Osmosis

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Cells, 7/8 Y3

Osmosis

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• ​Osmosis is a special type of passive transport. It is the diffusion of water. Specifically, it is facilitated diffusion of water with a channel protein.

• Osmosis is the movement of water from a high concentration of water to a low concentration of water.

Cells, 7/8 Y3

Osmosis

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​​We don’t refer to the concentration of water in a solution. We refer to the concentration of the solute in a solution.

Cells, 7/8 Y3

Osmosis

• ​Osmosis occurs across cell membranes when the solute concentration is different inside and outside a cell.

Cells, 7/8 Y3

Osmosis

• When the concentration of solute is lower outside a cell, the concentration of water is higher. Therefore, water moves from outside the cell to inside the cell.

Cells, 7/8 Y3

Osmosis

• ​When the concentration of solute is higher outside a cell, the concentration of water is lower. Therefore, water moves from inside the cell to outside the cell.

Cells, 7/8 Y3

Osmosis

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• If the solute concentration is the same inside of the cell and outside of the cell, the water does not diffuse across the membrane.