CAM plants function using crassulacean acid metabolism.Like C₄ plants,CAM plants provide a preparatory step for the Calvin cycle.CAM plants are found in hot,dry environments;to prevent desiccation,they keep their stomata closed during the day.They take in carbon dioxide at night while stomata are open.To increase the concentration of carbon dioxide available to the enzyme rubisco and minimize the degree of photorespiration,the CAM plants carboxylate _____.
A)phosphoenolpyruvate
B)oxaloacetate
C)organic acids
D)ribose

Question

Quizplus · Accepted Answer

CAM plants carboxylate organic acids at night in order to increase the concentration of carbon dioxide available to the enzyme rubisco and minimize the degree of photorespiration. Option A, phosphoenolpyruvate (PEP), is the primary acceptor of carbon dioxide in C4 plants but not in CAM plants. Option B, oxaloacetate, is the first acceptor of carbon dioxide in C4 plants, but not in CAM plants. Option D, ribose, is a sugar molecule and not involved in carbon fixation in CAM plants.

CAM Plants Function Using Crassulacean Acid Metabolism