Question

The acid which gets accumulated during night in CAM plants is ___________.

• A. PEPA
• B. Oxaloacetic
• C. Pyruvic
• D. Malic

Hint:

CAM plants store CO\textsubscript{2} at night in the form of malic acid to minimize water loss.

Answer 1

The Correct Option is D

Step 1: Understanding CAM plants.
CAM (Crassulacean Acid Metabolism) plants open their stomata at night to reduce water loss and fix carbon dioxide in the dark phase.
Step 2: Acid formation at night.
During night, CO\textsubscript{2} is fixed into oxaloacetic acid, which is then converted into malic acid and stored in the vacuoles of leaf cells.
Step 3: Analysis of options.
(A) PEPA: Incorrect — PEPA acts as a CO\textsubscript{2} acceptor, not the stored acid.
(B) Oxaloacetic: Incorrect — it is an intermediate, not accumulated.
(C) Pyruvic: Incorrect — not involved in CAM acid storage.
(D) Malic: Correct — malic acid accumulates during night in CAM plants.
Step 4: Conclusion.
The acid accumulated during night in CAM plants is malic acid.