Osmosis

• Osmosis


  The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
• Dilute solution

  • Contains a high concentration of water
  • Contains a low concentration of solute (e.g. sugar)
• Concentrated solution

  • Contains a low concentration of water
  • Contains a high concentration of solute (e.g. sugar)
• Osmosis

  Water diffuses from the dilute solution to the concentrated solution through a partially permeable membrane
• Cell placed in water

  Water moves into the cell by osmosis, causing the cell to expand
• Cell placed in concentrated solution

  Water moves out of the cell by osmosis, causing the cell to shrink
• Animal cell

  • Cytoplasm is a relatively concentrated solution
  • Cell can burst if too much water enters
• Plant cell


  • Cell wall prevents the cell from bursting when water enters
  • Cell becomes turgid (swollen) when water enters
  • Cell becomes flaccid (shrunken) when water leaves