Hypotonic, Hypertonic And Isotonic Solutions

There are 3 types of solutions in accordance with their solute dissolved in water:

   a) Hypotonic solution contains a lower concentration of solute relative to
      another solution.
   b) Hypertonic solution contains a higher concentration of solute relative to
      another solution.
   c) Isotonic solution contains the same concentration of solute as another
      solution.

Effect of hypotonic,hypertonic and isotonic solutions in plant cells

 

Hypotonic solution

• Water diffuses into the large central vacuole by osmosis.
• This causes the vacuole to expand and push against the cell membrane.
• The cell membrane pushes against the cell wall.
• The cell is turgid.
• The turgidity within the plant cell is important to support and maintain the shape of the cell.
• The plant cell does not burst because the cell wall is rigid and strong enough to resist the turgor pressure.

              

 

Hypertonic solution 

• Water diffuses out of the large central vacuole by osmosis.
• The vacuole and the cytoplasm shrink.
• The plasma membrane pulls away from the cell wall.
• The cell becomes flaccid.
• This process is called plasmolysis.
• The flaccidity of plant cells causes wilting of the plant.
• If the plasmolysed cell placed in a hypotonic solution, water moves in by osmosis and the cell becomes turgid again. This process is called deplasmolysis.

          

 

Isotonic solution

• Water diffuses into and out of the cell at equal rates.
• There is no net movement of water across the plasma membrane.
• The cell retains its normal shape.

                

Effect of hypotonic,hypertonic and isotonic solutions in animal cells

Hypotonic solution

• Water enters the cell by osmosis.
• The red blood cells swells up and eventually burst because the plasma membrane is too thin to contain the water.
• The bursting of red blood cells is known as haemolysis.

        

Hypertonic solution

• Water moves out of the red blood cells by osmosis.
• This causes the red blood cell to shrink or shrivel.
• The red blood cells have undergone crenation.

          

Isotonic solution

• Water diffuses into and out of the cell at equal rates.
• The red blood cells maintained their shape.
• The concentration of a red blood cell is the same as the concentration as 0.85% sodium chloride solution.

       






      

Video below shows the experiment carry out to determine the effects of the egg membrane in the hypotonic and hypertonic solutions.