The Calvin cycle is the primary carbon dioxide fixation pathway found in all green plants, including Solanum lycopersicum. This important cycle of chemical reactions can be divided into three stages: fixation, reduction, and regeneration. In the fixation stage, D-ribulose-1, 5-bisphosphate (RuBP) is reduced into two molecules of 3-phospho-D-glycerate by the enzyme RubisCO (ribulose biphosphate carboxylase). In the reduction stage the two molecules of 3-phospho-D-glycerate are phosphorylated and then reductively dephosphorylated to D-glyceraldehyde 3-phosphate. Three iterations of this cycle result in 3 molecules of carbon dioxide fixed, thus forming 6 molecules of D-glyceraldehyde 3-phosphate. The final stage (regeneration) is a highly complex series of rearrangement reactions that result in the regeneration of RuBP, the key carbon dioxide acceptor.

Calvin-Benson-Bassham cycle References