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BS 1040: Cell Biology > viruses > Flashcards

Flashcards in viruses Deck (12)
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1

in which direction does positive sense viral RNA go?

5'-3'

2

in which direction does negative sense viral RNA go?

3'-5'

3

what implication does the polarity of negative sense viral RNA have?

a positive RNA must be produced from an RNA-dependent RNA polymerase prior to translation

4

what is meant by monocistronic?

mRNA that can only encode for one polypeptide per RNA molecule

5

what is an issue with for DNA viruses entering eukaryotes?

eukaryotes can only translate monocistronic messages, viruses are polycistronic

6

how do viruses overcome the necessity for a monocistronic message?

-making a cleavable polyprotein
-have a different message for each protein
-make sure there are internal initiation sites

7

why is +ve sense vRNA directly infectious?

it has the same polarity as mRNA

8

what is meant by the term 'directly infectious'?

does not require viral proteins for infection

9

what is meant by subgenomic monocistronic mRNAs when referring to calicivirus?

the virus makes 3 different mRNAs for all 3 proteins by differential splicing of one pre-mRNA strand

10

what is a polyprotein?

a large protein that is cleaved into separate smaller proteins with different biological functions

11

what is the purpose of a double stranded replicative intermediate in negative sense viral RNA?

a template for further replication

12

what is the difference between segmented and multipartite genomes?

segmented genomes have 2 or more pieces of nucleic acid in the same particle whereas multipartite contains each segment in a different particle