Which of the following reaction is an example of substrate level phosphorylation occurring in TCA cycle?
In Krebs cycle, succinyl CoA is conveed to succinate by the enzyme succinate thiokinase. This is the only example of substrate level phosphorylation in the citric acid cycle. Substrate level phosphorylation is the biochemical process whereby ATP is produced from ADP through direct transfer of a high energy phosphoryl group from a reaction substrate to ADP. In glycolysis, substrate level phosphorylation occur during two reactions: Conversion of 1,3 BPG to 3 phosphoglycerate by phosphoglyerate kinase Conversion of phosphoenol pyruvate to pyruvate by pyruvate kinase. Ref: Bender D.A., Mayes P.A. (2011). Chapter 17. The Citric Acid Cycle: The Catabolism of Acetyl-CoA. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell (Eds), Harper's Illustrated Biochemistry, 29e.
Isocitrate to oxalosuccinate
Alpha keto glutarate to succinyl CoA
Succinyl CoA to succinate
Succinate to fumarate