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A hypertonic solution has a greater concentration of non-permeating solutes than another solution. [2] In biology, the tonicity of a solution usually refers to its solute concentration relative to that of another solution on the opposite side of a cell membrane ; a solution outside of a cell is called hypertonic if it has a greater ...
The contractile vacuole, as its name suggests, expels water out of the cell by contracting. The growth (water gathering) and contraction (water expulsion) of the contractile vacuole are periodical. One cycle takes several seconds, depending on the species and the osmolarity of the environment.
Plasmolysis is the process in which cells lose water in a hypertonic solution. The reverse process, deplasmolysis or cytolysis, can occur if the cell is in a hypotonic solution resulting in a lower external osmotic pressure and a net flow of water into the cell.
In hypertonic solutions water flows out of the cell and the cell shrinks (plasmolysis). In hypotonic solutions, water flows into the cell and the cell swells ( turgescence ). Osmotic shock or osmotic stress is physiologic dysfunction caused by a sudden change in the solute concentration around a cell , which causes a rapid change in the ...
When a biological cell is in a hypotonic environment, the cell interior accumulates water, water flows across the cell membrane into the cell, causing it to expand. In plant cells , the cell wall restricts the expansion, resulting in pressure on the cell wall from within called turgor pressure .
It occurs in a hypotonic environment, where water moves into the cell by osmosis and causes its volume to increase to the point where the volume exceeds the membrane's capacity and the cell bursts. The presence of a cell wall prevents the membrane from bursting, so cytolysis only occurs in animal and protozoa cells which do not have cell walls.
Thus, the terms ending in -osmotic (isosmotic, hyperosmotic, hypoosmotic) are not synonymous with the terms ending in -tonic (isotonic, hypertonic, hypotonic). The terms are related in that they both compare the solute concentrations of two solutions separated by a membrane.
Osmoregulation is the active regulation of the osmotic pressure of an organism's body fluids, detected by osmoreceptors, to maintain the homeostasis of the organism's water content; that is, it maintains the fluid balance and the concentration of electrolytes (salts in solution which in this case is represented by body fluid) to keep the body fluids from becoming too diluted or concentrated.