Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration.
Diffusion takes place in gases and liquids. Diffusion can also happen through some materials like cell membranes
Cells can use diffusion as a way of getting important particles in and out of them
Diffusion is particularly useful as it does not use any energy. It is a passive process.
Cell membranes are partially permeable -meaning that only some molecules can diffuse through, such as water, glucose and amino acids. However, proteins and starch cannot diffuse through
The 3 factors that affect the rate of diffusion are the concentration gradient, temperature and surface area
Factors affecting the rate of diffusion
Concentration gradient - the difference in concentration between two places
the steeper (bigger difference between) the concentration gradient, the quicker the rate of diffusion
Factors affecting the rate of diffusion
Temperature -higher temperatures give the particles more energy, making them move around faster
higher temperature= higher rate of diffusion
Factors affecting the rate of diffusion
Surface area
larger surface area= higher rate of diffusion
The larger the surface area to volume ratio, the quicker diffusion takes
place
The smaller an object is, the larger the surface area to volume ratio is
The larger an object is, the smaller the surface area to volume ratio is
