question for oxidative phosphorylation

1. Which of the following is true about the difference between oxidative phosphorylation and photophosphorylation?
A. Photophosphorylation occurs only in photosynthetic organisms and oxidative phosphorylation occurs only in non-photosynthetic organisms.
B. In oxidative phosphorylation, NADH donates electrons; in photophosphorylation NADPH donates electrons.
C. Photophosphorylation occurs only in light; oxidative phosphorylation occurs only in darkness.
D. In oxidative phosphorylation, O2 is reduced to H2O; in photophosphorylation, H2O is oxidized to O2.


2. Which of the following processes takes place in the mitochondrial matrix?
A. cellular respiration
B. glycolysis
C. fatty acid oxidation
D. photosynthesis


3. Which of the following is true about the expression of mitochondrial genes?
A. Mitochondria encode all of the proteins needed to make new mitochondria.
B. Mitochondria can translate their own genes.
C. Mitochondria import all of their proteins from the cytoplasm.
D. Mitochondrially-encoded genes are expressed in the cytoplasm.


4. Diseases caused by mutations in mitochondrial genes are invariably inherited from the mother because
A. mitochondrial genes are encoded on the X chromosome.
B. males do not have mitochondrial DNA.
C. all of the mitochondria of a developing embryo are derived from the mother's egg.
D. mitochondrial genes of males are turned off.


5. How do mitochondria eliminate the harmful superoxide free radical ·O2- that is generated with low frequency during oxidative phosphorylation?
A. Glutathione reductase reduces ·O2- to H2O.
B. Superoxide dismutase converts ·O2- to H2O2.
C. Glutathione peroxidase converts ·O2- to O2.
D. ·O2- is transported out of mitochondria.


6. Which of the following processes yields the greatest number of ATP molecules when a molecule of glucose is completely oxidized?
A. lactate fermentation
B. pyruvate oxidation
C. glycolysis
D. the citric acid cycle


7. How does thermogenin keep newborn mammals warm?
A. It makes oxidative phosphorylation more efficient.
B. It causes the transfer of electrons from ubiquinone directly to oxygen.
C. It uncouples electron transport from ATP synthesis.
D. It stimulates the accumulation of brown fat.


8. The light-dependent and carbon-assimilation reactions of photosynthesis are linked in that
A. the light-dependent reactions generate the chemical energy needed for carbon-assimilation.
B. the oxidation of carbohydrates from the carbon-assimilation reactions drives the synthesis of ATP in the light-dependent reactions.
C. carbon dioxide generated in the light-driven reactions is converted to triose phosphates in the carbon-assimilation reactions.
D. NADPH generated in the carbon-assimilation reactions drives the synthesis of ATP in the light-dependent reactions.


9. In which part of the chloroplast do the light-dependent reactions of photosynthesis take place?
A. in the thylakoid lumen
B. in the thylakoid membrane
C. in the stroma
D. in the inner membrane


10. What is the role of antenna molecules in photosynthesis?
A. to donate their electrons for use in oxidation-reduction reactions
B. to release absorbed energy as fluorescence
C. to transmit light energy to reaction centers
D. to transduce light energy into chemical energy


11. The F0 complex of mitochondrial ATP synthase
A. is inhibited by oligomycin.
B. synthesizes ATP.
C. pumps protons into the mitochondrial matrix.
D. is a peripheral membrane protein.


12. Which complex of the respiratory chain is inhibited by cyanide?
A. Complex IV
B. ATP synthase
C. Complex I
D. Complex III


13. How will oxidative phosphorylation be affected by placing intact mitochondria in a weak acid that can readily diffuse across the mitochondrial membranes?
A. Electron transfer reactions will be inhibited.
B. No H2O will be generated.
C. ATP will be able to be synthesized in the absence of an oxidizable substrate.
D. ATP synthesis will be inhibited.


14. Complexes I and II of the mitochondrial respiratory chain
A. have heme prosthetic groups.
B. transfer electrons directly to ubiquinone.
C. pump protons from the matrix to the intermembrane space.
D. transfer electrons from NADH.


15. How does NADH generated by glycolysis in the cytosol get conveyed into mitochondria for oxidation in the respiratory chain?
A. It diffuses through the inner mitochondrial membrane.
B. Its reducing equivalents are transported across the inner mitochondrial membrane.
C. It is transported across the inner mitochondrial membrane as aspartate.
D. It is transported directly across the inner mitochondrial membrane by an NADH transporter.


sources: http://bcs.whfreeman.com/lehninger/pages/bcs-main.asp?v=chapter&i=19070.01&s=19000&n=00070&o=|00510|00520|0

Lehninger Principles of Biochemistry