and has three reaction steps: fixation, reduction and regeneration.
The first step utilizes inorganic carbon dioxide and involves the carboxylation of ribulose-1,5-bisphosphate to produce 3-phosphoglyceric acid. This reaction is catalyzed by the enzyme,
Select OptionGTP and ATPcarbon dioxide and oxygenATP and NADPH
, the energy carriers produced during light-dependent photosynthesis, are used to reduce 3-phosphoglyceric acid to glyceraldehyde 3-phosphate.
This step involves two reactions: Firstly, 3-phosphoglyceric acid is
by the enzyme phosphoglycerate kinase and ATP, producing ADP and 1,3-bisphosphoglycerate.
Secondly, 1,3-bisphosphoglycerate is reduced by the enzyme glyceraldehyde 3-phosphate dehydrogenase and NADPH yielding NADP+ and glyceraldehyde 3-phosphate. Some of these glyceraldehyde 3-phosphates are utilized to produce
The third step involves a series of reactions to regenerate