Sunday, June 12, 2011

Second Half of Glycolysis

The last five reactions of glycolysis leads to production of two pyruvate molecules.  The last five reactions are called the energy harvesting or energy payoff phase.

Reaction 6:  Glyceraldehyde-P  Dehydrogenase Reaction
G3P is converted to 1, 3 bisphosphoglycerate

This is the first reaction in glycolysis to generate a NADH molecule.  NADH is an electron carrier that is used in the mitochondrion by the ETC to generate ATP.

Reaction 7:  Phosphoglycerate kinase converts 1,3 BPG to 3-phosphoglycerate.  It is the first step of glycolysis to generate ATP via substrate level phosphorylation.  A phosphate group is removed from 1,3 BPG and transferred to ADP to form ATP (substrate-level phosphorylation).

Reaction 8:  Phosphoglycerate mutase converts 3-phosphoglycerate to 2-phosphoglycerate. 

What is the purpose of this reaction?
This rearrangement of the phosphate from the C-3 to C-2 position allows productio of phosphoenolpyruvate in the next reaction.

Reaction 9:  Enolase converts 2-PG to PEP

Reaction 10:  Pyruvate kinase converts PEP to pyruvate and also generates ATP via substrate level phosphorylation.

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