In terms of photorespiration explain the following
I. How CAM and C4 plants differ from C4 pants
CAM and C4 plants are both types of plants that have adapted to minimize photorespiration, a process that occurs when the enzyme Rubisco binds with oxygen instead of carbon dioxide during photosynthesis. However, CAM and C4 plants differ from C3 plants in their mechanisms to reduce photorespiration.
1. CAM Plants:
CAM stands for Crassulacean Acid Metabolism and is a strategy employed by certain plants that live in arid conditions. These plants, such as cacti and succulents, have adapted to take in carbon dioxide at night and store it in the form of organic acids, primarily malic acid.
During the day, CAM plants close their stomata, tiny openings on the surface of leaves, to minimize water loss. The stored organic acids are then broken down to release carbon dioxide, which is then used for photosynthesis. This separation of carbon dioxide fixation at different times helps to reduce the potential for photorespiration.
2. C4 Plants:
C4 plants, such as maize and sugarcane, have developed special anatomical and biochemical adaptations to reduce photorespiration. These plants compartmentalize their photosynthetic processes in different cells.
In C4 plants, carbon dioxide is first fixed into a four-carbon compound called oxaloacetate in the mesophyll cells, separate from the site of Rubisco activity. This compound is then transported to bundle sheath cells, where it is decarboxylated to release carbon dioxide for the Calvin cycle.
This spatial separation allows C4 plants to maintain high carbon dioxide concentration around Rubisco, reducing the likelihood of oxygen binding and minimizing photorespiration. C4 plants are often found in hot and dry environments and show higher rates of photosynthesis compared to C3 plants.
Overall, both CAM and C4 plants have evolved unique mechanisms to minimize photorespiration, enhancing their efficiency in utilizing carbon dioxide and adapting to specific environmental conditions.