May 20, 2011

Incipient Plasmolysis

The point at which the plasmolysis is just about to happen, i.e. the plasma membrane start pulling away from the cell, is called incipient plasmolysis. At incipient plasmolysis the protoplast has just ceased to exert any pressure against the cell wall, so the cell is flaccid.

Distilled water have higher water potential than the contents of the cell. If a plasmolysed cell is placed in distilled water, the water enters the cell by endosmosis, volume of the protoplast increases and it begins to exert pressure against the cell wall of plant cell. The pressure exerted by the protoplast against the cell wall is called pressure potential. As the pressure potential of the cell increases due to endosmosis the cell becomes turgid. Full turgidity is achieved when the cell is placed in distilled water.

The turgid animal cells burst in a solution of higher water potential, due to lack of cell wall. The animal cells use the mechanism of osmoregulation to maintain the amount of water and salts in their cells to a constant or nearly constant level.

2 comments:

  1. incipient plasmolysis is half of the process of full plasmolysis, isn't?

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