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
• E. Oxaloacetic acid to citric acid

Answer 1

Answer: (B)

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. $FAD{H}_2$ (reduced flavin adenine dinucleotide) is produced.
Succenate $+FAD\stackrel{\stackrel{\text{Succinate}}{\mathrm{dehydrogenase}}}{\to }$ Fumarate $+FAD{H}_2$