In which of the following steps of the TCA cycle does Substrate level phosphorylation occurs?
Succinyl-CoA is conveed to succinate by the enzyme succinate thiokinase or also called as succinyl-CoA synthetase. GTP formation takes place in this step, and hence this is the one and only example of substrate level phosphorylation in the TCA cycle. The GTP so formed is used for the decarboxylation of oxaloacetate to phosphoenolpyruvate in gluconeogenesis. Here GTP is equivalent to ATP. Reference: 1. Harper's Illustrated Biochemistry 31st edition Pg 153
Succinate to fumarate
Isocitrate to alpha keto glutarate
Alpha keto glutarate to succinyl CoA
Succinyl CoA to Succinate
Metabolism of carbohydrate