BIBC 102 – METABOLC BIOCHEM - FINAL RANDY HAMPTON SPRING QUARTER 2009 6/11/2009 1. The pentose phosphate pathway A) oxidizes glucose at the 6 carbon B) oxidizes glucose at the 1 carbon C) reduces NAD+ D) generates PRPP as a product 2. Complex I: A) gets electrons from NADPH B) generates NADH C) donates electrons to succinate D) produces ubiquinol 3. Lipoic acid A) will accept electrons and carry an acetyl group B) will accept electrons C) will carry an acetyl group D) will covalently react with pyruvate 4. Molecules A, B, and C, have reduction potentials of -.23, -0.1 and +.34 electron volts, respectively, in the cell. If they are involved in a set of sequential reactions that allow electrons to be passed from one to the next, which order delivers the most energy? A) electrons are passed from B to C, then from C to A B) electrons are passed from A to B, then from B to C C) electrons are passed from C to B, then from B to A D) electrons are passed from A to C, then from C to B 5. UDP-glucose A) directly donates a glucose to start a glycogen chain B) transfers phosphate to other molecules C) is a substrate in the Calvin cycle D) accepts electrons during the Krebs cycle 6. Glycogenin A) is the form of glycogen with no branches B) is a relative of glycogen found in plants C) is a drug that inhibits glycogen production D) is a protein that initiates glycogen synthesis 7. Which anapleurotic enzyme includes oxaloacetate as a product? A) malic enzyme B) pyruvate kinase C) PEP kinase D) pyruvate carboxylaseBIBC 102 – METABOLC BIOCHEM - FINAL RANDY HAMPTON SPRING QUARTER 2009 6/11/2009 8. The F0 subunit of the ATP synthase A) is reduced by electrons as they reach the end of the respiratory chain B) binds both ADP and ATP C) is found in the intermembrane space of the mitochondrion D) transports protons across the membrane 9. There are two enzymes which we lack that allow plants and microorganisms to make glucose from fat. What are they called? A) Isocitrate lyase and malate synthase B) Isocitrate dehydrogenase and malate synthase C) Isocitrate mutase and malate synthase D) Isocitrate lyase and glyoxalate synthase 10. The PDH complex A) is found in the cytosol of mammalian cells B) uses PLP to convert pyruvate into alanine C) uses TPP, lipoic acid, FAD, and NAD+ as cofactors D) does not function in absence of oxygen 11. The cofactor TPP A) activates CO2 for a number of transfer reactions B) functions in moving amino groups from one molecule to another C) attacks carbonyls with a nitrogen nucleophile, allowing catalysis D) uses a carbanion to attack carbonyl groups on substrates 12. The pictured structure is part of what cofactor A) NAD B) PLP C) TPP D) biotin 13. What molecule includes this structural motif? A) NADH B) NADPH C) both D) neither 14. Which gluconeogeneic step uses a glycolytic enzyme? A) conversion of glucose-6-phosphate to glucose B) conversion of pyruvate to phosphoenolpyruvate C) conversion of 1, 3 bPG and NADH to G3P and NAD+ D) conversion of fructose 1,6 bisphosphate to fructose 6 phosphateBIBC 102 – METABOLC BIOCHEM - FINAL RANDY HAMPTON SPRING QUARTER 2009 6/11/2009 B A 15. If you knew ΔG'o for a reaction, what do you need to calculate the ΔG for the actual conditions in which the reaction is occurring? A) You’re done! It is the same B) You need ΔG‡ , the activation energy, as well C) You need to know the Km and Vmax for the enzyme involved D) You need the concentrations of all reactants and productso 16. kcat is a measure of A) how tightly a ligand binds to a protein B) how easily an enzyme is saturated with a substrate C) an enzyme's maximum rate of catalysis D) how specific an enzyme is for its substrate 17. If the activation energy of a reaction increases by 4kJ/mole A) the reaction will be accelerated by a factor of e4/RT B) The ΔG will be decreased by 4kJ/mole C) the reaction will be slowed by a factor of e4/RT D) the reaction will be accelerated by a factor of 4/RT 18. An enzyme is catalyzing a reaction in a beaker, accelerating the rate by a factor of 107. The solution is then placed in a microwave, which totally inactivates the enzyme. Once the beaker is back to normal temperature, what is now going on in the beaker? A) the forward reaction is slowed by a factor of 107 B) The reverse reaction is slowed by a factor of 107 C) The equilibrium constant is lowered D) Both A and B 19. Enzyme II has a Km that is twice the Km of enzyme I. What is the rate of enzyme I when its substrate concentration is equal to the Km of enzyme II A) 1/2 of the maximum rate B) 2/3 of the maximum rate C) 3/4 of the maximum rate D) 1/2 the Vmax of enzyme II 20. The picture shown is a Lineweaver-Burke plot for enzymes A and B. Which statement is the most accurate? A) B has a smaller Km than A B) B has a bigger Vmax than A C) A and B have the same Vmax; A has a smaller Km D) A and B have the same Km; A has a smaller Vmax Breath Here….BIBC 102 – METABOLC BIOCHEM - FINAL RANDY HAMPTON SPRING QUARTER 2009 6/11/2009 CDEFGHIJBA Z23456789101 21-27 Big Wheel Keep on Turnin', Proud Carbons Keep on Burnin..." The following questions are about the Krebs cycle and two upstream reactions, depicted in the schematic. The LETTERS refer to molecules, and the NUMBERS refer to the reactions, or the enzymes that catalyze those reactions. Each line segment or arrow is a single enzymatic step. For each question, choose the BEST answer. Hints: Reaction 1 (A to Z) is lactate dehydrogenase; molecule D is isocitrate 21. The reaction in which the same choice of two indistinguishable prochiral groups is always selected for movement to a new carbon A) 1 B) 8 C) 4 D) 10 22. Production of CO2 occurs in which reactions: A) 4 and 5 B) 5, 6 C) 5 , 6, and 2 D) 5, 6, and 10 23. An unsaturated dicarboxylic acid(s): A) A B) G C) G and H D) H 24. Complex II of the respiratory chai A) 1 B) 2 C) 8 D) none 25. Directly converted to PEP in gluconeogenesis A) J B) G C) C D) A 26. Shuttled out of the mitochondrion to provide acetyl groups for fatty acid and cholesterol synthesis A) C B) I C) Z D) JBIBC 102 – METABOLC BIOCHEM - FINAL RANDY HAMPTON SPRING QUARTER 2009 6/11/2009 27. Reactions that use CoA-SH as a substrate A)
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