Viruses/Prions

Question 1

4 components of a virus?

Answer 1

protein, nucleic acids, lipids, sugars

Question 2

What is a virion?

Answer 2

entire virus particle

Question 3

Envelope vs capsid?

Answer 3

envelope = external lipid membrane present in some viruses; capsid = all viruses have it, protein coat

Question 4

What is a nucleocapsid?

Answer 4

some viruses have this special protein coat around nucleic acid

Question 5

What is a capsomer?

Answer 5

Subunit that makes up a capsid

Question 6

Protein coats can be ___ or ___ in shape? Which can hold more nucleic acid?

Answer 6

icosahedral or helical (open); helical has no theoretical limit to amount of DNA that can be packaged

Question 7

mRNA would indicate a _____ sense strand

Answer 7

positive

Question 8

Which sense strand can be immediately made into viral proteins?

Answer 8

positive

Question 9

Which sense strand virus has to bring its own RNA dependent RNA polymerase?

Answer 9

negative

Question 10

Which kind of viruses are more prone to errors, RNA or DNA?

Answer 10

RNA - no proofreading function so more mutable

Question 11

Phases of viral replication kinetics?

Answer 11

Inoculation, eclipse, burst

Question 12

Before uncoating in the cell, a virus must do what?

Answer 12

attach to cell membrane receptor and be taken into cell

Question 13

What kinds of genes do viral genomes not possess?

Answer 13

Genes encoding protein synthesis machinery, energy metabolism, and membrane biosynthesis

Question 14

What are the spikes you tend to see on enveloped viruses?

Answer 14

Glycoproteins that have been encoded in viral genome, can be used for docking to cell

Question 15

GI tract pathogens - enveloped or nonenveloped?

Answer 15

Nonenveloped because acid destroys lipids

Question 16

Naked viruses are more likely to be released in what manner?

Answer 16

Through lysis

Question 17

Which viruses are more sensitive to heat, acids, and drying? Enveloped or naked?

Answer 17

Enveloped

Question 18

5 ways that viruses can be categorized?

Answer 18

Virus family, disease process/site of infection, route of transmission, genome type, ability to establish latency

Question 19

What way of categorizing viruses is most useful for public health measures?

Answer 19

By route of transmission!

Question 20

Epstein Barr is from what family of viruses?

Answer 20

Herpesvirus

Question 21

Are herpesviruses enveloped or naked? What kind of genome do they have?

Answer 21

enveloped; dsDNA

Question 22

“Cold sores” are mostly associated with…

Answer 22

HSV1 (some HSV2)

Question 23

VZV can reactivate as…

Answer 23

shingles

Question 24

Which is more contagious, shingles or varicella?

Answer 24

varicella

Question 25

Which viruses are associated with infectious mono?

Answer 25

Mostly EBV but also CMV

Question 26

Genome of influenza A?

Answer 26

segmented RNA

Question 27

Influenza A - enveloped or naked?

Answer 27

enveloped

Question 28

Why is HIV called a retrovirus?

Answer 28

reverse transcriptase activity; RNA to DNA (integrated) to RNA again

Question 29

2 main prion diseases in humans?

Answer 29

Kuru and CJD

Question 30

Why do prion diseases produce spongiform encephalopathies?

Answer 30

plaque formation/accumulation in brain

Question 31

Transmission of CJD is usually ____ or ____

Answer 31

iatrogenic or inherited