Osmosis

• Osmosis


  Net movement of water molecules from a region of higher water potential to lower water potential through a permeable membrane

  
• The role of water as a solvent in organisms to aid with digestion, excretion and transport
• In Animals:


  If the concentration of the solute increases inside a animal cell this will cause the cell to burst because it has too much water and no cell wall
• Plant cells have a rigid cell wall which prevents them from bursting when there is an increase in solute concentration.
• Turgor pressure - The force that pushes against the cell walls of plant cells when they are full of water.
• When plants lose water by transpiration or evaporation, turgor pressure decreases causing the plant to wilt.
• Partially Permeable Membrane:


  Allows the passage of water molecules but no solute molecules
• Water potential:


  The potential energy of water molecules. Water moves from areas of high water potential to low water potential
• Solute Concentration:


  Higher solute concentration means lower water potential and vice versa