Dihydroxyacetone phosphate

Dihydroxyacetone phosphate (DHAP) is a biochemical compound involved in many reactions, from the Calvin cycle in plants to the ether-lipid biosynthesis process in Leishmania mexicana. Its major biochemical role is in the glycolysis metabolic pathway. DHAP may be referred to as glycerone phosphate in older texts.

Dihydroxyacetone phosphate in glycolysis
Dihydroxyacetone phosphate lies in the glycolysis metabolic pathway, and is one of the two products of breakdown of fructose 1,6-bisphosphate, along with glyceraldehyde 3-phosphate. It is rapidly and reversibly isomerised to glyceraldehyde 3-phosphate.

The numbering of the carbon atoms indicates the fate of the carbons according to their position in fructose 6-phosphate.

Dihydroxyacetone phosphate in other pathways
In the Calvin cycle, DHAP is one of the products of the sixfold reduction of 1,3-bisphosphoglycerate by NADPH. It is also used in the synthesis of sedoheptulose 1,7-bisphosphate and fructose 1,6-bisphosphate, both of which are used to reform ribulose 5-phosphate, the 'key' carbohydrate of the Calvin cycle.

DHAP is also the product of the dehydrogenation of L-glycerol-3-phosphate, which is part of the entry of glycerol (sourced from triglycerides) into the glycolytic pathway. On the converse, reduction of glycolysis-derived DHAP to L-glycerol-3-phosphate provides adipose cells with the activated glycerol backbone they require to synthesize new triglycerides. Both reactions are catalyzed by the enzyme glycerol 3-phosphate dehydrogenase with NAD+/NADH as cofactor.