Question

Assertion:The primary $CO_{2}$ acceptor in $C_{4}$ pathway is $3$-carbon molecule phosphoenol pyruvate $(PEP)$.
Reason : The enzyme responsible for this fixation is $PEP$ carboxylase or $PEP$case.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (B)

Primary acceptor of $CO_{2}$ in $C_{4}$ plants is phosphoenol pyruvic acid $(PEP)$. Carboxylation is catalysed by enzyme $PEP$ carboxylase ($PEP$Case). First stable product in $C_{4}$ plant is $OAA$ (oxaloacetic acid), a $4C$ compound.