DPD for plant cells in hypertonic-hypotonic-isotonic media

Question

Determine the values of DPD for plant cells in hypertonic, hypotonic and isotonic media?

Answer 1

In plant cells in hypertonic medium there is loss of water for the external, SF > 0 (that is, the vacuolar pressure is high since it is concentrated) and TP = 0 (that is, there is no distension of the cell wall as the cellular volume is decreased) therefore DPD = SF. Such cells are termed as plasmolysed cells, condition characterized by the retraction of the cell membrane which detach from the cell wall.

In plant cells in isotonic medium there is no rise of the internal water volume, SF > 0 and TP = 0 (as the cell wall is not distended). The cell membrane faintly touches the cell wall and in this condition the cell is termed as a flaccid cell.

In plant cells in hypotonic medium there is tendency of water to enter, SF = TP (as the osmotic pressure is completely compensated by the distension of the cell wall) and DPD = 0. The cell which has expanded itself to this point is termed as a turgid cell.