Increasing the Rate of Movement across a Membrane

The rate of movement across a cell membrane by diffusion can be increased by increasing the surface area of the membrane, increasing the concentration gradient across the membrane and decreasing the diffusion distance.Microvilli are finger-like projections of the cell surface membrane about 0.6μm in length. Collectively, they make up the 'brush-border' of the cell. This increases the surface area for diffusion.For substances that require carrier proteins or channel proteins, increasing the number of channel or carrier proteins increases the rate of movement of these substances across the membrane.