Dihydroxyacetone phosphate (DHAP, also glycerone phosphate in older texts) is the anion with the formula HOCH
2C(O)CH
2OPO
32-. This anion is involved in many
metabolic pathway
In biochemistry, a metabolic pathway is a linked series of chemical reactions occurring within a cell (biology), cell. The reactants, products, and Metabolic intermediate, intermediates of an enzymatic reaction are known as metabolites, which are ...
s, including the
Calvin cycle
The Calvin cycle, light-independent reactions, bio synthetic phase, dark reactions, or photosynthetic carbon reduction (PCR) cycle of photosynthesis is a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into ...
in plants and
glycolysis
Glycolysis is the metabolic pathway that converts glucose () into pyruvic acid, pyruvate and, in most organisms, occurs in the liquid part of cells (the cytosol). The Thermodynamic free energy, free energy released in this process is used to form ...
.
[Nelson, D. L.; Cox, M. M. "Lehninger, Principles of Biochemistry" 3rd Ed. Worth Publishing: New York, 2000. .] It is the
phosphate ester of
dihydroxyacetone.
Role 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
Glyceraldehyde 3-phosphate, also known as triose phosphate or 3-phosphoglyceraldehyde and abbreviated as G3P, GA3P, GADP, GAP, TP, GALP or PGAL, is a metabolite that occurs as an intermediate in several central pathways of all organisms.Nelson, D ...
. 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.''
Role in other pathways
In the
Calvin cycle
The Calvin cycle, light-independent reactions, bio synthetic phase, dark reactions, or photosynthetic carbon reduction (PCR) cycle of photosynthesis is a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into ...
, 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
Glycerol () is a simple triol compound. It is a colorless, odorless, sweet-tasting, viscous liquid. The glycerol backbone is found in lipids known as glycerides. It is also widely used as a sweetener in the food industry and as a humectant in pha ...
(sourced from
triglycerides
A triglyceride (from ''wikt:tri-#Prefix, tri-'' and ''glyceride''; also TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids.
Triglycerides are the main constituents of body fat in humans and oth ...
) into the
glycolytic pathway. Conversely, 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.
DHAP also has a role in the
ether-lipid biosynthesis process in the protozoan parasite ''
Leishmania mexicana''.
DHAP is a precursor to
2-oxopropanal. This conversion is the basis of a potential biotechnological route to the commodity chemical
1,2-propanediol.
See also
*
Dihydroxyacetone
*
Glycerol 3-phosphate shuttle
References
{{Glycolysis
Photosynthesis
Alpha-hydroxy ketones
Organophosphates
Phosphate esters
Glycolysis
Biomolecules
Metabolic intermediates