A. Select the correct response.
1. All cells undergo glycolysis.
2. NAD is a coenzyme that is readily oxidized and reduced, and acts as a hydrogen (electron) carrier.
3. The site of glycolysis is the mitochondrial matrix.
4. The raw materials for glycolysis are glucose and oxygen.
5. For the decarboxylation of one molecule of pyruvic acid to acetyl-coenzyme A, there is no net production of NADH.
6. The oxidation of one molecule of glucose gives rise to one glycolytic process and two citric acid cycles.
7. Three molecules of ATP can be harvested for every molecule of FADH.
8. Fermentation occurs because glycolysis is no longer in operation.
9. In animal fermentation, muscle cells use lactate dehydrogenase to add the hydrogen of the NADH produced by glycolysis back to the pyruvic acid, converting the latter into lactic acid and NADH into NAD.
10. Cytochromes are proteins composed of complex carbon rings and bear resemblance to heme.
11. The reaction sequence of the citric acid cycle:
Acetyl-CoA + Oxaloacetic acid -> alpha-ketoglutaric acid -> Malic acid -> Succinic acid -> Oxaloacetic acid
12. Cytochrome oxidase, which reduces the oxygen to form water at the end of the electron transport chain, is inhibited by cyanide.
13. Oxygen is necessary for accepting electrons as well as for the formation of carbon dioxide in the citric acid cycle.
14. Cellular respiration is regulated by feedback inhibition; the overabundance of ATP acts to shut off key respiratory enzymes used in glycolysis and the citric acid cycle.
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