Q. Plasmolysis occur due to
Solution:
Osmosis is a process of movement of a solvent across a semipermeable membrane, from lower DPD to higher DPD. This process was discovered by Pfeffer. When the water moves out of the cell, it is called Exosmosis, which makes the cell shrink. When water moves inside the cell, it is called Endosmosis, which makes the cell swell.
If the concentration of a given solute is higher in the solution, in which the cell is placed, as compared to cell sap, it is called a Hypertonic solution. The cell, when placed in this, tends to lose water and shrink (Plasmolysis occurs).
Plasmolysis is a phenomenon of loss of water, thereby shrinking of protoplasm from the cell wall, which is influenced by Hypertonic solution. When a cell is placed in a Hypertonic solution, since the concentration of solute outside the cell is more, water goes out by osmosis. There are three stages of Plasmolysis (LIE):
A. Limited plasmolysis has Pressure potential equal to zero and the osmotic concentration of cell sap is just nearly equal to external. This cannot be visible, as the protoplasm just begins to shrink.
B. Incipient plasmolysis has negative Pressure potential and the protoplasm withdraws from each corner of the cell wall. The Water potential is equal to Solute potential (i.e. w = s).
C. Evident plasmolysis has further loss of water and shrinking of protoplasm. The cell is now called Flaccid.
If the concentration of a given solute is higher in the solution, in which the cell is placed, as compared to cell sap, it is called a Hypertonic solution. The cell, when placed in this, tends to lose water and shrink (Plasmolysis occurs).
Plasmolysis is a phenomenon of loss of water, thereby shrinking of protoplasm from the cell wall, which is influenced by Hypertonic solution. When a cell is placed in a Hypertonic solution, since the concentration of solute outside the cell is more, water goes out by osmosis. There are three stages of Plasmolysis (LIE):
A. Limited plasmolysis has Pressure potential equal to zero and the osmotic concentration of cell sap is just nearly equal to external. This cannot be visible, as the protoplasm just begins to shrink.
B. Incipient plasmolysis has negative Pressure potential and the protoplasm withdraws from each corner of the cell wall. The Water potential is equal to Solute potential (i.e. w = s).
C. Evident plasmolysis has further loss of water and shrinking of protoplasm. The cell is now called Flaccid.