Osmosis in living cells : Elodea
Answers to questions
Explain (in terms of water potential) the observations made when the Elodea was placed in a salt solution.
When the Elodea was placed in the salt solution, the vacuoles disappeared and the protoplasm came away from the cell wall making the organelles appear to be clumped in the middle of the cell. Such cells are said to be plasmolyzed. This occured because the water potential inside the cells was greater than that of the salt solution. As a result, water moved out of the cells (primarily out of the vacuoles) and into the salt solution.
What would happen to an animal cell subjected to similar conditions?
An animal cell does not have a cell wall. Therefore, if it were placed in a hypertonic solution it would lose water and shrivel.
What happens if the plasmolyzed cells are placed in distilled water?
If the Elodea cells are placed in distilled after the cells have been in the salt solution the position of the organelles will depend on how long the cells were in the salt solution. If permanent damage was done, the organelles will remain in the center of the cells. If there was no permanent damage, water will reenter the cells, the vacuoles will reappear and the organelles will return to the periphery of the cells.