Question

In aerobic respiration, first $C{O}_2$ is liberated during

• A. Oxidation of pyruvate
• B. Decarboxylation of oxalosuccinate
• C. Decarboxylation of $\alpha$-ketoglutarate
• D. Alcoholic fermentation

Answer 1

The correct option is A Oxidation of pyruvate

The pyruvic acid generated in the glycolysis enters into the mitochondrial matrix, undergoes oxidative decarboxylation and forms active acetate in a coordinated series of reactions catalyzed by the multienzyme complex. The reaction requires the participation of an enzyme pyruvate dehydrogenase and several coenzymes including NAD+, coenzyme A, thiamine pyrophosphate and lipoic acid. The above reaction involves the conversion of pyruvic acid to acetyl coenzyme A followed by the release of the first molecule of carbon dioxide.

Thus, the correct answer is option A.