 Ribulose 5-phosphate can alternatively undergo a series of isomerizations as well as transaldolations and transketolations that result in the production of other pentose phosphates as well as fructose 6-phosphate and glyceraldehyde 3-phosphate (both intermediates in glycolysis).The enzyme ribose-phosphate diphosphokinase converts ribose-5-phosphate into phosphoribosyl pyrophosphate.R5P consists of a five-carbon sugar, ribose, and a phosphate group at the five-position carbon.