3- phosphoglycerate isomerization

A similar requirement for the phosphoglycerate isomerizing enzyme has been shown by Cori et Diphosphoglycerate is needed in catalytic amount for the reversible conversion of 3-p-glycerate to 2-p-glycerate. 

Step 8 is an isomerization between D-3-phosphoglycerate to D-2-phosphoglycerate. This is catalyzed by the enzyme phosphoglyceromutase. 

The enzyme phosphoglycerate kinase is involved, g Step 8 Isomerization. 

Isomerization of 3-phosphoglycerate then gives 2-phosphoglycerate in a step catalyzed by the enzyme phosphoglycerate mutase. The process involves formation of a 2,3-bisphosphoglycerate intermediate, followed by selective transfer of the 3-phosphate. 

C. Dihydroxyacetone phosphate (Compound I) is isomerized to glyceraldehyde 3-phosphate, which is oxidized to 1,3-bisphosphoglycerate in a reaction in which inorganic phosphate and NAD+ are utilized. Then 3-phosphoglycerate (Compound II) is formed and ATP is generated. 

Phosphoglycerate is isomerized to produce 2-phosphoglycerate in a reaction catalyzed by the enzyme phosphoglycerate mutase. The phosphoryl group attached to the third carbon of 3-phosphoglycerate is transferred to the second carbon. 

STEP 8 Isomerization of 3-phosphoglycerate gives 2-phosphoglycerate, 1 2-OjPO 0 1 II ... 

The trace amounts of 2,3 BPG found in cells other than erythrocytes is required for the phospho-glycerate mutase reaction of glycolysis, in which 3-phosphoglycerate is isomerized to 2-phosphoglycerate. As the 2,3 BPG is regenerated during each reaction cycle, it is only required in catalytic amounts. 

Step 8. Isomerization of 3-phosphoglycerate to give 2-phosphoglycerate. (See Equation 17.8, page 508.)... 

How is starting material regenerated in the Calvin cycle The remaining 10 molecules of 3-phosphoglycerate are used to regenerate the 6 molecules of ribulose-1, b-bisp o-sphate through a series of reactions that include reshuffling of carbon skeletons and isomerizations. 

The next reaction is the isomerization of 3-phosphoglycerate to 2-phosphoglycerate, catalyzed by phosphoglycerate mutase ... 

The Citric Acid Cycle (or the Tricarboxylic Acid [TCA] Cycle or the Krebsi Cycle). It will be recalled (Schemes 11.24-11.26) that the enzyme phosphoglycerate mutase (EC 5.4.2.1) acts on PGA (obtained from, e.g., fructose-1,6-bisphosphate) to produce the isomeric, 2-phosphoglycerate and that phosphopyruvate hydratase (EC 4.2.1.11) then converts the 2-phosphoglycerate to phosphoenolpyruvate. 

After the first transfer of phosphate described in 6, 3-phospho-glyceric acid is left. In the presence of phosphoglyceromutase and 2,3-diphosphoglyceric acid as coenzyme (see p. 175) an isomerization to 2-phosphoglyceric acid occurs. 

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