When are cells said to be plasmolysed?

Cells become plasmolysed when they are placed in a hypertonic solution (a solution with more solutes than the cell). In this state, the cell loses water through osmosis, causing the cell membrane to shrink away from the cell wall. As a result, the cytoplasm shrinks, turgor pressure is lost, and the cell turns flaccid.

Step-by-Step Process of Plasmolysis:

1. Hypertonic Environment- The cell is placed in a solution with a higher solute concentration than inside the cell.
2. Water Movement- Water moves out of the cell by osmosis, from higher water concentration inside the cell to lower water concentration outside.
3. Cytoplasm Shrinkage- As water leaves, the cytoplasm and cell membrane shrink.
4. Separation from Cell Wall- The shrinking cell contents (protoplast) pull away from the rigid cell wall.
5. Flaccid State- With the loss of water, turgor pressure drops to zero. The cell becomes soft and cannot push against its wall.

Key Features of a Plasmolysed Cell:

• Membrane Separation: The plasma membrane detaches from the cell wall.
• Shrunken Protoplast: The cytoplasm contracts and pulls inward.
• Loss of Turgor Pressure: The cell becomes weak and flaccid instead of firm.