Question

Oxidation of pyruvate is accompanied by

• A. Oxidation of $NA{D}^{+}$
• B. Reduction of $NA{D}^{+}$
• C. Oxidation of CoA
• D. Reduction of CoA

Answer 1

Answer: (B)

Reduction of $NA{D}^{+}$

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 catalysed by multienzyme complex. The reaction requires participation of an enzyme pyruvate dehydrogenase and several coenzymes including NAD+, coenzyme A, thiamine pyrophosphate and lipoic acid. The above equation occurs in 4 steps involving conversion of pyruvic acid to acetyl coenzyme A. One molecule of carbon dioxide is released. The coenzyme NAD+ is reduced to NADH + H+ in the reaction. The acetyl coenzyme A is accepted by Kreb's cycle.

Thus, the correct answer is option B.