Osmosis is the movement of water molecules across a semi-permeable membrane from an area of higher water concentration to lower concentration until equilibrium is reached. Water molecules move randomly based on their kinetic energy. For osmosis, the potential of water to move is measured by osmotic potential, which is negative when other substances are dissolved in water. Water always moves from areas of lower to higher water potential. Osmosis plays a key role in transporting water and nutrients in the body and growth in plants. It can also be used to purify water in reverse osmosis desalination processes.

1. By : AMEER AZEEZBy : AMEER AZEEZ
BREESAM
Kutaisi, 2014

2. Osmosis is the net movement of water molecules
across a Partially-permeable membrane.
Water molecules move randomly with a certain
amount of kinetic energy…

3. and we can say it the phenomenon in
which the two solutions of two
different concentrations are separated
by the semi permeable membrane .
the molecules of the water move from
their higher concentration to their
lower concentration till the
concentration of both the solutions
becomes equal
.

5. Osmosis caused by a
concentration difference
of H2O

6. If a substance is dissolved in water, the
kinetic energy of the water molecules is
lowered.
This is because some water molecules
aggregate on the surfaces of the other
molecules…

7. For osmosis we talk about the potential
water molecules have to move – the OSMOTIC
POTENTIAL. Distilled water has the highest
potential (zero).
When water has another substance
dissolved in it, the water molecules
have less potential to move. The
osmotic potential is NEGATIVE.

8. Water molecules always move from less
negative to more negative water potential.
Net osmosis
= LN MN

9. The osmotic potential of a cell is
known as its WATER POTENTIAL.
For animal cells, the water
potential is the osmotic potential
of the cytoplasm.

10. Enough water ordinarily diffuses
in each direction through the red
cell membrane per second to
equal about 100 times the
volume of the cell itself

11. Yet normally the amount that diffuses
in the two directions is balanced so
precisely that (zero) net movement of
water occurs . Therefore, the volume
of the cell remains constant .
However, under certain conditions ,
a concentration difference for water ,
can develop across a membrane ,

12. When this happens, net movement
of water does occur across the cell
membrane, causing the cell either
to swell or shrink depending on the
direction of the water movement

13. 
When your hands are immersed in dishwater
for a long time, your skin looks bloated. This is
an effect of osmosis.
When you pour salt onto a slug, water diffuses
and slug shrinks as a result of osmosis.
When you cook food and put sauce in the liquid
part of your dish, some part of the solute
moves inside the solid part of the food you are
cooking. The solid part could be an egg, piece
of meat but the sauce is made of solute and
not water, so it will move into the food.
…

14. Osmosis also plays an important part in the
body .
“It helps in the transfer of water and various
nutrients between blood and fluid of cells”.
“Plants also use osmosis to take in water and
minerals essential for its growth “ .
“Reverse osmosis is a type of osmosis which is
used to convert sewage water into clean
drinking water”

15. In example on osmosis
take a thistle funnel and cover its mouth with a
parchment paper. and fill it with concentrated
sugar solution
place thistle funnel in a beaker containing water
and mark the level of sugar solution in the stem.
leave the apparatus undisturbed for 4-5 hours
you will observe that the level of sugar solution
in the stem rises and the level of water decreases
as water passes through the parchment paper
into the sugarsolution. it because of osmosis

16. Thank you for your
attention