Diffusion

• Diffusion is the net movement of molecules or ions from a region of high concentration to low concentration, until an equilibrium
• Diffusion allows nutrients and oxygen to enter the cell, and waste products and hormones to leave the cell
• Diffusion utilises the kinetic energy of the molecules, meaning it is a passive process
• Factors affecting rate of diffusion include Surface Area, Concentration Gradient, and Length of Diffusion Pathway
• Small, lipid-soluble, non-polar molecules can slip through gaps in the plasma membrane
• Whilest water is polar, it is small enough to move through the membrane by osmosis