pentose phosphate pathway

(phosphogluconate pathway, hexose monophosphate shunt) A complex multifunctional metabolic pathway involving oxidation of glucose and formation of three-, four-, five-, six-, and seven-carbon sugars.
In the pentose phosphate pathway glucose 6-phosphate is first oxidized and decarboxylated to a five-carbon sugar with the concomitant formation of NADPH. The five-carbon sugar then undergoes various combinations and transformations, similar to those of the Calvin cycle, leading eventually to the reformation of glucose 6-phosphate. Although the pathway can be used for the oxidation of glucose, it is more important as a source of five-carbon sugars, as a pathway for the oxidation of five-carbon sugars, and as a source of NADPH for such purposes as fatty acid synthesis.