glucose metabolism

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Process through which glucose is oxidized to carbon dioxide and water as a metabolic fuel (i.e. to provide energy). The overall reaction is:

C6H12O6 + 6O2 → 6CO2 + 6H2O

, occurring in a series of stages. The oxidation of glucose to carbon dioxide and water yields 16.4 kJ (3.9 kcal)/g; 2.88 MJ (686 kcal)/mol.

The first series of reactions does not require oxygen and is referred to as (anaerobic) glycolysis or glucose fermentation, yielding two molecules of the three-carbon compound pyruvic acid. Under anaerobic conditions this can be reduced to lactic acid.

Pyruvic acid is normally oxidized to acetyl CoA, which is then oxidized to carbon dioxide and water in a series of reactions known as the citric acid cycle. Both glycolysis and the citric acid cycle are linked to the formation of ATP from ADP and phosphate, as a metabolically usable energy source.

Subjects: Medicine and Health.

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