pentosephosphate cycle
A biochemical pathway which provides an alternative system to glycolysis and the Krebs cycle for the metabolism of glucose. The hexose monophosphate shunt involves an intricate series of reactions in which glucose-6-phosphate is initially dehydrogenated and decarboxylated, and then resynthesized in smaller amounts. The reactions generate reducing power in the form of NADPH (reduced nicotinamide adenine dinucleotide phosphate) for fatty acid and steroid synthesis, and ATP. The hexose monophosphate shunt can contribute between 10 to 90% of energy supplied by carbohydrate metabolism; it is sometimes known as the direct oxidative pathway.
