mannose to fructose-6-phosphate catabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways in which mannose, the aldohexose manno-hexose, is converted to fructose-6-phosphate. [GOC:dph, ISBN:0201090910, ISBN:0879010479]

The mannose to fructose-6-phosphate catabolic process is an important pathway in carbohydrate metabolism, specifically for the utilization of mannose, a hexose sugar. This process takes place in the cytoplasm of cells and involves a series of enzymatic reactions that convert mannose into fructose-6-phosphate, a crucial intermediate in glycolysis. Here's a detailed description:

**1. Mannose Phosphorylation:**
The first step involves the phosphorylation of mannose by the enzyme hexokinase, which utilizes ATP to add a phosphate group to the 6th carbon of mannose, forming mannose-6-phosphate.

**2. Isomerization to Fructose-6-phosphate:**
The resulting mannose-6-phosphate undergoes an isomerization reaction catalyzed by the enzyme phosphomannose isomerase. This enzyme converts mannose-6-phosphate into fructose-6-phosphate. The reaction involves an intramolecular shift of the hydroxyl group from the C2 to the C1 position, effectively transforming the aldose structure of mannose-6-phosphate into the ketose structure of fructose-6-phosphate.

**3. Entry into Glycolysis:**
Once fructose-6-phosphate is formed, it readily enters the glycolytic pathway, the central metabolic pathway for the breakdown of glucose. From this point onwards, fructose-6-phosphate follows the same steps as other hexose sugars in glycolysis, eventually generating ATP and reducing equivalents in the form of NADH.

**Overall, the mannose to fructose-6-phosphate catabolic process enables cells to utilize mannose as a source of energy and metabolic intermediates, contributing to the overall energy balance of the organism.**'
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Proteins (1)

Compounds (10)