How does surface area to volume ratio affect the rate of diffusion?
Surface area to volume ratio, in simple means the size of surface area to the volume of substance that can pass through it at a particular time.
Amoeba and some bacterias are flat and have large surface area to volume ratio. So the diffusion rate is very high due to large surface area.
Where as humans have small surface area: volume so diffusion is very slow or does not take place at all.
As the ratio gets smaller, it takes longer for items to diffuse.
When the cell increases in size, the volume increases faster than the surface area, because volume is cubed where surface area is squared.
When there is more volume and less surface area, diffusion takes longer and is less effective. This is because there is a greater area that needs to receive the substance being diffused, but less area for that substance to actually enter the cell.
this is actually why cells divide. When they become too large and it takes too long for them to transport materials across the cell, they lose efficiency and divide in half to raise the surface area to volume ratio.