Diffusion is the process by which substance of the same temperature and atmospheric pressure spread towards regions of lower concentration from a higher concentration region.
Importance of diffusion:
1. Many physiological processes of living body is caused by diffusion.
2. During photosynthesis, plants intake carbon dioxide and expel oxygen by this process.
3. During respiration in animal, oxidation occurs due to this process.
4. Excess water is expelled out from plant by this process.
5. Nutrition element from blood is carried to the cell by this process.
Factors of Diffusion
1. Distance: shorter distance increases the rate of diffusion.
2. Concentration gradient: steeper concentration gradient means faster diffusion rate.
3. Surface area: A larger surface area increases the rate of diffusion.
Diffusion in Living Systems
When diffusion happens in living cells , the cells themselves do not have to expend any energy for it to take place. Rather the random movement of the particles is due to their own kinetic energy.
Many key processes in living organisms are dependent on diffusion. For example: respiration, photosynthesis, transpiration.
Osmosis is the spontaneous movement of solvent molecules through a semi-permeable membrane into a region of higher solute concentration from lower solute concentration.
Importance of Osmosis:
1. It helps the cell to do many biochemical reactions.
2. Plants absorb water and mineral salt by this process.
3. Stem and leaves become fresh due to this process.
4. Stomata of leaves opens and closes due to this process.