Endosmosis vs. Exosmosis

Main Difference

The main difference between Endosmosis and Exosmosis is that Endosmosis is the movement of a solvent across a semi-permeable membrane from a region outside the cell to inside the cell to a lower solute, whereas Exosmosis is the movement of a solvent across a semi-permeable membrane from inside a cell or vessel to outside environment where there is a high solute.

Difference Between Endosmosis and Exosmosis

Comparison Chart

Endosmosis vs. Exosmosis

Endosmosis is a type of osmosis in which solvent molecules enter into the cells of a vessel; on the other hand, exosmosis is a type of osmosis in which solvent molecules towards into the cells or vessel. In Endosmosis, the direction of solvent molecules is towards the vessel or cell, while in exosmosis, the direction of solvent molecules is outside the vessel or cell. Endosmosis carries out by placing cells under hypotonic solutions, i.e., the solutions where there is a high amount of solvent molecules in the solution. However, exosmosis is carried out by placing cells under hypertonic solutions, i.e., solutions with a lower amount of solvents.

In endosmosis, the solute concentrations are higher inside than the surroundings; on the flip side, in exosmosis, the solute concentrations are lower inside than the surroundings. Endosmosis, as carried out in a hypotonic solution, means that solvent potential will be higher in surroundings than inside of the cell, whereas exosmosis, as carried out in hypertonic solution, means that Solvent potential will be lower in surroundings than inside of the cell.

Endosmosis results in swelling at the end as solvent molecules enter the cell from their higher concentrations to a lower concentration, while exosmosis results in shrinking at the end as the solvent molecules exit the cell from a region of higher concentration to the lower concentration. Endosmosis in plants is carried out by the movement of water molecules as absorbed by root cells from the cell; however, exosmosis in plants is carried out by water movement from root hair cells to cortical cells.

Endosmosis, in the case of animals, takes place in freshwater fish that undergo endosmosis, whereas exosmosis is carried out by seawater fish. Endosmosis in humans has significance as they can be water toxified if there is too much endosmosis; however, in case of increased exosmosis, they can suffer from dehydration.

What is Endosmosis?

Endosmosis is the solvent movement across a semi-permeable membrane in one region or area outer the cell where there is a higher solvent inside the cell where this is a lower solute. It is the kind of osmosis that involves passive or submissive water diffusion through a semi-permeable membrane from a high concentration of solvent to a lower concentration of solvent. The inside concentration of the cell is hypertonic in the situation, i.e., there is a lower amount of solvent and is in a high concentration of solute.

It is thus making the outside situation of the cell as hypotonic, i.e., having a lower amount of solute and a higher amount of solvents. Water potential is the tendency of water to move towards lower potential from a higher one and where there is also a higher amount of solute. Thus water moves from higher potential to lower one into the hypertonic environment.

Endosmosis increases the turgor pressure in the cell, and turgor pressure is the pressure exerted on the walls by the inside solution. It occurs as water starts entering the cytoplasm in the cell and causing the cytoplasm to exert pressure on the cell membrane, thus causing the cell to become turgid. This process can considerably cause a cell to swell as more and more water enters. If this same vessel or cell is put in pure water or the concentration of solutes inside the cells is too high, it can make cell swell and lead to the bursting of the cell.

In the case of animals, this process takes place in freshwater fishes. The cells of freshwater fish are hypertonic as compared to their living environment. The surrounding water in which these fish live in a lower concentration of solutes and is hypotonic, which means that fish of freshwater have to osmoregulate to offset for endosmosis through excreting a huge amount of diluted urine.

In humans, Endosmosis is of high importance as it is needed to keep us alive, but an excess of endosmosis can lead to the destruction of a person’s cell and thus jeopardizing their survival. For people who drink too much water can be affected by intoxication or hyponatremia.

What is Exosmosis?

Exosmosis is the movement of a solvent across a semi-permeable membrane from inside a cell or vessel, which is in a higher ratio of solvent to an outside environment where there is a lower ratio of solvent. It is also a type of osmosis that involves passive diffusion of water through a semi-permeable membrane from a high concentration of solvent to a lower concentration of solvent but in the opposite direction of the endosmosis. The inside concentration of the cell in this scenario is hypotonic, i.e., there is a higher amount of solvent and a lower concentration of solute, which makes the outside situation of the cell as hypertonic, i.e., having a higher amount of solute and a lower amount of solvents.

When exosmosis happens, the water moves out of the cell from higher concentration into the external environment of lower concentration. The cell membrane in this process acts as a permeable membrane. If the rate of this process increases rapidly, then too much water from the cytoplasm will flow to the lower concentration, thus leading to the shrinking of cells. This shrinking due to the removal of water from the cytoplasm is also known as plasmolysis. This shrinking of cells can lead to serious damages to the cell.

Exosmosis is carried out by placing cells under hypertonic solutions, i.e., solutions with a lower amount of solvents. As the solute concentrations are lower inside than the surroundings, it results in shrinking at the end as the solvent molecules exit the cell. Exosmosis in plants is carried out by water movement from root hair cells to cortical cells.

In animals, this exosmosis plays an important role. As a saltwater fish (marine) can experience or undergo modifications in ion concentrations in their living environment. The saltwater fish cells are hypotensive in contrast to the outside environment. These fish also osmoregulate to indemnify for exosmosis by the consumption of seawater and excreting a small quantity of water. If we subject a freshwater fish into saltwater, which contains a higher ratio of solutes as compared to their inner selves, they may shrink by the outflow of water from their cells.

In humans, this exosmosis is useful for regulating and retaining the water levels in the body as excessive exosmosis may leading to dehydration as water moves out of the cells. This serious dehydration may also causes death.

Conclusion

Endosmosis is the movement of the solvent the cell membrane from a region outside the cell where there is a higher solvent to inside the cell where this is the lower solute, whereas, Exosmosis is the movement of a solvent across the cell membrane from inside a cell which is in a higher ratio of solvent to outside environment where there is a lower ratio of solvent.