Using the words hypertonic, hypotonic, and equilibrium correctly , predict what happens when, A) A living cell is placed into fresh water and B)A different living cell is placed into salt water.
To predict what happens when a living cell is placed into fresh water (A) and when a different living cell is placed into salt water (B), we need to understand the concepts of hypertonic, hypotonic, and equilibrium.
A) When a living cell is placed into fresh water, which is typically hypotonic compared to the cell's cytoplasm, the following can be predicted:
- Freshwater has a lower solute concentration than the cell's cytoplasm.
- As a result, water molecules will move from an area of lower solute concentration (freshwater) to an area of higher solute concentration (inside the cell).
- This causes water to enter the cell, resulting in the cell swelling or potentially bursting (lysis) if there is no mechanism to regulate the influx of water.
- The cell is in a hypotonic solution and is experiencing osmosis, which is the movement of water molecules from an area of low solute concentration to an area of high solute concentration, across a selectively permeable membrane.
B) When a different living cell is placed into saltwater, which is typically hypertonic compared to the cell's cytoplasm, the following can be predicted:
- Saltwater has a higher solute concentration than the cell's cytoplasm.
- Water molecules will move from an area of lower solute concentration (inside the cell) to an area of higher solute concentration (saltwater).
- This causes water to leave the cell, resulting in the cell shrinking or shriveling (crenation) if there is no mechanism to regulate the efflux of water.
- The cell is in a hypertonic solution and is experiencing osmosis, but this time water molecules are moving out of the cell.
In both cases, the movement of water is driven by the difference in solute concentration across the cell membrane. It is important to note that cells have mechanisms to maintain proper water balance and prevent extreme changes in cell volume. These mechanisms can involve specialized transport proteins or structures like ion channels and pumps.