A plant cell becomes plasmolysed when it loses water due to being placed in a hypertonic solution. This process leads to a decrease in turgor pressure and the shrinking of the protoplasm.
Understanding Plasmolysis
Plasmolysis is the process where a plant cell shrinks and its protoplasm pulls away from the cell wall due to water loss. This happens when the cell is in a hypertonic environment.
Hypertonic Solutions and Water Loss
A hypertonic solution has a higher solute concentration than the cell's interior. As a result:
- Water moves out of the plant cell through osmosis.
- The cell loses turgor pressure.
The Process of Plasmolysis
The following steps describe how a plant cell becomes plasmolysed:
- Initial State: The plant cell has normal turgor pressure, and the protoplasm fills the cell.
- Hypertonic Environment: The cell is placed in a solution with higher solute concentration outside the cell.
- Water Loss: Water starts moving out of the cell, from a high water concentration to a lower one, via osmosis.
- Turgor Pressure Decrease: As water leaves, the turgor pressure inside the cell decreases.
- Protoplasm Shrinkage: The protoplasm begins to shrink and pull away from the cell wall.
- Plasmolysis: The protoplasm completely detaches from the cell wall, leaving gaps between the cell wall and the membrane.
- Cellular Shrinkage: The cell shrinks and crumples.
Visual Representation
| Stage | Description |
|---|---|
| Initial | Cell with normal turgor pressure. |
| Water Loss | Water moves out of the cell. |
| Protoplasm Shrinkage | Protoplasm starts detaching from the cell wall. |
| Plasmolysis | Protoplasm fully detached, cell shrinks. |
Example
Imagine placing a piece of fresh lettuce in a salty solution. Initially, the lettuce is crisp because its cells are turgid. However, after some time in the salty solution, the cells undergo plasmolysis, and the lettuce becomes limp.
