Ribulose is a five-carbon monosaccharide. It is a reducing sugar. Its molecular symbol is C5H10O5. Since it contains a keto group, it is called a ketopentose sugar. Ribulose acts as a CO2 consumer in photosynthesis and produces ribulose 1, 5 bisphosphate. Ribulose 1, 5 bisphosphate is oxidized to form carboxyl compounds. Dr. Siddiq Publications