Viruses Flashcards
1
Q
Describe the general structure of a virus.
A
Viruses are very small infectious particles consisting of nucleic acid enclosed in a protein coat (capsid) and, in some cases, a membranous envelope derived from the host cell.
2
Q
Describe the general life cycle of a virus.
A
- Attachment
- Penetration
- Uncoating
- Transcription/Translation
- Genome replication
- Assembly
- Release
3
Q
How do viruses replicate?
A
Retroviruses integrate a DNA copy of their RNA genome into the host cell
4
Q
Why/how do viruses break the central dogma of molecular biology?
A
- Viruses rely on host cell machinery
- Do not have their own ribosomes or the ability to produce energy
- outside cells they are essentially inert macromolecules
5
Q
What are some of the morphologies of virus?
A
Spherical, icosahedral, helical, and complex.
6
Q
What is the function of the virus capsid?
A
- Physical damage - shearing by mechanical forces
- Chemical damage - UV irradiation leading to chemical modification
- Enzymatic damage - nucleases derived from dead of leaky cells of deliberately secreted by vertebrates as defense against infection.
