ATP produced during glycolysis is a result of substrate level phosphorylation. Explain.
Substrate-level Phosphorylation is a type of metabolic reaction that results in the formation of Adenosine Triphosphate (ATP) or Guanosine Triphosphate (GTP) by the direct transfer and donation of a phosphoryl (PO3) group to Adenosine Diphosphate (ADP) or Guanosine Diphosphate (GDP) from a phosphorylated reactive intermediate.
In glycolysis substrate level phosphorylation occurs in following two reactions
(i) 2 molecules of 1,3 -diphosphoglyceric acid react with 2 molecules of ADP to form 2 molecules of 3 -phosphoglyceric acid and 2 molecules of ATP.
(ii) 2 molecules of phosphoenolpyruvic acid reacts with 2 molecules of ADP to form 2 molecules of pyruvic acid and 2 ATP.