glucose 6-phosphate metabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways involving glucose 6-phosphate, a monophosphorylated derivative of glucose with the phosphate group attached to C-6. [GOC:ai]

Glucose 6-phosphate (G6P) is a pivotal intermediate in carbohydrate metabolism, playing a central role in both glycolysis and gluconeogenesis. The metabolic processes involving G6P are intricate and encompass a wide range of biochemical reactions.

**Glycolysis:** G6P is generated from glucose via the action of hexokinase or glucokinase. This step is the first committed step in glycolysis, the breakdown of glucose to pyruvate, generating ATP. G6P then undergoes a series of enzymatic reactions, including isomerization to fructose 6-phosphate, phosphorylation to fructose 1,6-bisphosphate, and cleavage to glyceraldehyde 3-phosphate and dihydroxyacetone phosphate. The subsequent reactions ultimately yield pyruvate, a key substrate for further energy production in the citric acid cycle.

**Gluconeogenesis:** This process is the synthesis of glucose from non-carbohydrate precursors, such as pyruvate, lactate, and amino acids. G6P serves as an essential intermediate in this pathway. Gluconeogenesis reverses many of the steps in glycolysis, but key regulatory enzymes differ. G6P is formed from fructose 1,6-bisphosphate by the action of fructose 1,6-bisphosphatase.

**Pentose Phosphate Pathway (PPP):** This pathway provides reducing power in the form of NADPH, essential for biosynthesis and detoxification processes. G6P is the starting point for the PPP, where it is oxidized to 6-phosphogluconate. This pathway also generates ribose 5-phosphate, a precursor for nucleotide biosynthesis.

**Glycogen Metabolism:** G6P is a key intermediate in glycogen synthesis and breakdown. Glucose is first phosphorylated to G6P before it can be incorporated into glycogen. During glycogenolysis, glycogen is broken down to G6P, which can then enter glycolysis or be used for other metabolic processes.

**Other Metabolic Roles:** G6P can also be used for the synthesis of other important molecules, including:

* **Glycerol 3-phosphate:** A precursor for triglyceride synthesis.
* **Amino acids:** G6P can be converted to glucose 6-phosphate, which can then be used for amino acid biosynthesis.

The intricate network of G6P metabolic processes is tightly regulated, ensuring a constant supply of energy and essential building blocks for cellular functions.'
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Proteins (3)

Compounds (32)