osmosis

• what is osmosis?

  the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
• dilute solutions contain a high concentration of water
• concentrated solutions contain a low concentration of water
• what is meant by partially permeable membrane?

  partially permeable membranes allow some molecules to pass through but not all molecules
• what does the cytoplasm contain?

  a relatively low concentration of water
• what happens to an animal cell if we place it a very concentrated solution?

  water will move out of the cell by osmosis and the cell will shrink
• what happens to a plant cell if we place it in water?

  water will move into the cell by osmosis and the cell will expand
• what prevents the plant cell from bursting?

  the cell wall, instead the cell becomes swollen (this is called turgid)
• if we place the plant cell into a concentrated solution, then water moves out of the plant cell by osmosis this causes the cell to shrink (this means the cell has become flaccid)