Question

Conversion of phosphoglyceraldehyde to 1, 3- biphosphogly eerie acid is a

• A. priming reaction only
• B. redox reaction only
• C. priming and redox reaction only
• D. substrate level phosphorylation reaction.

Answer 1

Answer: (D)

: During the glycolytic pathway (dehydrogenation and phosphorylation), in the presence of enzyme glyceraldehyde phosphate dehydrogenase, glyceraldehyde 3-phosphate loses hydrogen to NAD to from $NAD{H}_2$ and accepts inorganic phosphate to form $1:3$ diphosphoglycerate. Glyceraldehyde 3 - phosphate $+H_{3}P{O}_4+NA{D}^{+}$ $1:3$ phosphoglycerate $+NADH+H^{+}$ One of the two phosphates of diphos-phoglycerate is linked by high energy bond. It can synthesis ATP and form 3-phosphoglycerate by using the enzyme phosphoglycerate kinase. The direct synthesis of ATP from metabolites is called substrate level phosphorylation. $1:3$ diphosphoglycerat $+ADP$ 3 - phosphoglycerate + ATP.