Question

Conversion of pyruvate to acetyl CoA is catalyzed by ___________________; this reaction is highly energetically favorable and ____________ A) Acetyl CoA dehydrogenase, reversible B) pyruvate dehydrogenase, reversible C) Acetyl CoA dehydrogenase, irreversible D) pyruvate dehydrogenese, irreversible

Answer 1

Conversion of pyruvate to acetyl CoA is catalyzed by pyruvate dehydrogenase complex; this reaction is highly energetically favorable and irreversible. (C)

Step-by-step explanation:

The conversion of pyruvate to acetyl CoA is catalyzed by pyruvate dehydrogenase and this reaction is irreversible. In the transition reaction, pyruvate dehydrogenase removes a carboxyl group from pyruvate, producing carbon dioxide. Then, dihydrolipoyl transacetylase oxidizes a hydroxyethyl group to an acetyl group, producing NADH. Lastly, an enzyme-bound acetyl group is transferred to CoA, producing a molecule of acetyl-CoA.

Overall, the conversion of pyruvate to acetyl CoA is an important step in cellular respiration and occurs in the mitochondrial matrix.