NEETBotanyPhotosynthesis in Higher Plants
Where does the Calvin pathway occur in C4 plants?
Options
- AMesophyll cells
- BStomata
- CGuard cells
- DBundle sheath cells
Correct answer
D. Bundle sheath cells
Step-by-step solution
The primary CO2 acceptor is a 3-carbon molecule phosphoenol pyruvate (PEP) and is present in the mesophyll cells. The enzyme responsible for this fixation is PEP carboxylase or PEPcase. It is important to register that the mesophyll cells lack RuBisCO enzyme. The C4 acid OAA is formed in the mesophyll cells. It then forms other 4-carbon compounds like malic acid or aspartic acid in the mesophyll cells itself, which are transported to the bundle sheath cells. In the bundle sheath cells these C4 acids are broken down