ribulóz5foszfát

Ribulóz-5-foszfát, also known as ribulose-5-phosphate, is a carbohydrate molecule that plays a crucial role in biological pathways. It is a phosphorylated sugar that is an intermediate in both the Calvin cycle and the pentose phosphate pathway. In its most common form, it is a ketopentose, meaning it has five carbon atoms and a ketone functional group.

Within the Calvin cycle, the process of carbon fixation in photosynthesis, ribulóz-5-foszfát is a direct precursor to ribulose-1,5-bisphosphate. This conversion is catalyzed by the enzyme ribulose-5-phosphate kinase, which uses ATP to add a phosphate group. Ribulose-1,5-bisphosphate is the molecule that initially accepts carbon dioxide during photosynthesis.

In the pentose phosphate pathway, ribulóz-5-foszfát is generated from glucose-6-phosphate. This pathway is essential for producing NADPH, a reducing agent used in various biosynthetic reactions and for protecting cells against oxidative damage, and for generating precursors for nucleotide synthesis. Ribulóz-5-foszfát can then be isomerized to xylulose-5-phosphate or epimerized to ribose-5-phosphate, both of which are important for nucleotide biosynthesis.