osmosis

• osmosis is the diffusion of water from a dilute concentration to a concentrated solution through a partially permeable membrane
• a partially permeable membrane allows some molecules to pass through but not all molecules
• the cytoplasm of cells is a relatively concentrated solution - has a low concentration of water

  of we place this cell in water then water will move inside the cell from outside
• in an animal cell water moving inside the cell will cause the cell to expand and could even burst
• if we place an animal cell in very concentration solution - water will move out of the cell and the cell will shrink
• in a plant cell if the cell expands the cell wall prevents it from bursting and instead the cell becomes swollen - scientists call this turgid

  when the cell shrinks - scientists call this flaccid
• plants use osmosis to absorb water