Blue_Exam_1 - BMB 462 Exam 1 Spring 2006 Name Student...

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Unformatted text preview: BMB 462 Exam 1 Spring 2006 Name: Student #: Select the QUE BE§I answer. 100 points total for exam. Questions 1-10 are worth 2pts. each, questions 11-30 are worth 4 points each. 1) Which of the following molecules or substances contain; or are derived fiom, fatty acids? 1. Phosphatidate ' 2. Prostaglandins 3. Sphingolipids 4. Triacylglycerols a) 1,2and3only b) 1and4only V c) 1,3and4only d)1,2,3and4 e) 2, 3, and4only 2) The primary role of hormone-sensitive lipase is to: a) hydrolyze triacylglycerols of plasma lipoproteins to supply fatty acids to various tissues. b) hydrolyze membrane phospholipids in hormone-producing cells. c) hydrolyze lipoproteins in the liver. d) play a role in the intestinal uptake of dietary fat. e) hydrolyze triacylglycerols stored in adipose tissue. 3) The compound shown to the right is n_ot a component of: a) ceramide. b) gangliosides. O HO—CH—CH=CH—(CH2)12—CH3 c) cardiolipin. I d) cerebrosides. R—C—N H—(lz—H e) sphmgomyelm. C H 2 _0 H 4) The type of membrane transport that uses ion gradients as the energy source is: a) secondary active transport. b) simple diffusion. c) facilitated diffusion d) passive transport. e) primary active transport. 5) Which of the fatty acids below is gamma-linolenic acid? 6) Which of the fatty acids below is linoleic acid? A. B.‘ C. D. E. \ / / / / \ . \ \ / 7) Which one is the polar portion of phosphatidylcholine? a) —CHZCH(NH3*)C00' b) -CH2CH2NH3+ c) -CH2CH2N(CH3)3+ d) -CH2-CH2-CH2-CH2NH3+ e) —CH2CH(OH)CH20H 8) A3—Isopentenyl pyrophosphate is a precursor for the synthesis of all the following except: a) prostaglandins b) ubiquinone c) Vitamin K d) Vitamin E e) testosterone 9) An integral membrane protein can be extracted with: a) a buffer of alkaline or acid pH. b) a chelating agent that removes divalent cations like Ca++. c) a solution of high ionic strength. d) a solution containing detergent. e) hot water. 10) The type of motion least common in biological membranes is: a) lateral diffusion of protein molecules in the lipid bilayer b) lateral diffusion of individual lipid molecules within the plane of each monolayer. c) flip-flop diffusion of phospholipid from one monolayer to the other. d) lateral diffusion of membrane proteins in the bilayer. e) random motion of the fatty acyl side chains in the interior of the phospholipid bilayer. Remember, questions 1-10 are worth Zpts. each. The following 20 questions (11- 30) are worth 4 points each. 11) The binding of glucagon to its receptor in adipose tissues causes which of the following to occur? CAMP levels to increase GTP to displace GDP on a Gas Protein kinase A to be activated Triacylglycerol synthesis to increase activation of phosphodiesterase. MFWP?‘ a) Only 2, 3, and 4 are correct _ b) Only 1, 2 and 4 only are correct c) Only 1 and 2 are correct d) - S‘nly 1, 2 and 3 are correct e) Only 2, 3 and 5 are correct 12) Which of the following is not an intermediate in the synthesis of cholesterol from acetyl- CoA? a) Mevalonate b) Isopentenyl pyrophosphate c) Squalene d) Malonyl-CoA e) beta-Hydroxy-beta-methylglutaryl-CoA (HMG-CoA) 13) How many acetyl CoA molecules would be produced and how many rounds of B-oxidation would be required for a 20 carbon fatty acid? a) 9 Acetyl CoA’s and 10 rounds of B-oxidation b) 10 Acetyl CoA’s and 9 rounds of B-oxidation c) 10 Acetyl CoA’s and 10 rounds of B-oxidation d) 9 Acetyl CoA’s and 9 rounds of B-oxidation e) none of the above are correct 14) Fatty acid synthase in humans produces palmitic acid. In the absence of any dietary fatty acids which of the following fatty acids can be synthesized from palmitic acid in humans? a) 20:1Al3 b) 16:2A5’6 c) 20:4A5’8’11’14 d) 18:2A7’9 6) none of the above fatty acids could be synthesized from palmitic acid in humans 15) CDP-diglyceride is not involved in the biosynthesis of: a) phosphatidylcholine. b) phosphatidylethanolamine c) sphingomyelin. d) phosphatidylglycerol. e) phosphatidylserine. 16) Which of the following is no_t involved in signal transduction by the [3-adrenergic receptor pathway? a) GTP-binding protein b) Diacylglycerol c) Cyclic AlVfl3 synthesis d) GTP hydrolysis e) All of the above are involved. 17) Fatty acids are activated to acyl-CoAs and the acyl group is further transferred to-carnitine because: ' ‘ a) acyl—CoAs easily cross the mitochondrial membrane, but the fatty acids themselves will not. b) acyl—carnitines readily cross the mitochondrial inner membrane, but acyl-CoAs do not. c) carnitine is required to oxidize NAD+ to NADH. J (1) fatty acids cannot be oxidized by FAD unless they are in the acyl—carnitine form. e) None of the above is true. 18) G-protein—coupled activation of phospholipase C results in a) activation of phosphodiesterase. b) inactivation of adenylate cyclase. c) decrease of inositol 1,4,5-trisphosphate (1P3). d) increase of phosphatidylinositol 4,5-bisphOSphate (PIP2). e) activation of protein kinase C. 19) The committed step in fatty acid synthesis is inhibited by a) increased protein kinase A (PKA) activity. b) increased cytoplasmic malonyl-CoA. c) increased cytosolic citrate. (1) increased insulin levels e) none of the above inhibit fatty acid synthesis 20) In describing the activity of membrane transporters, the constant K is: a) analogous to Vmgx for an enzyme-catalyzed reaction b) analogous to Ka for ionization of a weak acid. 0) analogous to Km for an enzyme-catalyzed reaction. d) proportional to the number of molecules of transporter per cell. e) the total rate of transport. 21) Which of these statements about triacylglycerol synthesis is correct? a) Humans can store more energy in glycogen than in triacylglycerols. b) It is not a hormone-sensitive process. c) Mammals are unable to convert carbohydrates into triacylglycerols. d) Phosphatidate is not on the pathway of triacylglycerol synthesis. e) Insulin stimulates conversion of dietary carbohydrate into triacylglycerols. 22) Which of these statements about cholesterol synthesis is true? a) Cholesterol is the only known natural product whose biosynthesis involves isoprene units. ‘ b) The activated intermediates in the pathway are GDP—derivatives. c) Only half of the carbon atoms of cholesterol are derived from Acetyl CoA. d) Squalene synthesis from farnesyl pyrophosphate results in the release of two moles of PPi for each mole of squalene formed. e) None of the above statements are true. 23) The enzyme required for both the biosynthesis of acetoacetate (a ketone body) and its utilization as a fuel in peripheral tissues is: a) succinyl CoA: acetoacetate CoA transferase. b) 3—hydroxy-3-methylglutaryl-COA synthase (HMG-CoA synthase). c) 3—hydroxy-3-methylglutaryl-COA lyase (HMG—CoA lyase) d) 3—ketothiolase (thiolase) e) D-beta-hydroxybutyrate dehydrogenase 24) In the synthesis of a single molecule of palmitic acid by Fatty acid synthase, which of the following reactions occurs only once? a) Reduction of the beta-keto group to an alcohol b) Transfer of a malonyl group to the acyl carrier protein c) The condensation reaction that releases C02 (1) Transfer of an acetyl group to beta-ketoacyl-ACP-synthetase e) All of the above occur more than once in the synthesis of palmitate 25) The intermediate in the enzymatic reaction that converts a free fatty acid to an acyl—CoA derivative is: a) an acyl group attached to a special cysteine —SH on the enzyme b) a carnitine—acyl intermediate - c) an acyl-ANIP derivative d) a carboxy-biotin derivative e) a fatty acid-pyrophosphate derivative 26) The primary route for cholesterol uptake by peripheral tissue in humans is mediated via: a) very low density lipoproteins b) low density lipoproteins c) high density lipoproteins d) Chylomicrons e) Intermediate density lipoproteins 27) The carbon atoms from a fatty acid with an odd number of carbons will enter the citric acid cycle as acetyl-CoA and: a) succinyl-CoA. b) Proponyl-CoA c) citrate. d) malate. e) a-ketoglutarate. 28) The following fatty acid, in which the indicated carbon is labeled with radioactive 14C, is fed to an animal: “CH3(CH2)9COOH After allowing 30 minutes for fatty acid beta oxidation, the radioactive label would most likely be recovered in what compound(s): a) acetyl-CoA. b) beta-hydroxy butyryl-CoA. c) both acetyl-CoA and propionyl-CoA. d) propionyl—CoA. e) palmitoyl-CoA. 29) All are true of membrane rafts (microdomains) except: a) They are enriched in cholesterol. b) They are enriched in sphingolipids. 0) They are enriched in GPI—anchored proteins. d) The raft lipids are enriched in polyunsaturated fatty acids. e) They are stabilized primarily by non—covalent interactions. 30) Which of these statements about the regulation of cholesterol synthesis is not true? a) Dietary cholesterol has essentially no effect on the synthesis of cholesterol in the liver. b) Failure to regulate cholesterol synthesis predisposes humans to atherosclerosis. c) High intracellular‘cholesterol stimulates formation of cholesterol esters. d) Insulin stimulates HMG—CoA reductase. e) All of the above statements are true. ...
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Blue_Exam_1 - BMB 462 Exam 1 Spring 2006 Name Student...

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