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Flashcards in Intro to Virus Deck (20):
1

What are the 3 typical components of a virion?

1- Nucleic acid (DNA or RNA) Always
2-Protein sheath (Always)
3-Lipid envelope (sometimes)

2

What are the 3 main shapes of a Viral capsid?

1-Icosahedral (spherical)
2-Helical (cylindrical)
3-Complex (Combination of icosahedral and cylindrical)

3

What are the three basic functions of the capsid?

1-Protect genetic material
2-Aid in attachment to cell
3-package viral enzymes

4

Icosahedral viruses are composed of __________ which are made up of 5-6 __________

capsomeres, protomers

5

A viral protein layer found between the capsid and the envelope is called?

Tegument or matrix protein

6

What are the 3 forms viral genetic information is found?

1-positive sense
2-negative sense
3-double stranded/ambisense

7

What are the 7 groups of viruses according to the baltimore system?

1-DNA (+)
2-DNA (+/-)
3-DNA (+/-) RT
4-RNA (+)
5-RNA (-)
6-RNA (+/-)
7-RNA (+) RT

8

The period in which the viral genetic information is "off the radar" and inside the cell is called?

Eclipse phase

9

What are the two kinds of enveloped penetration?

1-Direct fusion (only capsid enters the cell, envelope becomes part of membrane)
2-Viropexis (receptor mediated endocytosis, capside and membrane are brought inside)

10

Instead of being on the envelope surface, cell surface receptors interact directly with what in naked capsid penetration?

The spikes on the capsid

11

Regardless of the type of genetic material, a virus must convert into which form in order to ultimately undergo viral replication and transcription?

mRNA

12

Which type of virus uses host transcription processes to produce mRNA from its template?

DNA virus

13

A series of viral genomes is called what?

Concatemer

14

What two phases might a DNA virus have?

1-Latent phase- dormant
2-Lytic phase- replicating

15

Sequential phase expression of a viral genome is known as?

complex expression (each set of proteins help set up the next set)

16

Which type of virus is directly translated in the cell?

RNA (+) viruses (RNA (-) strand is also made for replication purposes)

17

Which type of virus brings it's own reverse RNA polymerase to convert its anti sense strand into readable form?

RNA (-)

18

The use of reverse transcriptase to convert RNA to DNA and integrate into host genome is typical of which virus type?

Retrovirus

19

Once integrated into the genome and replicated the retrovirus is said to be a what?

provirus

20

Capsid formation, "Encapsidation" favors the incorporation of?

the viral genome