Osmosis

• Osmosis is the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.
• In a dilute solution, scientists say that dilute solutions contain a high concentration of water.
• In a concentrated solution, scientists say that concentrated solutions contain a low concentration of water.
• A partially permeable membrane allows some molecules to pass through but not all molecules.
• The cytoplasm of cells is a relatively concentrated solution, containing a relatively low concentration of water.
• If a cell is placed in water, osmosis will take place, with water moving by osmosis from outside the cell to inside the cell.
• In the case of an animal cell, the water moving in will cause the cell to expand and it could even burst.
• If a plant cell is placed in water, water will move into the cell by osmosis and the cell will expand.
• The cell wall prevents the plant cell from bursting, instead the cell becomes swollen and scientists call this turgid.
• If a plant cell is placed in a concentrated solution, water moves out of the plant cell by osmosis, causing the cell to shrink.
• Scientists say that the cell has become flaccid.