The worksheet A8.1 (moving chemicals) should be completed by tomorrow. Diffusion is the movement of particles from high to low concentration. This is important in taking in oxygen, removing carbon dioxide and in absorbing digested food into the blood stream. The diffusion is quicker the bigger the difference in concentration there is and the greater the surface area is. The lungs have alveoli to increase surface area and the small intestine has thin folds called villi.

diffusion