Question

FAD is electron acceptor in the citric acid cycle during the oxidation of

• A. Malic acid to oxaloacetic acid
• B. Succinic acid to malic acid
• C. Citric acid to alpha-ketoglutaric acid
• D. Alpha-ketoglutaric acid to succinic acid

Answer 1

Answer: (B)

Succinic acid to malic acid

Answer 2

In the citric acid cycle, FAD is electron acceptor during oxidation of succinate. Succinate undergoes dehydrogenation to form fumarate with the help of membrane based enzyme succinate dehydrogenase. $FADH_2$ (reduced flavin adenine dinucleotide) is produced.
Succenate $+ FAD {->[{\overset{\text{Succinate}}{\text{dehydrogenase}}}]}$ Fumarate $+ FADH_2$