Ribose 5-phosphate
- 3615-55-2 ( ribose-5- phosphoric acid)
- 4300-28-1 (D -ribose -5-phosphate )
- 93-87-8 (D - ribofuranose 5-phosphate )
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Ribose -5-phosphate is a natural pentose, which is an intermediate product and the pentose phosphate pathway (PPP ) is formed. As with many other carbohydrate metabolism is of the two enantiomers, only the D- form of importance.
Production in the pentose phosphate pathway
Depending on the metabolic situation of the cell requires these different metabolic products, which is reflected in the practices of metabolic pathways. Thus picked D-glucose is phosphorylated in the cell in order to prepare for the reduction; Thus, there is produced D-glucose -6-phosphate. This is now mostly dismantled for the purpose of ATP production glycolysis to pyruvate, bacteria and archaea, glucose -6-phosphate in the Entner- Doudoroff pathway to metabolize.
An alternative pathway is the pentose phosphate pathway (PPP). The glucose -6-phosphate is thereby oxidized and decarboxylated directly: In the oxidative part of the PPP is generated at twice the oxidation of glucose -6-phosphate to 6 - Phosphoglucono - δ - lactone, and 6-phosphogluconate NADPH. 6-phosphogluconate is then decarboxylated to ribulose -5-phosphate, which is ultimately isomerized by Phosphopentoseisomerase to ribose - 5-phosphate. In the non- oxidative part are formed by rearrangement reactions metabolic intermediates of carbohydrate metabolism.
Importance in the metabolism
Ribose -5 -phosphate, plays an important role in the synthesis of nucleotides, coenzymes, and amino acids.
The nucleotide is from ribose -5-phosphate by the reaction with ATP in. 5-phosphoribosyl - 1-pyrophosphate ( PRPP ) ( and AMP ) are formed. In the pyrimidine biosynthesis, the already completed synthesized pyrimidine ring is attached to the PRPP molecule, whereas the purine ring at the PRPP is synthesized.
In the amino acid biosynthesis synthesized from ribose -5 -phosphate, PRPP is required, for example, for the carbon backbone of histidine. Ribose -5-phosphate is also a component of coenzymes, such as NADH and FAD.