Ribulose 5-phosphate is one of the end-products of the

pentose phosphate pathway The pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt and the HMP Shunt) is a metabolic pathway parallel to glycolysis. It generates NADPH and pentoses (5-carbon sugars) as well as ribose 5-pho ...

. It is also an intermediate in the

Calvin cycle The Calvin cycle, light-independent reactions, bio synthetic phase, dark reactions, or photosynthetic carbon reduction (PCR) cycle of photosynthesis is a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into ...

. It is formed by

phosphogluconate dehydrogenase 6-Phosphogluconate dehydrogenase (6PGD) is an enzyme in the pentose phosphate pathway. It forms ribulose 5-phosphate from 6-phosphogluconate: :6-phospho-D-gluconate + NAD(P)+ \rightleftharpoons D-Ribulose 5-phosphate + CO2 + NAD(P)H + H+ It i ...

, and it can be acted upon by phosphopentose isomerase and phosphopentose epimerase. In plants, Ribulose 5-phosphate produced from the pentose-phosphate pathway is converted into Ribulose-1-5-bisphosphate by the enzyme

phosphoribokinase In enzymology, a phosphoribokinase () is an enzyme that catalyzes the chemical reaction :ATP + D-ribose 5-phosphate \rightleftharpoons ADP + D-ribose 1,5-bisphosphate Thus, the two substrates of this enzyme are ATP and D-ribose 5-phosphate, wh ...

See also