Name ___________________________ Student ID # _____________________ Chemistry 153A-2 Final Examination Spring 2004 Prof. J. S. Valentine ¾ There are 15 pages total. Be sure that you have all pages and that you have put your name on all pages. ¾ Answer all questions in the space provided. (Answers written elsewhere will not be graded.) Multiple choice questions must be answered on p. 3. ¾ Look over the entire exam before you start. Be sure you leave yourself enough time to answer all the questions that you know first. Good luck! Questions Points Your Score Part I: Multiple Choice 40 Part II: Short Answer 60 Part III: Extra Credit (8) Total 100 ∆G = ∆H – T∆S ∆G’° = -RT lnK’eq ∆G = ∆G’° + RT ln([products]/[reactants]) ∆G = -nℑ∆E ∆E = E’°(acceptor) – E’°(donor) ∆Gt = RT ln(C2/C1) + zℑ∆ψ Keq = e-∆G°/RT aA = γA[A] Henderson Hasselbach: pH = pKa + log([A-]/[HA]) Nernst: ∆Go' = -nF∆Eo' v0 = Vmax[S] Km + [S] 1 KM 1 ______ = _______ + ______ Vo Vmax[S] Vmax Avogadro’s number: N = 6.022 x 1023 /mol Boltzmann constant: k = 1.381 x 1023 J/K Faraday’s constant: ℑ = 96,480 J/V x mol Gas constant: R = 8.314 J/mol K 1Name ___________________________ APPROXIMATE pKa VALUES OF IONIZABLE AMINO ACIDS AND PEPTIDE GROUPS GROUP pKa α-carboxyl of free amino acid 2 α-amino of free amino acid 9.6 C-terminal carboxyl 3 N-terminal amino 8 R group of Asp 4 R group of Glu 4 R group of His 6 R group of Cys 8.5 R group of Tyr 10 R group of Lys 10.5 R group of Arg 12.5 2Name ___________________________ Record your answers to the multiple-choice questions on this page. 1) A B C D E 2) A B C D E 3) A B C D E 4) A B C D E 5) A B C D E 6) A B C D E 7) A B C D E 8) A B C D E 9) A B C D E 10) A B C D E 11) A B C D E 12) A B C D E 13) A B C D E 14) A B C D E 15) A B C D E 16) A B C D E 17) A B C D E 18) A B C D E 19) A B C D E 20) A B C D E 3Name ___________________________ Part I: Multiple Choice: (2 points each) 1. Enzymes are potent catalysts because they: A) are consumed in the reactions they catalyze. B) are very specific and can prevent the conversion of products back to substrates. C) drive reactions to completion while other catalysts drive reactions to equilibrium. D) increase the equilibrium constants for the reactions they catalyze. E) lower the activation energy for the reactions they catalyze. 2. In competitive inhibition, an inhibitor: A) binds at several different sites on an enzyme. B) binds covalently to the enzyme. C) binds only to the ES complex. D) binds reversibly at the active site. E) lowers the characteristic Vmax of the enzyme. 3. When the linear form of glucose cyclizes, the product is a(n): A) anhydride B) glycoside C) hemiacetal D) lactone E) oligosaccharide 4. Which of the following is not a reducing sugar? A) Fructose B) Glucose C) Glyceraldehyde D) Ribose E) Sucrose 5. Which of the following best describes the cholesterol molecule? A) Amphipathic B) Nonpolar, charged C) Nonpolar, uncharged D) Polar, charged E) Polar, uncharged 4Name ___________________________ 6. An integral membrane protein can be extracted with: A) a buffer of alkaline or acid pH. B) a chelating agent that removes divalent cations. C) a solution containing detergent D) a solution of high ionic strength E) hot water 7. The ∆G'° values for the two reactions shown below are given. Oxaloacetate + acetyl-CoA + H2O citrate + CoASH ∆G'°= -32.2 kJ/mol citrate synthase Oxaloacetate + acetate citrate ∆G'°= -1.9 kJ/mol citrate lyase What is the ∆G'° for the hydrolysis of acetyl-CoA? (acetyl-CoA + H2O acetate + CoASH) A) -34.1 kJ/mol B) -32.2 kJ/mol C) -30.3 kJ/mol D) +61.9 kJ/mol E) +34.1 kJ/mol 8. Which of the following statements is incorrect? A) Aerobically, oxidative decarboxylation of pyruvate forms acetate that enters the citric acid cycle. B) In anaerobic muscle, pyruvate is converted to lactate. C) In yeast growing anaerobically, pyruvate is converted to ethanol. D) Reduction of pyruvate to lactate regenerates a cofactor essential for glycolysis. E) Under anaerobic conditions pyruvate does not form because glycolysis does not occur. 9. Which of the following is not true of the citric acid cycle? A) All enzymes of the cycle are located in the cytoplasm, except succinate dehydrogenase, which is bound to the inner mitochondrial membrane. B) In the presence of malonate, one would expect succinate to accumulate. C) Oxaloacetate is used as a substrate but is not consumed in the cycle. D) Succinate dehydrogenase channels electrons directly into the electron transfer chain. E) The condensing enzyme is subject to allosteric regulation by ATP and NADH.
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