Ask Difference

Osmosis vs. Plasmolysis — What's the Difference?

Edited by Tayyaba Rehman — By Fiza Rafique — Updated on September 27, 2023
Osmosis is the movement of water across a semipermeable membrane due to concentration differences. Plasmolysis is the shrinking of a plant cell's cytoplasm due to water loss through osmosis.
Osmosis vs. Plasmolysis — What's the Difference?

Difference Between Osmosis and Plasmolysis


Key Differences

Osmosis and plasmolysis are related phenomena observed primarily in cellular biology. Osmosis refers to the passive movement of water molecules through a semipermeable membrane, usually in response to concentration gradients. On the other hand, plasmolysis occurs when plant cells lose water via osmosis, leading the cell membrane to pull away from the cell wall.
In the process of osmosis, water will move from an area of low solute concentration to an area of high solute concentration. Conversely, plasmolysis becomes evident when a plant cell is placed in a hypertonic solution, causing water to leave the cell via osmosis and leading to the cell's contraction.
Osmosis plays a crucial role in maintaining cellular hydration and nutrient balance. Without osmosis, cells wouldn't be able to regulate their internal environments effectively. Plasmolysis, in contrast, serves as a visual indicator of a cell's water status, revealing the effects of osmotic stress on plant cells.
Understanding both osmosis and plasmolysis is crucial for botanists and biologists alike. While osmosis provides insights into how cells manage water and nutrients, plasmolysis gives a direct view of what happens when plant cells are deprived of water through osmotic processes.

Comparison Chart


Movement of water across a semipermeable membrane
Shrinking of cell's cytoplasm due to water loss

Caused By

Concentration differences
Water loss through osmosis

Results In

Equilibrium in water concentration
Cell membrane pulling away from the cell wall

Observed In

All cells
Plant cells


Maintains cellular hydration and nutrient balance
Indicator of a cell's water status

Compare with Definitions


The passive movement of water across a semipermeable membrane.
Freshwater fish rely on osmosis to regulate their internal salt levels.


The contraction of the cell membrane from the cell wall in plants.
Plasmolysis can be visibly seen when onion cells are placed in a hypertonic solution.


The flow of solvent molecules through a selectively permeable barrier.
Osmosis plays a crucial role in plant root water uptake.


The state of a dehydrated plant cell due to external solute concentration.
Plasmolysis in guard cells results in the closure of stomata, reducing transpiration.


The equalization of water concentration across a membrane.
Dehydration disrupts osmosis, leading to cellular dysfunction.


The process where a plant cell's cytoplasm shrinks due to water loss.
When exposed to saltwater, plant cells undergo plasmolysis.


A biological process governing water movement in cells.
In reverse osmosis, water is purified by forcing it against concentration gradients.


A cellular phenomenon indicating osmotic stress in plants.
In lab experiments, plasmolysis is often demonstrated using salt solutions.


Osmosis (, US also ) is the spontaneous net movement or diffusion of solvent molecules through a selectively permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential (region of higher solute concentration), in the direction that tends to equalize the solute concentrations on the two sides. It may also be used to describe a physical process in which any solvent moves across a selectively permeable membrane (permeable to the solvent, but not the solute) separating two solutions of different concentrations.


The result of osmotic water loss in plant cells.
Prolonged drought can cause plasmolysis in many terrestrial plants.


Diffusion of fluid through a semipermeable membrane from a solution with a low solute concentration to a solution with a higher solute concentration. Osmosis ceases when there is an equal solute concentration on both sides of the membrane.


Plasmolysis is the process in which cells lose water in a hypertonic solution. The reverse process, deplasmolysis or cytolysis, can occur if the cell is in a hypotonic solution resulting in a lower external osmotic pressure and a net flow of water into the cell.


The tendency of fluids to diffuse in such a manner.


Shrinkage or contraction of the protoplasm away from the wall of a living plant or bacterial cell, caused by loss of water through osmosis.


A gradual, often unconscious process of assimilation or absorption
Learned French by osmosis while residing in Paris for 15 years.


(biology) the shrinking of protoplasm away from the cell wall of a plant or bacterium due to water loss


(chemistry) The net movement of solvent molecules, usually water, from a region of lower solute concentration to a region of higher solute concentration through a partially permeable membrane.


(figurative) Passive absorption or impartation of information, habits, etc.; the act of teaching or picking up knowledge incidentally, without actually seeking that particular knowledge.
I was reading about chickens, and I guess I learned about hawks through osmosis.


The tendency in fluids to mix, or become equably diffused, when in contact. It was first observed between fluids of differing densities, and as taking place through a membrane or an intervening porous structure. An older term for the phenomenon was Osmose.


Diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal


The diffusion of water due to concentration differences.
Osmosis ensures that cells maintain an optimal water balance.

Common Curiosities

How is osmosis essential to cells?

Osmosis helps maintain cellular hydration and balances nutrients, ensuring cells function optimally.

Is osmosis exclusive to water?

While osmosis typically refers to water, the concept applies to any solvent moving across a semipermeable membrane.

What triggers plasmolysis in plant cells?

Plasmolysis is triggered when plant cells are in a hypertonic solution, leading to water loss.

Do animal cells experience osmosis?

Yes, animal cells, like all cells, regulate their internal environment through osmosis.

How do plants use osmosis in their roots?

Osmosis drives water uptake in plant roots as water moves from the soil to the roots due to concentration differences.

How does osmosis impact blood cells?

Osmosis can cause blood cells to swell or shrink, depending on the surrounding solution's tonicity.

How can one visually detect plasmolysis?

Plasmolysis is evident when the plant cell membrane contracts and detaches from the cell wall.

What is osmosis?

Osmosis is the passive movement of water across a semipermeable membrane due to concentration differences.

What does plasmolysis refer to?

Plasmolysis refers to the shrinking of a plant cell's cytoplasm due to water loss through osmosis.

Can plasmolysis occur in animal cells?

While the concept is similar, animal cells don't undergo plasmolysis but can lyse or crenate due to osmotic imbalances.

Can plasmolysis be reversed?

Yes, plasmolysis can be reversed by placing cells in a hypotonic solution, causing water to re-enter the cells.

Is plasmolysis harmful to plants?

Prolonged plasmolysis can be detrimental, affecting the plant's metabolic activities and overall health.

Why might a plant wilt due to plasmolysis?

Plants may wilt because plasmolysis reduces their cells' turgor pressure, leading to a droopy appearance.

Can osmosis occur without a membrane?

Osmosis specifically requires a semipermeable membrane to facilitate selective movement based on concentration differences.

How does reverse osmosis differ from osmosis?

Reverse osmosis forces water against its concentration gradient using pressure, purifying it.

Share Your Discovery

Share via Social Media
Embed This Content
Embed Code
Share Directly via Messenger
Previous Comparison
Mossberry vs. Cranberry
Next Comparison
Force vs. Coercion

Author Spotlight

Written by
Fiza Rafique
Fiza Rafique is a skilled content writer at, where she meticulously refines and enhances written pieces. Drawing from her vast editorial expertise, Fiza ensures clarity, accuracy, and precision in every article. Passionate about language, she continually seeks to elevate the quality of content for readers worldwide.
Tayyaba Rehman is a distinguished writer, currently serving as a primary contributor to As a researcher in semantics and etymology, Tayyaba's passion for the complexity of languages and their distinctions has found a perfect home on the platform. Tayyaba delves into the intricacies of language, distinguishing between commonly confused words and phrases, thereby providing clarity for readers worldwide.

Popular Comparisons

Trending Comparisons

New Comparisons

Trending Terms