How does Carbon Dioxide enter the Leaf

1. In Daylight when photosynthesis occurs ⇒ Carbon dioxide in the leaf is rapidly used up
2. Carbon dioxide concentration in the leaf → becomes lower than the atmospheric air ⇒ diffusion gradient exists
3. Thus, $C{O}_2$ diffuses from the surrounding air through the stomata into the intercellular air spaces
4. Surfaces of mesophyll cells are always covered with a thin film of moisture. this is so that $C{O}_2$ can dissolve into it
5. $C{O}_2$ dissolves into thin film of moisture on the mesophyll cells
6. Dissolves $C{O}_2$ then diffuses from cell to cell until it reaches inner cells

---