In leaves of C₄ plants malic acid synthesis during CO₂ fixation occurs in

Options

(a) epidermal cells
(b) mesophyll cells
(c) bundle sheath
(d) Guard cells

Correct Answer:

mesophyll cells

Explanation:

In leaves of C₄ plants, malic acid synthesis during CO₂ fixation occurs in mesophyll cells. The mesophyll cells perform C₄ cycle and the cells of bundle sheath perform C₃ cycle. CO₂ taken from the atmosphere is accepted by phosphoenol pyruvic acid (PEP)present in the chloroplasts of mesophyll cell of these leaves, leading to the formation of a 4-C compound, oxaloacetic acid (OAA). This acid is converted to another 4-C acid, the malic acid which enters into the chloroplast of bundle sheath cells and these undergoes oxidative decarboxylation yielding pyruvic acid (3C- compound ) and CO₂.