STRUCTURE of leaves allows GASES TO DIFFUSE in and out of cells
CO2 diffuses into air spaces within leaf, then it difuses into the cells where PHOTOSYNTHESIS occurs
Leaf structure adapted so this can happen easily.
Underneath leaf is EXCHANGE SURFACE - covered in small holes - STOMATA - which CO2 diffuses in through.
WATER VAPOUR and OXYGEN diffuse OUT through stomata (although some water vapour is also lost from all over leaf surface)
SIZE of the stomata controlled by GUARD…