4.1 Diffusion

4.1 Diffusion

Core

• Define Diffusion

• Describe the importance of diffusion of gases 

and solutes and of water as a solvent

Diffusion can be defined as the net movement of particles from an area of high concentration to one of low concentration down a concentration gradient. An example could be the diffusion of gasses from the air into leaves through Stomata. In the air there is a higher amount of Carbon Dioxide than there is in leaves. Therefore the C02 moves down its concentration gradient (High-Low) from the air, through the stomata and into the leaf. We say that the C02 has diffused into the leaf.

Diffusion is incredibly important to life. When we respire we produce Carbon Dioxide and this must be excreted as it is bad for cells and would damage them, C02 rich blood is taken to the lungs and diffused out of the blood by alveoli, it is then excreted by the lungs. Without diffusion, manylife processes could not take place.