Photosynthesis Question 88
88. The first carbon dioxide acceptor in $C_4$-plants is
[1990, 92]
(a) Phosphoenol-pyruvate
(b) Ribulose 1, 5-diphosphate
(c) Oxalo-acetic acid
(d) Phosphoglyceric acid
Show Answer
Answer : a
Hints & Solution
(a) The primary acceptor of $CO_2$ in $C_4$ plants is phosphoenol pyruvate or PEP. In mesophyll cells PEP combines with $CO_2$ and converted into a 4 carbon compound oxaloacetic acid by PEP carboxylase. In $C_3$ plants, ribulose 1, 5diphosphate is the primary acceptor of $CO_2$.
