Question

The enzyme that is not found in a C3 plant is

• A. PEP Carboxylase
• B. ATP synthase
• C. NADP reductase
• D. RuBP Carboxylase

Answer 1

The correct option is A PEP Carboxylase

RuBP Carboxylase:

RuBP carboxylase is the enzyme that is involved in the fixation of atmospheric carbon dioxide in the C3 cycle.

• It catalyzes the reaction between the primary acceptor of $C{O}_2$, RuBP, with $C{O}_2$
• However, it is found in both C3 and C4 plants.

PEP carboxylase:

• PEP carboxylase catalyzes the fixation of atmospheric carbon dioxide with phosphoenolpyruvate (PEP) in the C4 pathway.
• It is found only in C4 plants and not in C3 plants.

$NADP$ reductase:

• $NADP$ reductase catalyzes the reduction of $NADP$ to $NADPH$ during light reactions.
• It is also found both in C3 and C4 plants.

ATP synthase:

ATP synthase catalyzes the release of ATP synthesis when a photon passes through it.

• It is present within the thylakoid membrane.
• It is present both in C3 and C4 plants.

Final answer: PEP Carboxylase