Triose Phosphate Isomerase (TIM) uses acid/base catalysis to move the carbonyl from C2 to C1

GAP dehydrogenase oxidizes an aldehyde to thioester and then displaces with phosphate to make a high

energy phosphoanhydride

An aldehyde cannot be oxidized by hydride transfer, but a thiohemiacetal can. The product thioester captures some of the energy of oxidation in the high energy C-S bond.

GAP dehydrogenase oxidizes an aldehyde to thioester and then displaces with phosphate to make a high

energy phosphoanhydride

The thioester is sufficiently reactive that even a poor nucleophile such as a phosphate ion can react and displace the catalytic cysteine residue.

Phosphoglycerate kinase is a reversible phosphoryl transfer to ADP

The energy of the phosphoanhydride bond can be captured by transferring the phosphate to ADP, generating an equally high energy phosphodiester bond

3-Phosphoglycerate mutase moves a phosphate through “sleight of hand”

How does the first phosphate get on the enzyme?

How stable do you think a phosphohistidine bond is?

Enolase generates the high energy phosporylated enolate phosphoenolpyruvate

Two Mg2+ ions help to stabilize negative charge through electrostatic attractions

Deprotonation of the C position leads to an elimination of water by a E1cB mechanism

PEP is a very high energy phosphate ester because the enolate leaving group can immediately isomerize to a ketone