the net movement of anything from a region of higher concentration to a region of lower concentration.
if SA:V ratio is small,
movement of substances across the membrane is low & inefficient. (Diffusion)
if SA:V is large,
movement of substance is fast and efficient (Diffusion)
what is the affect of shape and size within a membrane?
Whether or not a substance moves across the membrane & how its transported. this is as specific requirements are needed in order to attain nutrients efficiently.
