Question

3- PGA is first stable product in

• A. Carbon-reduction cycle
• B. C${}_4$ cycle
• C. HMP shunt
• D. CAM

Answer 1

The correct option is A Carbon-reduction cycle

The first step in the Calvin cycle is carboxylation of RuBP by atmospheric $C{O}_2$ in the presence of an enzyme, RuBP carboxylase/oxygensae (RuBisCo). This RuBP after combining with $C{O}_2$ results in the formation of an unstable-6-carbon compound. It splits into 2 molecules of a 3-carbon compound called as 3-phosphoglycerate (3-PGA).