Osmosis

• Osmosis


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


  • Allows small molecules such as water to pass through it
  • Does not allow ions or larger molecules such as sucrose to pass through it
• Cell membranes are partially permeable
• Water can diffuse across cell membranes but sugars cannot
• Cells increase in size, and may even burst, if placed in water or very dilute solutions
• This is an example of osmosis, with the cell membrane acting as a partially permeable membrane