Question

First product formed from Ribulose – 1, 5 – biphosphate in C3 cycle is

• A. 3 – Phosphoglycerate
• B. 1, 3 – biphosphoglyceric acid
• C. 4 – Phosphoglycerate
• D. dihydroxyacetone – 3 – phosphate

Answer 1

The correct option is A 3 – Phosphoglycerate

The calvin cycle or C3 cycle is a series of biochemical redox reaction that takes place in the stroma of chloroplast in photosynthetic organisms. Calvin cycle occurs in three stages : carboxylation, reduction and regenation.
Carboxylation is the first step in which carbon dioxide is fixed into a stable organic compound. In this step, carbon dioxide is utilised for the carboxylation of RuBP. This reaction is catalysed by the enzyme RuBP carboxylase which results in the formation of two molecule of 3- phosphoglyceric acid.