CARBONDIOXIDE it is released by respiration as a by product. It then diffuses out of the cells and dissolves in the water layer around the spongy mesophyll . then it goes out of the life through the stomata by the process of diffusion along the concentration gradient. And it moves in the same way but this time is used up in the process of photosynthetical by type plant cell to produce glucose WATER water is absorbed by the root hair cells in the roots to make food in the process of photosynthesis The concentration of water out in the soil will be greater than in there root hair cells. So the water moves in through the partially permeable membrane of the root hair cell by the process of osmosis Water moves out of the leaf due to translation at day time through the leaf as water vapor by the process of diffusion ;-)