In the Kreb’s cycle the FAD electron transport system operates during the conversion of

Options

(a) succinyl CoA to succinic acid
(b) alpha-ketoglutarate to succinyl CoA
(c) succinic acid to fumaric acid
(d) furmaric acid to malic acid

Correct Answer:

succinic acid to fumaric acid

Explanation:

Krebs cycle occurs in matric of mitochondria. In one of the steps in Krebs cycle or TCA cycle, succinic acid is oxidised to fumaric acid by the help of enzyme succinic acid dehydrogenase. In this step FAD takes up two hydrogen ions and the two electrons from succinic acid and get reduced.
Succinic acid + FAD ⇌ Fumaric acid + FADH₂.