3.2.1 Types of Solution – Hypotonic


What is Hypotonic Solution?

Hypotonic solution is the solution that has higher water potential than the other solution.

Water Concentration and Solute Concentration of a Cell in a Hypotonic Solution


  1. Water concentration: Water concentration inside the cell is lower than outside the cell.
  2. Solute Concentration: Solute concentration inside the cell is higher than outside the cell.



Effect of Hypotonic Solution on Animal Cell




  1. If an animal cell such as red blood cell is placed into a hypotonic solution, water molecules is transported into the red blood cells by osmosis (as shown in the diagram above).
  2. The red blood cells will inflate and finally burst because the thin membrane cannot withstand the high pressure inside the cell.
  3. The red blood cells are said to undergo haemolysis.



The Youtube video above shows the effects of hypotonic solution on red blood cells. We can see that the cells finally burst and become "blur" under the microscope.



Effect of Hypotonic Solution on Plant Cell




  1. When a plant cell is placed in a hypotonic solution, water molecules is transported into the cell by osmosis.
  2. The water is then stored in vacuole causing it to expand and exerts pressure on the cell wall. This pressure is called turgor pressure.
  3. The turgor pressure caused the plant cell to become firm or turgid.
  4. The rigid cell wall prevents cell from bursting.