Plant and Animal Cell Tonicity

When the concentration on the INSIDE of the cell is higher, the water will move into the cell, causing the cell to swell. (Hypotonic)

When the concentration on the OUTSIDE of the cell is higher, the water will move out of the cell, causing the cell to shrink. (Hypertonic)

When the concentration on the inside of the cell is the SAME as the outside, the water will move in and out of the cell, causing no change to the cell. (Isotonic)

A hypertonic solution causes water to move out of the cell and the cell becomes shriveled. Red blood cells develop a star-shaped appearance that resembles a spiked ball (they become crenated).

An isotonic solution does not result in any net movement of water in/out of the cell and so it remains unaffected.

A hypotonic solution causes water to move into the cell. Animal cells do not have a tough cellulose wall and if water continues to move into the cell pressure builds until ultimately the cell bursts (cell lysis)

A hypertonic solution causes water to move out of the cell and the cell membrane tears away from the cell wall in a process called plasmolysis.

An isotonic solution does not result in any net movement of water in/out of the cell, however, a plant cell may become flaccid (wilted).

A hypotonic solution causes water to move into the cell. The cell wall limits the cell’s volume preventing it from bursting. However, the plant cells to become turgid (swollen and firm).