Glyceraldehyde 3-phosphate, also known as triose phosphate or
3-phosphoglyceraldehyde and abbreviated as G3P, GA3P, GADP, GAP, TP, GALP or
PGAL, is a chemical compound that occurs as an intermediate in several central
metabolic pathways of all organisms. It is a phosphate ester of the 3-carbon
sugar glyceraldehyde and has chemical formula C3H7O6P.
The CAS number of glyceraldehyde 3-phosphate is 591-59-3 and that of
D-glyceraldehyde 3-phosphate is 591-57-1.
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, catalyzed by aldolase.
Compound C05378 at KEGG Pathway Database. Enzyme 4.1.2.13 at KEGG
Pathway Database. Compound C00111 at KEGG Pathway Database. Compound C00118
at KEGG Pathway Database. The numbering of the carbon atoms
indicates the fate of the carbons according to their position in fructose
6-phosphate. Dihydroxyacetone phosphate, catalyzed by
triose phosphate isomerase. Compound C00111 at KEGG Pathway
Database.Enzyme 5.3.1.1 at KEGG Pathway Database.Compound C00118 at KEGG Pathway
Database. 1,3-bisphosphoglycerate, catalyzed by
glyceraldehyde 3-phosphate dehydrogenase.
= As a substrate = To produce 1,3-bisphospho-D-glycerate in
glycolysis. Compound C00118 at KEGG Pathway
Database. Enzyme 1.2.1.12 at KEGG Pathway Database. Reaction R01063 at
KEGG Pathway Database. Compound C00236 at KEGG Pathway Database.
D-glyceraldehyde 3-phosphate is also of some importance since this is how
glycerol 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.
An intermediate in photosynthesis During plant photosynthesis, 2 molecules
of glycerate 3-phosphate are produced by the first step of the light-independent
reactions when ribulose 1,5-bisphosphate and carbon dioxide are catalysed by the
rubisco enzyme. The GP is converted to D-glyceraldehyde 3-phosphate using the
energy in ATP and the reducing power of NADPH as part of the Calvin cycle. This
returns ADP, phosphate ions Pi, and NADP+ to the light-dependent reactions
of photosynthesis for their continued function. RuBP is regenerated for the
Calvin cycle to continue. 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 →12 G3P 10 G3P → 6 RuBP
2 G3P → glucose. In tryptophan biosynthesis
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, another substance that cannot
be produced by the human body. References
External links D-Glyceraldehyde 3-phosphate and the
reactions and pathways it participates in, from the KEGG PATHWAY Database
Glyceraldehyde 3-phosphate and the reactions and pathways it participates
in, from the KEGG PATHWAY Database