Introduction to Viruses Flashcards Preview

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Flashcards in Introduction to Viruses Deck (14)
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1
Q

-What 3 structures can viruses take?

A
  • icosahedral( 20 faces, each of which is an equilateral triangle)
  • Helical (protein binds around DNA/RNA in a helical fashion
  • Complex (neither icosahedral or helical)
2
Q

What is meant by viruses being obligate intracellular pathogens?

A

Can only replicate inside host cell

3
Q

What is meant by tissue tropism?

A

most viruses have a specific host range and only infect specific host cell types

4
Q

How can virus families be classified? (4)

A
  • virion shape/symmetry
  • presence/absence of envelope
  • genome structure
  • mode of replication
5
Q

What structures make up a virion? (5)

A
  • lipid envelope
  • nucleic acid
  • spike projections
  • virion associated polymerase
  • protein capsid
6
Q

What steps are involved in virus replication? (7)

A
  • attachment
  • uncoating
  • replication of genomic nucleic acid
  • protein synthesis
  • virion assembly
  • budding and release
  • maturation
7
Q

How can viruses be transmitted? (9)

A
  • blood-borne
  • sexual
  • vertical
  • faecal-oral
  • droplet
  • airborne
  • close contact
  • vector-borne
  • zoonotic
8
Q

What is the host range for smallpox and measles?

A

only infect humans

9
Q

What can coinfection of human and animal/bird strain in one organism lead to?

A

recombination and generation of a new strain

10
Q

What are 4 consequences of viral infection?

A
  • clearance of virus (with no,short or long term immunity)
  • chronic infection
  • latent infection
  • transformation (long term infection with altered cellular gene expression)
11
Q

What kind of immunity is involved in hepatitis C?

A

no lasting immunity

12
Q

What kind of immunity is involved in measles?

A

long term immunity

13
Q

Give 3 examples of chronic infections

A
  • HIV
  • hepatitis B
  • hepatitis C
14
Q

Give 2 examples of viruses which exhibit transformation .

A
  • Epstein-Barr Virus

- Human Papillomavirus