-
What is a virus?
- An obligatory intracellular parasite
- all have a protein coat
- target host cell receptors
-
What is the basic structure determining shape?
- the capsid
- encoded for in the viral genome
- it's composed of repeated protein subunits, minimizing the number of genes requires.
- two main capsid forms: symmetrical and asymmetrical
-
What is the virus protein coat?
-
What determines host range?
- available receptors
- cellular factors
- types of hosts a virus can infect
-
Symmetrical vs Asymmetrical Viruses
- symmetrical: filamentous or icosohedral
- asymmetrical: T4 bacteriophages, poxviruses
-
What occurs in the lytic cycle?
- bacteriphage replicates quickly, killing the host
- the host cell explodes, releasing the bacteria
-
What happens in the lysogenic cycle?
- bacteriphage is quiescent
- integrates into cell chromosome as PROPHAGE
- can reactivate to become lytic
-
What is tranduction?
the mechanism by which DNA moves from one bacterium to another (when a virus takes some of the host DNA with it)
-
-
What are the viral genome types?
- DNA/RNA
- Single/double stranded
- linear/circular
-
What are the three main viral genomes?
- DNA viruses
- RNA viruses
- Retroviruses
-
What are the steps of the animal virus life cycle? (in order)
- Attachment
- Penetration
- Uncoating
- Biosynthesis
- Maturation
- Release
-
What is the DNA life cycle?
- virus enters cell and travels to nucleoid before uncoating
- Uses host polymerase to create RNA template then replicate
-
What is the RNA life cycle?
- RNA genome inserted into host cell
- viral genome replicated using RNA dependant RNA polymerase
- NEVER CONVERTS TO DNA
- lyses host
-
What is the retrovirus life cyle?
- Binds to host then uncoats envelope, sending the capsid into host.
- Uses ITS OWN reverse transcriptase, which creates a DNA copy of the original RNA genome.
- DNA copy is inserted into host genome.
- buds off host, creating envelope
|
|
