Question

Primary acceptor of $C{O}_2$ in photosynthesis is:

• A. phosphoric acid
• B. ribulose phosphate
• C. glucose
• D. ribulose 1, 5 biphosphate

Answer 1

Answer: (D)

The primary carbon dioxide acceptor in the dark reaction is Ribulose $1,5$ bisphosphate or RUBP, which is carboxylated by the enzyme Ribulose $1,5$ bisphosphate carboxylase oxygenase or RuBisCo. As a result of this carboxylation, two molecules of three carbon atom compound phosphoglyceric acid are produced as the first stable product of $C_3$ cycle.