Viruses Flashcards
what is viral latency
ability of a pathogenic virus to lie dominant in a cell
On which principle is the Baltimore classification system based?
Method of viral mRNA synthesis
what is a class I virus
dsDNA -
to replicate transcribe DNA into mRNA using RNA polymerase and that mRNA to proteins
example of a class I virus
herpes
What is a class II virus
ssDNA , can be positive or negative
to replicate use DNA polymerase to from dsDNA - transcribed using RNA polymerase - mRNA -translated to protein
example of class II virus
Adeno-associated virus
what is a class III virus
dsRNA
for replication uses positive strand acts as mRNA - translated proteins
example of class III virus
reovirus
what is a class IV virus
ssRNA(positive strand)
for replication - RNA dependent RNA polymerase to replicate ssRNA+ into ssRNA- then back to ssRNA+which goes to ribosomes and is translated
example of a class IV virus
sars or HEP A
what is a class V virus
ssRNA-
replicate - use RNA dependent RNA polymerase to produce ssRNA+ then turned back to ssRNA-which goes to ribosome s to make proteins
example of a class V virus
Influenza or ebola
what is a class VI virus and how does it replicate
ssRNA(+) diploid ( contains 2 copies of positive
to replicate use reverse transcriptase to produce DNA.
DNA/RNA hybrid ,
RNA disintegrates as unstable so left with single DNA strand which is duplicated by DNA polymerase produce dsDNA.
This inserted into host genome using integrase then transcribed to mRNA by RNA polymerase
Example of a class VI virus
HIV
What is a class VII virus and how does it replicate
this is gapped dsDNA
part of genome is double stranded and part single stranded
to repair gaps use DNA polymerase to form dsDNA
this undergoes transcription to produce mRNA to proteins
mRNA can be used to make more class VII molecules by reverse transcriptase. Important as otherwise wouldn’t be enough genomic material for the daughter cells
