Osmosis

• Osmosis is a passive process.
• Movement of water molecules from and area of high water potential to low water potential across a partially permeable membrane.
• Osmotic concentration 


  Amount of dissoved solutes in a solution(concentrated/dilute).
• Partially permeable membrane only allows water and small molecules through.
• Dilute solution: high water potential
• Concentrated solution: low water potential.
• Water potential: this is pressure formed by water molecules colliding.
• Pure water has a water potential of 0kPa, this is the highest it can be.
• Isotonic


  Same concentration of solutes and solvent.
• Hypertonic


  More solutes than solvents.
• Hypotonic


  More solvents than solutes.
• Crenation 


  Animal cells, shrivel up as water moves out of the cell.
• Lysis


  Disintegration of a cell by ruptured membrane, too much water moves in.
• Turgid


  Cell is swollen.