In sugarcane plant 14CO2 is fixed to malic acid, in which the enzyme that fixes CO2 is
- ribulose bisphosphate carboxylase
- phosphoenolpyruvic acid carboxylase
- ribulose phosphate kinase
- fructose phosphate.
Answer
(2) phosphoenolpyruvic acid carboxylase
Solution
Sugarcane is a C4 plant.
As per NCERT, in mesophyll cells of C4 plants the primary CO2 acceptor is phosphoenolpyruvate (PEP), and the enzyme for this fixation is PEP carboxylase (PEPcase).
⇒ PEP + CO2 → oxaloacetic acid, which is then converted to malic acid.
∴ The enzyme is phosphoenolpyruvic acid carboxylase.
Answer: (2)