Ribulose
Ribulose
A pentose sugar, also known as d -riboketose and d -erythropetulose; it has never been prepared in crystalline form, and exists only as a syrup. The structural formula of ribulose is shown below. 
Ribulose-5-phosphate occurs in animal and plant tissues. It can be converted to ribulose-l, 5-diphosphate by a phosphokinase enzyme acting in the presence of adenosine triphosphate (ATP). The ribulose-5-phosphate is also a significant intermediate in the carbohydrate metabolism through the pentose phosphate pathway. See Carbohydrate metabolism, Monosaccharide
Ribulose
(also D-erythropetulose), a monosaccharide belonging to the pentose (ketopentose) group. The esters of ribulose and phosphoric acid, namely, ribulose-5-phosphate and ribulose-1, 5-diphosphate, participate in important metabolic processes involving the breakdown of carbohydrates (pentose phosphate cycle), as well as in the production of carbohydrates in green plants during photosynthesis. Ribulose can be obtained either by the action of alkalis on arabinose or from formaldehyde in the presence of CaCO3.