General Concepts
What is the lysogenic cycle?
A type of temperate phage replication where viral DNA integrates into the host genome and remains dormant instead of immediately killing the host.
What happens during attachment in the lysogenic cycle?
The virus binds to specific receptors on the host cell membrane.
What is site specific recombination?
The precise process where viral DNA is inserted into a specific site on the host chromosome using enzymes.
What happens during the replication stage of the lysogenic cycle?
The host cell divides and replicates both its own DNA and the prophage DNA.
What is a temperate phage?
A bacteriophage capable of choosing between the lytic and lysogenic cycles.
Why does attachment ensure infection occurs only in susceptible cells?
Because only cells with the matching receptors can bind to the virus.
What happens to the host cell after viral DNA integrates?
It remains alive and functional and continues normal cellular functions while the viral DNA stays dormant.
What is the result of host cell division during lysogeny?
Each daughter cell inherits a complete copy of the viral DNA.
What is the viral DNA called after it integrates into the host DNA?
A prophage.
What part of the virus enters the host cell?
The genetic material enters while the viral capsid (protein coat) remains outside.
What enzyme allows viral DNA to integrate into the host chromosome?
Integrase.
What can trigger the prophage to leave the host genome?
Environmental stressors like UV radiation or chemical exposure.
How does the lysogenic cycle differ from the lytic cycle?
In the lysogenic cycle, the virus remains dormant within the host’s DNA. In the lytic cycle, the virus immediately replicates and causes cell lysis(destroys bacteria).
What ensures that viral DNA entry is specific and controlled?
Receptor and attachment protein interactions between the virus and host cell surface.
How does integration allow for virus persistence?
Because every time the host divides, the viral DNA is copied and passed on to daughter cells.
What occurs after induction is triggered?
Viral genes are expressed, producing viral proteins and assembling new virions.
Why is the lysogenic cycle advantageous for the virus?
It allows long term survival and replication within host cells without detection or destruction.
Explain how integrase ensures accurate DNA insertion.
Integrase recognizes specific DNA sequences on both the viral and host genomes, cutting and joining them precisely to form the prophage.
What is the final outcome of the induction process?
The host cell undergoes lysis, releasing newly formed viruses into the environment.