- Dissolved substances can move into and out of cells by diffusion and osmosis.
- Diffusion is the spreading of particles of a gas or of any substance in solution. This results in a net movement from a region of high concentration to a region of low concentration. The greater the difference in concentration, the faster the rate of diffusion. Oxygen required for respiration passes through cell membranes by diffusion.
- Cell membranes let things pass in and out of the cell from where theres a high concentration to where there is a low concentration. They move about randomly so they move both ways but if there are a lot more particles on one side of the membrane…