
Cytolysis, or osmotic lysis, occurs when a cell
bursts due to an
osmotic 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. 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
A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mech ...
prevents the membrane from bursting, so cytolysis only occurs in
animal and
protozoa
Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histo ...
cells which do not have cell walls. The reverse process is
plasmolysis.
In bacteria
Osmotic lysis would be expected to occur when bacterial cells are treated with a hypotonic solution with added
lysozyme, which destroys the bacteria's cell walls.
Prevention
Different cells and organisms have adapted different ways of preventing cytolysis from occurring. For example, the
paramecium uses a
contractile vacuole, which rapidly pumps out excessive water to prevent the build-up of water and the otherwise subsequent lysis.
See also
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Cell disruption
*
Crenation
Crenation (from modern Latin ''crenatus'' meaning "scalloped or notched", from popular Latin ''crena'' meaning "notch") in botany and zoology, describes an object's shape, especially a leaf or shell, as being round-toothed or having a scalloped ed ...
*
Lysis
Lysis ( ) is the breaking down of the membrane of a cell, often by viral, enzymic, or osmotic (that is, "lytic" ) mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a ''lysate''. In molecular bio ...
*
Osmotic pressure
Osmotic pressure is the minimum pressure which needs to be applied to a solution to prevent the inward flow of its pure solvent across a semipermeable membrane.
It is also defined as the measure of the tendency of a solution to take in a pure ...
*
Plasmolysis
*
Water intoxication
References
*{{cite book
, last =McClendon
, first =Jesse Francis
, title =Physical Chemistry of Vital Phenomena:
, publisher =Princeton University Press
, year =1917
, location =Original from the University of California
, url =https://archive.org/details/bub_gb_BZUaAAAAIAAJ, quote =Cytolysis -wikipedia.
, doi =
, page
240pages
Cell biology
Membrane biology
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