| Cytolysis | |
|---|---|
 | |
| A red blood cell in a hypotonic solution, causing water to move into the cell. | |
| Specialty | Cell biology |
| Causes | Osmosis |
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Cytolysis, orosmotic lysis, occurs when a cellbursts due to anosmotic imbalance that has caused excess water to diffuse into the cell. Water can enter the cell by diffusion through the cell membrane or through selective membrane channels called aquaporins, which greatly facilitate the flow of water.[1] It occurs in ahypotonic environment, where water moves into the cell byosmosis and causes its volume to increase to the point where the volume exceeds the membrane's capacity and the cell bursts. The presence of acell wall prevents the membrane from bursting, so cytolysis only occurs inanimal andprotozoa cells which do not have cell walls. The reverse process isplasmolysis.
Osmotic lysis would be expected to occur when bacterial cells are treated with a hypotonic solution with addedlysozyme, which destroys the bacteria's cell walls.
Different cells and organisms have adapted different ways of preventing cytolysis from occurring. For example, theparamecium uses acontractile vacuole, which rapidly pumps out excessive water to prevent the build-up of water and the otherwise subsequent lysis.[2]