Question

In Krebs cycle, $FA{D}^{+}$ is reduced to $FAD{H}_2$ during conversion of ________.

• A. succinyl CoA to succinate
• B. fumarate to malate
• C. $\alpha$-ketoglutarate to succinyl CoA
• D. succinate to fumarate

Answer 1

The correct option is D succinate to fumarate

In the Krebs cycle, $FA{D}^{+}$ is reduced to $FAD{H}_2$ during conversion of succinate to fumarate. During Krebs cycle, succinate is oxidized to fumarate in which $FA{D}^{+}$ precipitates as an electron acceptor. In this reaction, succinate is dehydrogenated by an enzyme succinate dehydrogenase. This enzyme removes two hydrogen ions and two electrons from succinate and are then transferred to $FA{D}^{+}$ which gets reduced to FADH${}_2$.

During conversion of succinyl coA to succinate, a molecule of GTP is formed.

During conversion of $\alpha$-ketoglutarate to succinyl CoA, NADH is produced.