HypotonicHypertonicAndIsotonic Sept 24

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The effects of hypotonic,
hypertonic and isotonic
solution on animal and plant
cells.
• Hypertonic
- Concentration with higher solute concentration
and less water concentration
• Hypotonic
- lower solute concentration and more water
concentration
• Isotonic
- Solution in which water molecule and solute
molecule are equal in concentration.
Animal and plant cell In an
isotonic solution
• Isotonic solution is a solution in which the
concentration of solutes is equal, so:
- Water diffuses into and out of the cell at
equal rates.
- There’s no net movement of water across
the plasma membrane
- The cells retain their normal shape
Animal and plant cells in a
hypotonic solution
• Solution which contain higher concentration of
water and lower concentration of solutes is
called as hypotonic solution.
• Since the concentration of water is higher
outside the cell, there is a net movement of
water from outside into the cell.
• Cell gains water, swells and the internal
pressure increases. Eventually burst
(haemolysis).
The effects of hypertonic solution
in animal and plant cell
• Contain higher concentration of solutes and less
of water than a cell.
• Since the concentration of water is higher
within the cell, there is a net movement of water
from inside to outside of the cell. (water leaves
the cell by osmosis)
• Causes the cell to shrink as its internal pressure
decreases.
Hypertonic solution on plant cell
• Water diffuses out of the large central vacuole
by osmosis. Water lose from both vacuole and
cytoplasm cause to shrink.
• Plasma membrane pulls away from the cell wall.
(plasmolysis).
• Become flaccid and less turgid.
• Cell wall doesn’t shrink because it is strong and
rigid.
• If plasmolysis continues, death may result.
• If we placed the plasmolysed plant cell in a
hypotonic solution (pure water), water
moves into the cell by osmosis and
become turgid again. (deplasmolysis)
Food preservation
• The concept of osmosis and diffusion are applied
in the preservation of food, such as fruits, fish
and vegetables by using preservatives (salt,
sugar/ vinegar)
• Salt solution of hypertonic to tissue of fish. So
water leaves the fish tissue and enter the salt
solution by osmosis.
• Fish become dehydrated and cell crenate.
Therefore, bacteria can’t grow in fish tissue and
bacteria cell will crenate.
• Preserved fish don’t decay so soon and last
longer.
• Preservation with vinegar
• Mangoes are soaked in vinegar which has low
pH, vinegar diffuses into the tissues of the
mangoes and become acidic.
• Low pH prevents the growth of microorganism
in mangoes and preserved mangoes can last
longer.
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