HDL particles? This question may have more than one correct answer. Indicate all correct answers on the answer sheet. A. Are discoid when nascent B. When present at high concentration increase the risk for ischemic heart disease C. Can donate apoproteins to other particles D. Contain no cholesteryl ester 87. (2 points) Which of the following statements is true of LDL particles? This question may have more than one correct answer. Indicate all correct answers on the answer sheet. A. They are hydrolyzed by lipoprotein lipase B. They are derived from HDL C. They are smaller than VLDL particles D. They are have only one type of apoprotein 88. (2 points) Which of the following are intermediates in the synthesis of cortisol and aldosterone? This question may have more than one correct answer. Indicate all correct answers on the answer sheet. A. Cholesterol B. Deoxycholic acid C. Estradiol D. Progesterone E. Pregnenolone F. Corticosterone Page 19 of 20

20 Answers to Exam II 1. D 2. B 3. C 4. A 5. DELETED 6. A 7. D 8. B 9. A 10. E 11. A or D 12. D or E 13. B or E 14. C 15. F 16. A 17. D 18. B 19. D,E,G 20. B,E 21. E 22. A, K 23. B, L 24. C, K 25. D, N 26. G, O 27. B, C, E 28. C 29. E 30. C 31. E 32. B, E 33. A, C, D, E 34. D 35. D 36. D, E 37. C 38. F 39. T 40. T 41. F 42. F 43. F 44. F 45. T 46. D 47. B 48. A 49. D 50. C 51. B 52. B 53. A 54. D 55. A, C, D, G, M. N 56. G, H, I, J, L, M 57. G, H, I 58. B, D, F, H, J 59. L 60. A, D, J, L 61. B, D 62. D 63. B, D 64. B, D, F 65. D 66. C 67. E 68. A, C 69. E, F 70. A 71. B, D 72. D 73. A 74. A or D 75. F, H 76. DELETED 77. C, E, F 78. A, C 79. B, E 80. C 81. E 82. E 83. A, D 84. D 85. A, B, C 86. A, C 87. D, C 88. DELETED Page 20 of 20