When a cell is placed in a hypotonic solution, the concentration of solutes outside the cell is lower than inside the cell, resulting in a higher concentration of water outside the cell. Due to osmosis, water moves from the hypotonic solution into the cell, causing the cell to swell as it takes in water
. For animal cells, which lack a rigid cell wall, this influx of water can cause the cell to swell and potentially burst (lyse) if the volume increase is excessive
. In contrast, plant cells have a rigid cell wall that limits excessive swelling. When placed in a hypotonic solution, plant cells absorb water, swell, and become turgid (firm), but the cell wall prevents them from bursting
. At the cellular level, swelling can lead to changes in cell shape, formation of membrane blebs, and an increase in cell volume. If the swelling is too great, it may lead to membrane rupture, as observed in some cell types under strongly hypotonic conditions
. However, some cells can survive and recover from hypotonic swelling if the osmotic stress is moderate
. Summary:
- Water enters the cell by osmosis due to lower solute concentration outside.
- The cell swells as it gains water.
- Animal cells may burst if swelling is excessive.
- Plant cells become turgid but are protected from bursting by their cell wall.
- Swelling can cause changes in cell shape and membrane structure.
- Cells can sometimes recover if the hypotonic stress is not too severe.
This process is fundamental to understanding cell behavior in different osmotic environments
