Osmosis

• Osmosis


  Movement of water from an area of a higher water potential to an area of lower water potential across a partially permeable membrane
• Water potential

  Pressure created by water molecules measured in kPa, pure water is 0 ans when solutes dissolve in water the water potential becomes negative, The more solutes dissolved the more negative water potential
• Isotonic


  Water potential the same in solution and in the cell within the solution
• Hypotonic

  Water potential more positive (higher) in solution than cell
• Hypertonic

  Water potential is more negative (lower) in solution than cell
• Animal cells in hypotonic solution (eg pure water)

  A lot of water will move into cell from solution via osmosis, due to a lack of cell wall, cell will burst
• Animal and plant cells in hypertonic solution

  Cell will shrink and shrivel due to large volume of water leaving cell via osmosis
• Plant cells in hypotonic solution

  Cell will turn turgid as they have a cell wall