Lytic cycle

The lytic cycle (/ˈlɪtᵻk/ LIT-ək), is one of the two cycles of viral reproduction, the other being the lysogenic cycle. The lytic cycle results in the destruction of the infected cell and its membrane. A key difference between the lytic and lysogenic phage cycles is that in the lytic phage, the viral DNA exists as a separate molecule within the bacterial cell, and replicates separately from the host bacterial DNA. The location of viral DNA in the lysogenic phage cycle is within the host DNA, therefore in both cases the virus/phage replicates using the host DNA machinery, but in the lytic phage cycle, the phage is a free floating separate molecule to the host DNA.

Viruses that only use lytic cycle are called virulent viruses (in contrast to temperate viruses). The lytic cycle is a six-stage cycle. In the first stage, called "penetration," the virus injects its own nucleic acid into a host cell. In some viruses this genetic material is circular and mimics a bacterial plasmid. The virus hijacks the cell's replication and translation mechanisms, using them to make more viruses. Once enough virions have accumulated, specialized viral proteins are allowed to dissolve the bacterial cell wall. The cell bursts due to high internal osmotic pressure (water pressure) that can no longer be constrained by the cell wall. This releases progeny virions into the surrounding environment, where they can go on to infect other cells.

To infect a cell, a virus must first enter the cell through the plasma membrane and (if present) the cell wall. Viruses do so by either attaching to a receptor on the cell's surface or by simple mechanical force.The binding is due to electrostatic interactions and is influenced by pH and presence of ions such as Mg2+ and Ca2+. The virus then releases its genetic material (either single- or double-stranded RNA or DNA) into the cell. In doing this, the cell becomes infected and can also be targeted by the immune system.

...
Wikipedia