Английская Википедия:Glyceraldehyde 3-phosphate
Шаблон:Distinguish Шаблон:Chembox 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.[1][2] 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:
Шаблон:Complex enzymatic reaction Шаблон:KEGG compound Шаблон:KEGG enzyme Шаблон:KEGG compound Шаблон:KEGG compound
The numbering of the carbon atoms indicates the fate of the carbons according to their position in fructose 6-phosphate.
- Dihydroxyacetone phosphate (DHAP), catalyzed by triose phosphate isomerase.
Шаблон:Enzymatic Reaction Шаблон:KEGG compoundШаблон:KEGG enzymeШаблон:KEGG compound
- 1,3-bisphosphoglycerate (1,3BPG), catalyzed by glyceraldehyde 3-phosphate dehydrogenase.
As a substrate
- To produce 1,3-bisphospho-D-glycerate in glycolysis.
Шаблон:Enzymatic Reaction Шаблон:KEGG compound Шаблон:KEGG enzyme Шаблон:KEGG reaction Шаблон:KEGG compound
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
|Шаблон:GlycolysisGluconeogenesis WP534
An intermediate in photosynthesis
During plant photosynthesis, 2 equivalents of glycerate 3-phosphate (GP; also known as 3-phosphoglycerate) are produced by the first step of the light-independent reactions when ribulose 1,5-bisphosphate (RuBP) and carbon dioxide are catalysed by the rubisco enzyme. The GP is converted to D-glyceraldehyde 3-phosphate (G3P) 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 (+ energy from 12 ATP and 12 NADPH) →12 G3P (3-carbon)
10 G3P (+ energy from 6 ATP) → 6 RuBP (i.e. starting material regenerated)
2 G3P → glucose (6-carbon).
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 (Vitamin B1), 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
Шаблон:Glycolysis Шаблон:Fructose and galactose metabolic intermediates
- ↑ Шаблон:Cite book
- ↑ Nelson, D. L.; Cox, M. M. "Lehninger, Principles of Biochemistry" 3rd Ed. Worth Publishing: New York, 2000. Шаблон:ISBN.
