Life Cycle of Bacteriophage.
Bacteria eating virus is called bacteriophage. Life Cycles:
There are 2 types of lifecycles that occur in the bacteriophage: 1) Lytic Cycle
2) Lysogenic Cycle
1) Lytic Cycle:
In lytic cycle, virus that is the bacteriophage causes lysis of the host cell. It is virulent phage. 2) Lysogenic Cycle:
In lysogenic cycle, the bacteriophage does not cause lysis of host’s cell. It is avirulent phage.
Landing, Penetration and Attachment
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 using tail fibers. Attachment is done with the help of receptors. Control
The virus then releases its genetic material (either single- or double-stranded RNA or DNA) into the cell. In doing this, the cell is infected and can also be targeted by the immune system. This relation is called master-slave relation. Biosynthesis
The virus' nucleic acid uses the host cell’s machinery to make large amounts of viral components. For DNA viruses, the DNA transcribes itself into messenger RNA (mRNA) molecules which are afterwards used to control the cell's ribosomes. The first polypeptides that are translated destroy the host's DNA. In retroviruses , an enzyme called reverse transcriptase translates the viral RNA into DNA, which is then translated again into RNA. Assembly
New viruses are formed by the assembly of the different parts of the virus. After approximately 25 minutes, 200 new viruses are formed. Release
Bacterial cell burst and the newly formed viruses are released from the host cell. Now, they are ready to attack new bacteria.
The first step of lysogenic cycle is landing of the virus on the host’s cell. This is done by tail fibers....
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