pentose phosphate pathwaymedical dictionary

<biochemistry> A pathway of hexose oxidation in which glucose-6-phosphate undergoes two successive oxidations by NADP, the final one being an oxidative decarboxylation to form a pentose phosphate.

Diverges from this when glucose-6-phosphate is oxidized to ribose 5 phosphate by the enzyme glucose-6 phosphate dehydrogenase. This step reduces NADP to NADPH, generating a source of reducing power in cells for use in reductive biosyntheses.

In plants, part of the pathway functions in the formation of hexoses from carbon dioxide in photosynthesis. Also important as source of pentoses, for example for nucleic acid biosynthesis. This pathway is the main metabolic pathway in neutrophils, congenital deficiency in the pathway produces sensitivity to infection.

Alternative metabolic route to Embden Meyerhof pathway for breakdown of glucose.

This entry appears with permission from the Dictionary of Cell and Molecular Biology

(11 Mar 2008)