Plasmolyse

By Plasmolyse in cell biology the contraction of the Zentralvakuole of a vegetable cell is understood with simultaneous separation of the Plasmalemmas about the cell wall. Around this tooreaches, must one the cell to a Plasmolytikum expose. With this it concerns a highly concentrated solution, which contains plentifully salts or sugar components and thus more possesses solved particles than the Zellsaft of the Vakuole. In this case water flows out of the Vakuole on osmotic wayby the diaphragms (Tonoplast, Plasmalemma) into the surrounding, more concentrated medium, so that the cell juice area becomes smaller and separates the plasma hose sticking at the Vakuole with Plasmalemma from the cell wall. During small wall adhesion of the plasma the separation takes place roundish (Konvexplasmolyse), during strong wall adhesionform bizarre forms, in which the plasma is taken off to thin threads (Hecht threads) (Konkavplasmolyse). This procedure is reversibly, thus reversible over the Deplasmolyse =Ursache (presupposed, the cell did not take damage by an excessive Plasmolyse).

= - the Osmvon cells or fabrics a highly concentratedSalt solution, then becomes detached already after short time of the Protoplast (=lebender part of the cell) of the cell wall. The Vakuole becomes smaller, until the Protoplast separates and abkugelt completely from the cell wall.A cause:The water within the cell is less strongly concentrated, than thatWater outside. Such unequal weights resemble themselves in nature (if possible!) automatically out. Water diffuses thus from the cell plasma and the Zellsaftvakuole outside. The mainspring of this concentration reconciliation taking place here is the Brownian molecular movement.

Reconciliation comes now particularly by diffusing waterby the cell membrane. This is only possible everything, because bio diaphragms are permeable for solved materials particularly for water, but not. One says, the diaphragm is semipermeable (as description of model: “halfpermeable”) and/or. selectively permeabel (actual condition, because: only for certain materials permeable).

The hypotonische(thus less loosened particles contained) solution in the cell loses water, there the water particles outward into the hypertonic one (more highly concentrated) solution diffuses. With the acceptance of the solved water particles the Vakuole and the Cytoplasma shrink inside the cell.

The taking place diffusion of water throughone calls a semipermeable diaphragm also osmose. This term designates a one-sided diffusion. A comparison to understand: If one evaporates to water in the pot, a lime (salt) forms for lining at the soil. If one already takes a short while before however the pot from the stove, is the remaining water muchmany more salzhaltiger than the origin water.

From this follows: The water delivery of the cell (with the Plasmolyse) increases the salt concentration in reality within the cell, which adapts itself thus to the external medium in the concentration (and this is diluted additionally by the water flowing out of the cell) thatProcedure is reversible; if one puts the cell into pure water, then this diffuses back into the cell and dilutes there the solution: Deplasmolyse.

Ways both solutions, external medium and cell inside, the same concentration solved material up, then it concerns isotonische solutions, thus solutionssame concentration.

Web on the left of

video of the Plasmolyse of a red bulb cell