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.[2][3] With the chemical formula H(O)CCH(OH)CH2OPO32-, this anion is a monophosphate ester of glyceraldehyde.
An intermediate in both glycolysis and gluconeogenesis
Formation
D-glyceraldehyde 3-phosphate is formed from the following three compounds in reversible reactions:
Fructose-1,6-bisphosphate (F1,6BP), catalyzed by aldolase.
D-glyceraldehyde 3-phosphate is also of some importance since this is how glycerol (as DHAP) enters the glycolytic and gluconeogenic pathways. Furthermore, it is a participant in and a product of the pentose phosphate pathway.
Interactive pathway map
|Click on genes, proteins and metabolites below to link to respective articles.[§ 1]
G3P is generally considered the prime end-product of photosynthesis and it can be used as an immediate food nutrient, combined and rearranged to form monosaccharide sugars, such as glucose, which can be transported to other cells, or packaged for storage as insoluble polysaccharides such as starch.
Balance sheet
6 CO2 + 6 RuBP (+ energy from 12 ATP and 12 NADPH) →12 G3P (3-carbon)
10 G3P (+ energy from 6 ATP) → 6 RuBP (i.e. starting material regenerated)
Glyceraldehyde 3-phosphate occurs as a byproduct in the biosynthesis pathway of tryptophan, an essential amino acid that cannot be produced by the human body.
In thiamine biosynthesis
Glyceraldehyde 3-phosphate occurs as a reactant in the biosynthesis pathway of thiamine (Vitamin B1), another substance that cannot be produced by the human body.