Size of the particles that are diffusing is the factors that greatly affect the rate of diffusion. The rate of diffusion decreases if the thickness of the membrane becomes doubled while on the other hand, if the surface area of the membrane increases it doubled the rate of diffusion of the cell. If the size of particles is very small so it will diffuse if the membrane has double thickness.
That scrape on our knee will never heal and the blood loss due to bleeding will never be replaced. This is because RNA is inside of cells and without the ability to create new RNA you cannot replace missing cells. So the scrape will never heal if your cells cannot create new RNA.
