Virus Life Stages Flashcards
What are the 6 stages of the virus?
Adsorption Penetration Uncoating Replication and gene expression Assembly Maturation Release
Where does the DNA go for replication and gene expression in the infected cell?
Nucleus.
Where does RNA go for replication and gene expression in the infected cell?
Cytoplasm
What may some virions need to mature?
Mature by protease cleavage for activation of surface attachment proteins.
What is the product of lytic infections?
Bacteriophages produce virion particles and result in cell destruction.
What is the product of chronic infections?
Production of bacteriophage virions.
What is the product of lysogenic infections?
Phage replicate with cells without bacteriophage virion particles.
What happens when temperate bacteriophages infect cells, lysogeny?
Infect cell, replicate WITH the bacterial cells and only cause lysis under appropriate conditions - lysogeny.
What is an example of a temperate bacteriophage with lysogeny?
Lambda phage
What are phages that take part in lysogeny called?
Temperate phage or prophage.
Why is the lytic phage important in the environment?
- kills both and solubilise host bacteria.
- plays a major role in carbon recycling within the environment.
What does the establishment of lysogeny depend on?
- the genotypes of both the phage and of the host bacterial cell.
- the physiological status of the bacterial host cell
- phage concentration.
Herpes simplex virus and HIV are examples of what type of virus life cycle?
Quiet latent infection, stay dormant for a long time before becoming lytic at a later stage.
Hep B and C are examples of what kind of virus life cycle?
Chronic or long term infection, released virus particles can go on to infect long term - liver for example where there is lots of replication. This slowly causes instability in the genomic DNA, slowly developing the infections.
What is tumour cell division an example of with relevance to to virus life cycle?
some viruses produce oncogenic developments in a cell such as a tumours, examples: HPV. High risk types affect cervical mucosa- cervical cancer.
