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Demonstration of Osmosis:
Aim:
To demonstrate the process of osmosis.
Materials required:
- Thistle funnel
- Beaker
- Semi-permeable membrane
- Sucrose solution
- Water
Procedure:
- Take a thistle funnel and cover its mouth with a semi-permeable membrane.
- Fill the funnel with sucrose solution.
- Now take a beaker with water and place the funnel in an inverted position inside the beaker.
Experimental setup
Observation:
We can observe that the water inside the beaker will diffuse across the semi-permeable membrane due to osmosis and will lead to the increase in the level of the solution in the funnel.
Inference:
From this, we can conclude that osmosis is a process in which solvent molecules move from a region of higher concentration to lower concentration across a semi-permeable membrane.
Imbibition:
A type of diffusion in which a solid plant material absorbs water and becomes swollen is known as imbibition.
Example:
Absorption of water by dry seeds and grapes.
The process of imbibition
Differences between osmosis and diffusion:
| S.No | Osmosis | Diffusion |
1. | This process can be observed only in a liquid medium. | It occurs in liquid, gas and solid mediums. |
2. | It requires a semi-permeable membrane. | It does not require a semi-permeable membrane. |
3. | Only solvent molecules diffuse in this process. | Molecules of both solute and solvent can diffuse. |
4. | During this process, the flow of particles occurs only in one direction. | During this, the flow of particles can be observed in all directions. |
5. | The movement in diffusion equalises concentration throughout the entire system. | Osmosis moves in such a way that it tries to equalise solvent concentration, but this does not happen. |
6. | It is not associated with the uptake of minerals and nutrients. | It helps in the uptake of minerals and nutrients. |
7. | It occurs only between similar types of solutions. | It occurs between similar and dissimilar types of solutions. |
Differences between active transport and passive transport:
S.No | Active transport | Passive transport |
1. | In this type of transport, molecules are moved across the cell membrane against the concentration gradient with the usage of ATP. | In this type of transport the molecules are moved within and across the cell membrane and thus transporting it through the concentration gradient, without using ATP (energy). |
2. | It is a process, that requires cellular energy. | It is a process, that does not require cellular energy. |
3. | In this process particles are moved from a region of lower concentration to a region of higher concentration. | In this process particles are moved from a region of higher concentration to a region of lower concentration. |
4. | It is a quick process. | It is a slow process. |
5. | It involves the usage of proteins known as carrier proteins. | Carrier proteins are not involved. |
6. | It is a unidirectional process. | It is a bidirectional process. |
7. | It transports various molecules in the cell. | It is involved in the maintenance of the equilibrium level inside the cell. |
8. | Exocytosis, Endocytosis, sodium-potassium pump are some of its types. | Osmosis, diffusion, and facilitated diffusion are some of its types. |
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