Question

In metabolism, which will come first:

Dephosphorylation of phosphoenolpyruvate (PEP) or dephosphorylation of 1,3 bisphosphoglycerate?

Please explain answer.

Answer 1

Dephosphorylation of 1,3- bisphosphoglycerate Comes first and results in the production of 3- phosphoglycerate and ATP, reaction is catalyzed by phosphoglycerate kinase. Now this 3-PGA will be converted to 2-PGA which in turn will be converted to PEP, then dephosphorylation of PEP will result in the production of pyruvate and ATP.

Preparatory phase (Energy investment phase) 6CH,OH Glucose, 6C - ATP Hexokinase, Mg2+ но з а он ADP CH OP Glucose-6-phosphate, 6C HO он Phosphoglucoisomerase 2 POH,C6 1CH OH Fructose-6-phosphate, 6C OH ATP Phosphofructokinase-1, Mg2+ ADP POHC CH OP Fructose-1,6-bisphosphate, 6C ОН Aldolase, Zn2+ Glyceraldehyde-3-phosphate, 30 Dihydroxyacetone phosphate, 3C = Glyceraldehyde-3-phosphate, 30 Triose phosphate он isomerase HOHC-C- CH OP POHẠC–CH–CHO ОН Payoff phase (Energy generation) 2 x Glyceraldehyde-3-phosphate, 30 POHC-CH- CHO Glyceraldehyde-3-phosphate dehydrogenase 2NAD + 2HPO- 2NADH + 2H+ 5-5 0= 2 X 1,3-bisphosphoglycerate, 3C POH,C-CH-C OP 2 ADP Phosphoglycerate kinase Substrate level phosphorylation 2 x 2,3-BPG 2 ATP 5-7 o=0 2 x 3-phosphoglycerate, 3C - POH,C-CH- C- 0 Phosphoglycerate mutase mutase 1. OP O=0 2 x 2-phosphoglycerate, 30 HOH,C-CH- - 0- Enolase, Mg2+ or Mn2+ 2H2O OP о 2 x Phosphoenolpyruvate, 3C H,C= C- C- 0 -2 ADP Pyruvate kinase, Mg2+, K+ Substrate level phosphorylation * 2 ATP 2 x Pyruvate, 3c O=0 HC_8_8_o HỌC C