Diffusion and Osmosis are the two activities that preforms the role of transporting materials to or from the cell. Both are the passive transportation, that means such spontaneous process that does not needs any energy.
The first one (diffusion) is the movements of molecules from the region of higher concentration ot the lower concentration trough any medium ( solid, liquid or gas), while osmosis occurs usually in water as it is the process of movements of molecules from the diluted solution to the concentrated solution by the semi-permeable membrane.
This article is about the differences and similarities observed in both the processes, their applications and few examples are also highlighted.
What is Diffusion
When a drop of color is dropped in a glass of water, it quickly starts spreading to the entire region of the glass through the water as a medium. By this example, it can be understood that, the movements of molecules or particles took place from the region of higher concentration to the region of lower concentration and got diffused.
What is Osmosis
he absorption of water molecules from the soil to the roots of a plant is the simple example by which osmosis can be understood. The movement of solvent through a semi-permeable membrane, as osmosis occurs in liquid medium ( generally water) only so it is said that when the solvent pass from a solution of higher (dilute) concentration to the lower concentration, just to equalize the concentration level on both the sides of semi-permeable membrane is osmosis.
As the particles are incapable of passing the barrier of semi-permeable membrane, so only water (or other solvent) are only able to move. The more it attains the equilibrium, the more the stable and thermodynamically suitable the process becomes.
Difference Between Diffusion and Osmosis
Membrane
There is no membrane barrier in the diffusion process.
Osmosis occurs only by the semi-permeable membrane.
Medium
Diffusion can occur in all the medium whether it is solid to liquid, solid to gas, liquid to liquid, liquid to gas, or gas to gas.
Osmosis takes place only in liquid medium.
Types of molecules
In the diffusion process both solute and solvent are able to cross the membrane.
In the case of osmosis, only same type of solvents are allowed to pass through the medium.
Directions of flow of molecules
In the diffusion, the flow of molecules occurs in all the directions.
However, in osmosis the flow of molecules is specified to one direction only.
Region of movements
Diffusion takes place from the region of higher concentration to the lower concentration.
Osmosis occurs from the dilute solution to the higher concentrated solution.
Reversible/irreversible
Diffusion is a continuous process and irreversible too.
Osmosis is reversible and can be paused by forcing on the solution side.
Influencing factors
Diffusion activity does not gets affected by the solute potential.
Osmosis activity gets influenced by the solution potential.
Dependent factors
This process depends on free energy of various particles or molecules.
Osmosis depends on the free energy of rate of reduction of one solvent .
Molecules concentration at the end of the process
After the completion of the process, the concentration of diffusing molecules gets equalized.
After the completion of the process, the concentration of the solvent is not equalized.
Effect of Turgor pressure
Diffusion is not effected by the turgor pressure.
Osmosis, is effected by the turgor pressure as it created the hinderance of the solvents in the cell.
Example
Diffusion of any spray into the air will get spread easily into the near by environment.
Cellular waste being moved out of the cell by the water molecules is an example of osmosis.
One more example of osmosis is the death of plant due to the overwatering as the plants becomes too bloated and is unable to get back to the saturated soil.
Similarities Between Diffusion and Osmosis
- Diffusion and Osmosis are the passive transportation process, and therefore are spontaneous and does not requires energy to work.
- At the end of both the processes the concentration of the molecules or solution gets equalized.
- It is the common process for the living as well as non-living organisms.
Quick Comparison: Osmosis Vs Diffusion
| Diffusion does not any membrane to move to the region of higher concentration. | Osmosis occurs only by the semi-permeable membrane. |
| Diffusion can occur in all the medium whether it is solid to liquid, solid to gas, liquid to liquid, liquid to gas, or gas to gas. | Osmosis takes place only in liquid medium. |
| In the diffusion process both solute and solvent are able to cross the membrane. | The process of Osmosis, occurs only in same type of solvents that are allowed to pass through the medium. |
| In the diffusion, the flow of molecules occurs is in all the directions. | In osmosis the flow of molecules is specified to one direction only. |
| Diffusion takes place from the region of higher concentration to the lower concentration. | Osmosis occurs from the dilute solution to the higher concentrated solution. |
| Diffusion is a continuous process and irreversible too. | Osmosis is reversible and can be paused by forcing on the solution side. |
| Diffusion activity does not gets affected by the solute potential. | Osmosis activity gets influenced by the solution potential. |
| This process depends on free energy of various particles or molecules (pressure potential, water and solute potential) | Osmosis depends on the free energy of rate of reduction of one solvent . |
| After the completion of the process, the concentration of diffusing molecules gets equalized. | After the completion of the process, the concentration of the solvent is not equalized. |
| Diffusion is not effected by the turgor pressure. | Osmosis, is effected by the turogur pressure as it created the hinderance of the solvents in the cell. |
| Diffusion of any spray into the air will get spread easily into the near by environment. | Cellular waste being moved out of the cell by the water molecules. |
The two are the vital activities occurring in inside the cell, and are considered as the significant one to observe in the field of chemistry and biology to know the exact chronology of the reaction and other work going in and out of the cell.
