Diffusion and osmosis in Details

Diffusion and osmosis

Diffusion and Osmosis :

Diffusion -the process by which molecules move from densely populated locations to sparsely populated ones. When molecules or particles migrate spontaneously from one region of high concentration to another region of low concentration across a membrane, this is known as diffusion. It is merely the statistical result of motion at random.

The gradient of concentration differences between high and low will gradually diminish (become increasingly shallow) until the concentrations are equal. The movement of molecules toward lower-concentration regions along a concentration gradient is constant. Consider how food colouring would disperse in a glass of water or how air freshener might be sprayed over a space.

Diffusion is a classic illustration of thermodynamics since it lowers Gibbs free energy while increasing entropy (randomness).

Equilibrium – when the molecules are uniformly distributed.

Concentration gradient – a variation in concentrations in a given area

Osmosis – The process of water diffusion through a semipermeable membrane is called osmosis.
Where there is a high concentration of solute and a low concentration of water, water will flow in that direction. Osmosis controls hydration, the inflow of nutrients, and the outflow of wastes, among other functions. Water molecules are free to travel through the cell membrane in both ways, either in or out.

*A simple rule to remember is: salt sucks.

Since salt is a solute, it will attract water in its direction whether it is concentrated within or outside the cell. We become thirsty after eating anything salty for the same reason.

Type of Solutions :

1. Isotonic Solutions

Water will travel back and forth across a membrane if the solute concentration (salt) is the same on both sides, but it will have no impact on the overall amount of water present on either side. Same meaning as “ISO.”

2. Hypotonic Solutions

Since there are less solute (salt) molecules outside the cell due to the term “HYPO,” which means “less,” water will enter the cell as a result. The cell will expand and take up more water. The core vacuoles will fill in plant cells, making the plant stiff and unyielding. The cell wall prevents the plant from exploding. Animal cells may be in risk of bursting, but contractile vacuoles will push water out of the cell to stop this from happening.

3. Hypertonic Solutions

Because there are more solute (salt) molecules outside the cell than within, which is what the name “HYPER” denotes, water is drawn in that direction. In plant cells, water is lost from the central vacuole, which causes the cells to contract and wilt. Animal cells also experience cell shrinkage. The cell may perish in any scenario.

Therefore, it is risky to drink sea water. Although it is a misconception that drinking sea water can make you go mad, drinking sea water will hasten the process of dehydration (and eventual death) for persons who are marooned at sea. Due to the fact that “salting fields” would damage the crops in the field and result in food shortages, it was also a typical strategy used during wartime.

Osmosis and Diffusion are both examples of passive transport, meaning that no energy is needed for the molecules to enter or exit the cell. Facilitated diffusion is the process whereby big molecules that are unable to traverse the plasma membrane are “helped” across by carrier proteins.


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