Question

Identify the type of high energy bond in the intermediate of the glyceraldehyde-3-phosphate dehydrogenase reaction. What is the importance of this bond for the energetics of the reaction? L a nthus are regulated? How are they regualted

Answer 1

In reaction of glyceraldehyde-3-phosphate dehydrogenase(G-3-P):- During the reaction of G-3-P undergo oxidation and phosphorlyation. The product, glycerate-1,3-bisphoshate, contain a high energy phosphoanhydride bond, which used in the next reaction to generate ATP,

Glycerate-1,3-bisphosphate is catalyzed by G-3-P dehydrogenase, a tetramer composed by four identical subunits. Each subunit contains one binding site for G-3-P and another for NAD, an oxidizing agent. As an enzyme form a covalent thoether bond with substrate, a hydride ion id transferred to NAD⁺, then leave the active site. NADH, the reduced form of NAD⁺, then leave the active site and is replaced by an incoming NAD⁺.

Synthesis of ATP : In This reaction ATP synthesized as phosphoglycerate kinase catalyst the transfer of the high energy phosphoryl group of glycerate-1,3-bisphosphate to ADP .

A substrate level phosphorylation. because the synthesis of ATP is endoergonic, it required an energy source. ATP is produced by transfer of a phosphoryl group from a substrate with high phosphoryl transfer potential( glycerate-1,3-bisphosphate)to produced a compound with lower transfer potential(ATP) .
Date Page No. - P- 5 lett + NAD H + NADt + Pi = 1 C-OH o active benve 1 He-ow on CH₂-O-P-o site C4-o- p- o. High energy bond Glyce rate-1,3-bisphosphate NADH + 14 +

NADH - H C-o- P-0 HacoH coh TNAD + Pi H — cooh out Cty-o- Hoo- p. -0 Glycerate-1,3-bis- - Phosphate (Intermediate) ADP Mgh @EU-u. HC OH CH2-O- p- o Glycerate-3-phosphate ATP.