This document discusses osmosis and transport across membranes. It defines osmosis as the process by which water molecules pass through a semi-permeable membrane from an area of higher water concentration to lower concentration. There are different types of osmosis including endosmosis, exosmosis, and reverse osmosis. Transport across membranes can occur through passive transport mechanisms like diffusion and facilitated diffusion, or active transport which requires energy. Osmosis and transport are important biological processes that allow for nutrient intake, waste removal, and homeostasis in living cells and organisms.

3. OSMOSIS AND TRANSPORT ACROSS MEMBRANE
Assignment Number: 01
SUBMITTED TO:
DR. MUBIN MUSTAFA KIYANI
SUBMITTED BY:
MUHAMMAD AKRAM

4. OSMOSIS AND TRANSPORT ACROSS
MEMBRANE
SUBTITILES
 DEFINITIONS
 PROCEDURES
 IMPORTANCE
 EXAMPLES
 TYPES OF OSMOSIS
 TYPES OF TRANSPORT
 ACTIVE AND PASSIVE

5. OSMOSIS
Osmosis is the process by which water molecules pass through a
membrane from a region of higher water concentration to a region of lower
water concentration.

6. OSMOSIS IN BIOCHEMISTRY
• Osmosis is a process by which the molecules of a solvent pass from a solution of
low concentration to a solution of high concentration through a semi-permeable
membrane.

7. Procedure of Osmosis
In normal osmotic processes, solvent flows
across a semipermeable membrane
from a dilute solution to a more concentrated
solution until equilibrium is reached.
Applying high pressure to the concentrated
side causes the process to reverse.

8. TYPES OF SOLUTION
An ISOTONIC have same concentration of solutes both in and out of the cell
 An HYPOTONIC have higher concentration inside than out of the cell.
An HYPERTONIC have higher concentration outside than inside of the cell

9. TERMS USED IN OSMOSIS
OSMOTIC POTENTIAL:
The potential of water molecules to move from a hypotonic solution to a hypertonic
solution across a semi permeable membrane.
PRESSURE POTENTIAL:
 The minimum pressure that must be applied to a solution to stop the flow of solvent
molecules through a semipermeable membrane.

10. TYPES OF OSMOSIS
• ENDOSMOSIS
The process in which water
molecules enter into the cell.
• EXOSMOSIS
The process in which water
molecules moves out of the cell.

11. APPLICATION OF OSMOSIS
 It is used in kidneys dialysis.
Assist plants in receiving water.
Helps in in the preservation of fruit and milk.
It can be reversed to remove salt and other impurities from water.
Osmotic generation of power.

12. EXAMPLES OF OSMOSIS:
Feeling thirsty after having salty food.
Dialysis of kidney in the excretory system.
Swelling of resins and other seeds when they are soaked in
water.
Movement of salt-water in the animal cell across our cell
membrane.

13. IMPORTANCE OF OSMOSIS
Osmosis plays an important role in the transportation of nutrients
and the release of metabolic waste products within a living cell.
It stabilizes the internal movement of water and intracellular fluid
levels within a cell.
 Osmosis also controls cell-to-cell diffusion and maintains the
mechanical structure of a cell.

14. TRANSPORT ACROSS THE MEMBRANE
• Transport across the plasma membrane occurs unaided in simple
diffusion, i.e., molecules of gases such as carbon dioxide and oxygen,
as well as small molecules like ethanol, enter the cell by crossing the
cell membrane without any assistance
• There are two types of transport
• Active transport
• Passive transport

15. ACTIVE TRANSPORT
Active transport is the transport of molecules that require the use of
energy, in the form ATP to help them cross the cell membrane.

16. PASSIVE TRANSPORT
Passive transport is a type of cellular transport in which substances such as
ions and molecules move down their respective concentration gradients.

17. DIFFUSION
The movement of individual molecules of substance through a
semipermeable barrier from an area of higher on centration to an area of
lower concentration.

18. FACILITATED DIFFFUSION
It is a selective process.
the membrane allows only selective.
prevents other molecules
passing through the membrane.

19. TRANSPORT PROTEINS
Proteins that transport substances across biological membranes.
Transport proteins are found within the membrane .

20. IN PLANTS
Osmosis helps in retaining turgidity of cell.
Role in the movement of stomata during transpiration.
 The opening and closing of stomata maintained by osmosis.

21. IN ANIMALS
Plants and animals achieve homeostasis.
 Makes it possible for living things to survive.
 Osmosis plays an important role in the human body, in the gastro-intestinal system and the kidneys.

22. IMPORTANCE OF TRANSPORT ACROSS
MEMBRANE
Intake of nutrient.
Removal of wastes.
Communication with environment and other cells.
Blocking passage of harmful substances.

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