When an animal cell or a plant cell is placed in a solution of sugar or salt in water, several important processes occur. Here are the key points to consider for both types of cells:
For Animal Cells:
- Osmosis: Water will move through the cell membrane by osmosis, from an area of lower solute concentration (inside the cell) to an area of higher solute concentration (outside the cell).
- Cell Swelling: If the solution is hypotonic (lower solute concentration than the cell), water will flow into the cell, causing it to swell. This can lead to the cell bursting, a process known as cytolysis.
- Cell Shrinking: If the solution is hypertonic (higher solute concentration than the cell), water will exit the cell, causing it to shrink and potentially become dehydrated, a process known as crenation.
- Isotonic Solution: If the solution has the same solute concentration as the cell (isotonic), there will be no net movement of water, and the cell’s size will remain relatively constant.
For Plant Cells:
- Turgor Pressure: In a hypotonic solution, water will enter the plant cell, causing it to become turgid or swollen. The cell’s central vacuole and cell wall prevent it from bursting.
- Plasmolysis: In a hypertonic solution, water will exit the plant cell, leading to plasmolysis, where the cell membrane pulls away from the cell wall. This causes the cell to become flaccid and can ultimately lead to wilting.
- Isotonic Solution: In an isotonic solution, the plant cell will be in a state of dynamic equilibrium, with water movement in and out of the cell balanced, maintaining its usual turgor pressure.
The effects of placing a cell in a sugar or salt solution depend on the tonicity of the solution (relative solute concentration) compared to the cell. In general, hypotonic solutions cause cells to swell, hypertonic solutions cause cells to shrink, and isotonic solutions result in a stable cell size. For plant cells, the presence of a cell wall and central vacuole plays a critical role in maintaining turgor pressure and cell structure.