1. The Concentration Gradient:
* Inside the cell: The cell's cytoplasm contains dissolved solutes (like salts, sugars, and proteins).
* Outside the cell: Pure water has a very low solute concentration. This creates a concentration gradient, where the solute concentration is higher inside the cell than outside.
2. Water Movement:
* Osmosis: Water naturally moves across semi-permeable membranes (like the cell membrane) from areas of high water concentration (low solute concentration) to areas of low water concentration (high solute concentration).
* In this case: Water will move from the outside of the cell (pure water) into the cell's cytoplasm, attempting to equalize the solute concentration.
3. The Consequences:
* Cell Swelling: As water rushes into the cell, the cell will swell. This is because the cell membrane is flexible, allowing it to expand.
* Possible Lysis: If the osmotic pressure becomes too high (meaning the water influx is too significant), the cell membrane might not be able to withstand the pressure and could rupture, a process called lysis.
4. Factors Influencing the Outcome:
* Type of Cell: Animal cells are more susceptible to lysis than plant cells. Plant cells have a rigid cell wall that can resist pressure from water influx, preventing lysis.
* Solute Concentration Inside the Cell: Cells with a higher internal solute concentration will experience more significant water influx than those with a lower concentration.
In summary: Dropping a cell into pure water causes osmosis, where water moves into the cell to equalize the solute concentration. This can lead to cell swelling and potentially lysis, especially in animal cells.
Important Note: While osmosis is a fundamental principle in biology, the actual outcome depends on the specific cell type, its internal solute concentration, and the time it spends in the pure water.
