lytic

Lytic is an adjective used in biology and medicine to describe processes or agents that cause the destruction or rupture of cells. The root concept is lysis, the disintegration of a cell’s membrane or cell wall, leading to the release of its intracellular contents. Lytic activity can be caused by mechanical, chemical, enzymatic, or biological factors.

In virology, the term is closely associated with the lytic cycle, a viral replication pathway in which a virus infects a host cell, hijacks its machinery, and ultimately causes cell lysis to release new virions. The lytic cycle typically involves adsorption, entry and replication of viral genome, assembly of viral particles, and release through the disruption of the host cell membrane, often aided by viral enzymes such as endolysins and holins. This stands in contrast to the lysogenic cycle, where the viral genome integrates into the host genome and replicates with the host without immediate lysis, potentially switching to a lytic phase under stress.

Lytic activity is also described in bacteriology, where lytic bacteriophages or lytic enzymes specifically degrade bacterial cell walls, causing bacterial cell death. In pathology and physiology, lysis can refer to the rupture of red blood cells (hemolysis) or programmed and accidental cell death mechanisms that involve membrane rupture.

Etymology traces lytic to the Greek lysis, meaning loosening or breaking apart. The term is used across disciplines to denote destructive breakdown of cellular integrity by various agents.