Osmosis and Diffusion

Osmosis

Osmosis = movement of water molecules, across a partially permeable membrane, from a region of high concentration of water to a low concentration of water molecules.

It allows plants to take in water through their roots.

It is used in kidney dialysis machines to filter the blood.

Partially Permeable Membrane

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Small molecules, such as water can pass through the small holes in the membrane. But larger molecules like sugar cannot pass through the membrane.

Diffusion

Diffusion = movement of molecules, from a region of high concentration to a region of low concentration.

Oxygen diffuses into cells, and the waste carbon dioxide diffuses out.

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This video looks at diffusion in living cells