Replication Flashcards
How do we study the replication of viruses?
In vitro in cell cultures.
Describe what happens to viruses that do not grow in cell culture.
Infectious clones
What are susceptible and permissive cells?
1) viruses can enter the cell
2) viruses can replicate in the cell
What do you measure in the one step growth curve?
The increase in infectious virus is measured over time by titrating and sampling.
What is the eclipse time?
The time between the virus disappearing inside the cell and releasing virions. Eclipse time comes after penetration.
What are the steps in viral replication?
Attachment Penetration Uncoating Transcription Translation Replication Assembly of virions Release
Attachment
Receptors on the viral envelop/capsid become connected to the complementary receptors on the cell membrane.
Viral Penetration
The genome enters the host cell’s cytoplasm.
Enveloped use membrane fusion
Naked use endocytosis
Which polymerase would a DNA virus use if replicating in the host cell nucleus?
cellular DNA dependent RNA polymerase to make mRNA
Which polymerase would a DNA virus use if replicating in the host cell cytoplasm?
viral DNA dependent RNA polymerase
What happens in ss+ RNA viruses during translation?
Because they resemble cellular mRNA, their nucleic acid can bind directly to the cell’s ribosomes, resulting in partial or full translation.
What happens after ss+ RNA viruses translate their mRNA?
After they translate their mRNA, these viruses can then code for their own RNA dependent RNA polymerase to replicate their own genome. GENE
SS - RNA viruses must carry their own…?
ENZYME: RdRp
Are retroviruses haploid or diploid?
They are diploid
Meaning behind retroviruses being diploid…
It means there are 2 copies of ss+RNA
