21) A drug is tested in the laboratory and is found to create holes in both mitochondrial membranes. Scientists suspect that the drug will be harmful to human cells because it will inhibit
A) the citric acid cycle.
B) oxidative phosphorylation.
C) glycolysis.
D) the citric acid cycle and oxidative phosphorylation.
Answer: D
22) During which of the following phases of cellular respiration does substrate-level phosphorylation take place?
A) glycolysis
B) the citric acid cycle
C) oxidative phosphorylation
D) glycolysis and the citric acid cycle
ANswer: D
27) A culture of bacteria is fed glucose containing radioactive carbon and is then examined. As the bacteria metabolize the glucose, the radioactive carbon will appear first in
A) carbon dioxide.
B) glucose-6-phosphate.
C) pyruvate.
D) ATP.
Answer: B
32) The enzymes of the citric acid cycle are located in the
- A) cytoplasm.
- B) outer mitochondrial membrane.
- C) nucleus.
- D) matrix and inner mitochondrial membrane.
Answer: D
35) A culture of bacteria is fed glucose containing radioactive carbon and is then examined. During the citric acid cycle, radioactive carbon would first appear in
- A) NADH.
- B) citrate.
- C) oxaloacetate.
- D) CO2.
B
49) In fermentation, ________ is ________.
- A) NADH; reduced
- B) NAD+; oxidized
- C) NADH; oxidized
- D) ethanol; oxidized
C
50) When an organism such as a yeast lives by fermentation, it converts the pyruvate from glycolysis into a different compound, such as alcohol. Why doesn't it secrete the pyruvate directly?
- A) The conversion yields 32 ATP per pyruvate molecule.
- B) The conversion yields one NADH per pyruvate molecule.
- C) The conversion is needed to regenerate the molecules needed for glycolysis.
D) A buildup of pyruvate in the surrounding environment would be too tox
C