Q. which of these steps in Krebs’ cycle indicates substrated level phosphorylation ?

A. Conversion of succinic acid to a-ketoglutaric acid

B. Conversion of succinic acid to malic acid

C. Conversion of succinyl CoA to succinic acid

D. Conversion of malic acid to oxaloacetic acid

Correct Answer : Option C

Solution

The correct option is C Conversion of succinyl Co-A to succinic acid
During the conversion of Succinyl Co-A to Succinic acid, a molecule of GTP is synthesized. This is a substrate level phosphorylation. In a coupled reaction, GTP is converted to GDP with the simultaneous synthesis of ATP from ADP.