Animation - How Facilitated Diffusion Works

How can cells control diffusion?

One way in which cells can control diffusion is through the control of movement of particular types of molecules. Some molecules can pass freely through a cellular membrane. Large polar molecules and ions cannot diffuse through the lipid bilayer. Carrier proteins can move molecules across the membrane. Cells will have carrier proteins for specific molecules. These molecules will pass freely across the membrane while other molecules will not. The types of carrier proteins found on a cell are related to cell function.

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