Oxidation of glyceraldehyde-3-phosphate

Oxidation of glyceraldehyde-3-phosphate: The  conversion  of glceraldehyde- 3-phosphate to  1,3-bisphosphoglycerate  is catalysed  by  glyceraldehyde- 3-phosphate dehydrogenase  and the required cofactors are NAD'  and Pi. The NADH formed is reoxidized  either via the respiratory chain or by  the NADH linked coilversion of  pyruvate  to lactate. The  high-energy phosphate group at carbon 1  of  1,3-bisphosphoglycerate conserves much of  the free energy produced by the oxidation of glyceraldehyde-3-phosphate. This is an example of substrate level pllosphorylation in which the production of a high-energy phosphate is coupled directly  to  the  oxidation  of a  substrate  instead  of resulting-from oxidative plosphorylation  via the election transport chain.