Question
How does uptake of CO2 from the atmosphere into the leaf cells take place?
Solution
During photosynthesis in a leaf, the CO2 present in cells (cytoplasm) is being used up and fixed as carbohydrates. As a result, the concentration of CO2 in cell-cytoplasm falls. So CO2 present in intercellular spaces diffuses into cells. Consequently, a diffusion gradient between the air and the intercellular spaces set up and CO2 diffuses from the atmosphere into intercellular spaces and then into cells.
Movement of CO2 in green plant cells during day-light.
Cell → intercellular spaces → stomata → atmosphere.
