Ribulose-1,5-bisphosphate

Structural formula
General
Surname	Ribulose-1,5-bisphosphate
other names	RubP 2
Molecular formula	C 5 H 12 O 11 P 2
External identifiers / databases
CAS number 2002-28-0 PubChem 123658 ChemSpider 110238 Wikidata Q418860
properties
Molar mass	310.09 g mol −1
Physical state	firmly
safety instructions
GHS labeling of hazardous substances Sodium salt hydrate danger H and P phrases H: 301-311-315-319-331-335 P: 261-280-301 + 310-305 + 351 + 338-311
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Ribulose-1,5-bisphosphate (abbreviated RubP ₂ ), formerly also called ribulose-1,5-diphosphate , is a sugar molecule ( monosaccharide ) with five carbon atoms to which two phosphate residues are attached. It plays as acceptor for carbon dioxide in the carbon dioxide assimilation in the Calvin cycle a large role in the dark reaction of photosynthesis .

The enzyme that binds CO ₂ to ribulose-1,5-bisphosphate is called ribulose-1,5-bisphosphate-carboxylase / oxygenase (RuBisCO) and plays an important role as the starting point for the Calvin cycle. After the CO ₂ fixation, the molecule that has become unstable due to the addition of water immediately breaks down into two 3-phosphoglycerate molecules, from which glucose can then be produced after further steps. Ribulose-1,5-bisphosphate is then regenerated from phosphoglycerate.

Fructose-6-phosphate + 2 glyceraldehyde-3-phosphate + dihydroxyacetone phosphate + 3 ATP 3 ribulose-1,5-bisphosphate + 3 ADP ${\displaystyle \mathrm {\longrightarrow } }$

In order to emphasize that the two phosphate residues are connected to the sugar molecule at different points, the term bisphosphate has become established internationally instead of the previously used diphosphate .

literature

• Jeremy M. Berg, John L. Tymoczko, Lubert Stryer (2007): Biochemistry. Spektrum Akademischer Verlag, 6th edition, ISBN 3-8274-1800-3 .

Individual evidence

1. ↑ ^{a b} Data sheet D-Ribulose 1,5-bisphosphate sodium salt hydrate from Sigma-Aldrich , accessed on April 22, 2011 ( PDF ).