QUIZ 4, BICH 410 (MWF 1:50 PM), Friday, Dec. 1, 1995
Clearly circle the letter corresponding to your answer for each problem. There are seven problems, six of which count 3 points, and one is worth 2 points. No partial credit given for multiple-choice questions.
R = 8.315 J/moleK
Faraday constant = 96,480 J/mole-volt
1) Which of the following statements is true about complex I (NADH dehydrogenase) of the mitochondrial electron transport chain?
- A. The electron donor is succinate.
- B. The overall redox reaction performed by this complex is the oxidation of ubiquinone by NADH.
- C. Protons are pumped into the matrix of the mitochondrion.
- D. Electrons are passed through multiple carriers, including an iron-sulfur protein.
- E. Oxygen is the ultimate electron acceptor for this complex.
2) Fatty acids are a component of:
- A. sterols
- B. vitamin D
- C. glycerol
- D. diacylglycerol
- E. cholesterol
3) Consider the transport of glucose into an erythrocyte by facilitated diffusion. When the glucose concentrations are 5 mM on the outside and 0.1 mM on the inside, the free-energy change for glucose uptake into the cell is (temperature of cell is 37 degrees C):
- A. about 10 kJ/mole.
- B. less than 2 kJ/mole.
- C. about 30 kJ/mole.
- D. about 100 kJ/mole.
- E. impossible to calculate without knowledge of the membrane potential.
4) All of the following contribute to the large, negative, free-energy change upon hydrolysis of compounds such as ATP, phosphoenolpyruvate and 1,3-bisphosphoglycerate except:
- A. electrostatic repulsion in the reactant.
- B. stabilization of products by ionization.
- C. low activation energy of forward reaction.
- D. stabilization of products by isomerization.
- E. stabilization of products by extra resonance forms.
5) The standard reduction potential of the NAD+/NADH half reaction is -0.32 V. The standard reduction potential of the oxaloacetate/malate half reaction is -0.175 V. When the concentrations of NAD+, NADH, oxaloacetate, and malate are all 10-5 M, the "spontaneous" reaction is:
- A. NAD+ + oxaloacetate to NADH + H+ + malate
- B. NAD+ + NADH + H+ to malate + oxaloacetate
- C. malate + NADH + H+ to oxaloacetate + NAD+
- D. malate + NAD+ to oxaloacetate + NADH + H+
- E. oxaloacetate + NADH + H+ to malate + NAD+
6) The type of membrane transport that uses ion gradients as the energy source is:
- A. primary active transport
- B. simple diffusion
- C. secondary active transport
- D. passive transport
- E. facilitated diffusion
7) (2 pts) What is this compound? (structure from book)
- A. ubiquinone
- B. FAD
- C. the heme group of a cytochrome
- D. NADH
- E. cholesterol