CRASSULACEAN ACID METABOLISM Meaning and
Definition
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Crassulacean acid metabolism (CAM) is a specialized metabolic pathway found in certain plants that allows them to adapt to arid or semi-arid conditions. CAM plants have evolved this mechanism to maximize water conservation while still allowing them to carry out photosynthesis.
In plants with CAM, the stomata, which are small openings on the plant's leaves, remain closed during the day to minimize water loss through transpiration. Instead, they open their stomata at night to uptake carbon dioxide (CO2) for photosynthesis. This CO2 is then stored as an organic acid, usually malate, in the plant's vacuoles.
During the daytime, when sunlight is available, the stored malate is released from the vacuoles and decarboxylated, meaning the CO2 is released. This CO2 is then fixed by the plant's chloroplasts in a process known as photosynthesis.
By separating the processes of CO2 uptake and fixation, CAM plants can conserve water since they can perform photosynthesis without having their stomata open during the hottest and driest parts of the day. This adaptation allows CAM plants to thrive in environments with limited water availability, such as deserts or rocky areas.
Overall, crassulacean acid metabolism is a unique and complex metabolic pathway in certain plants that enables them to optimize water usage while still conducting photosynthesis in challenging environmental conditions.
