Glucose 6-phosphate
- Robinson - ester
- G -6-P
- 56-73-5
- 5996-17-8 ( dipotassium salt )
Risk
Template: Infobox chemical / molecular formula search available
Glucose -6-phosphate (synonyms: Robison ester; G -6-P ) is an organic molecule that plays an important role in the metabolism of almost all living things. It consists of a glucose molecule ( glucose ), at the sixth carbon atom, a phosphate group is attached. The normal content of glucose -6-phosphate in the erythrocytes is 39 to 127 mol / L.
Importance
Glucose -6-phosphate is an important metabolite in the cell metabolism. It is produced during glycolysis from glucose with the consumption of ATP.
Hexokinase reaction
Is catalyzed by the enzyme hexokinase I-IV. The reaction is with ΔG0 '= -13.7 kJ / mol under standard conditions exergonic and irreversible. Under physiological conditions, for example in the course of glycolysis is? G = -33.9 kJ / mol.
By this reaction, glucose is "activated", in other words converted into a higher energy molecule. The amount of energy used therein is released again later in the following reaction steps.
In the next step of glycolysis is glucose -6-phosphate is isomerized to fructose -6-phosphate. The enzyme that catalyzes this reaction, the glucose-6 -phosphate isomerase.
Further reactions
1 glucose -6-phosphate being oxidized by the enzyme glucose-6 -phosphate dehydrogenase to give 6- phosphogluconolactone within the pentose. It arises for the fatty acid and steroid biosynthesis required NADPH. The metabolic disorder of glucose -6-phosphate dehydrogenase deficiency is widespread in Central Africa.
2 In the context of glycogen is converted into glucose -1-phosphate, glucose-6 -phosphate. This reaction is catalyzed by the enzyme glucose -6-phosphate mutase. The glucose-1- phosphate can then be linked to " animal starch " ( glycogen), what happens in humans in the liver.
3 is formed in the gluconeogenesis, glucose-6 -phosphate from fructose -6-phosphate by phosphohexose isomerase reaction. In skeletal muscle glucose -6-phosphate, the final product of glycogenolysis. In the endoplasmic reticulum of the liver and kidneys can be cleaved by the enzyme glucose -6-phosphatase to glucose, glucose-6 -phosphate. A defect in the glucose-6- phosphatase leads to by - Gierke disease type Ia.