Unit 6

  1. filterable
    • small enough to pass through fine-pored filter
    • important b/c viruses are only active inside host cell
    • ( OIP ) obligate intracellular parasite
  2. OIP
    • obligate intracellular parasite
    • can not replicate unless inside a host and virus benefits from host's harm
  3. Viruses are non-living
    • acellular
    • unable to self-replicate
    • contains no cytoplasm and call membrane
  4. capsid
    • protein coat
    • -helical - hollow cylinder
    • -polyhedral - icosohedral (20 triangular sides) --> capsomeres
    • -complex - bacteriophage
  5. Nucleocapsid
    the genome (nucleic acid) and the protein coat (capsid) of a virus
  6. enveloped virus
    • contains lipid bilayer surrounding the virus capsid
    • - component: from host membrane, lipids, and glycoproteins
    • -properties: environmentally liable
  7. naked virus
    • capsid proteins are exposed to the external environment
    • capsid are responsible for attachment of the virus to the to-be infected cell
  8. Replication of animal virus (lytic cycle)
    • 1. absorption - virus binds to host
    • 2. penetrate - virus injects its genome into host
    • 3. uncoating of envelop and capsid
    • 4. synthesis of viral specific enzymes (early protein)
    • 5. replication of viral genome using the host's cellular machinery
    • 6. synthesis of structural protein (late protein)
    • 7. assembly (maturation) -viral compnents assemble and viruses fully develop
    • 8. release of intact virions - lysis and budding
  9. virion
    a complete virus particle with its DNA/RNA core and protein as it exists outside the cll
  10. oncogenes
    gene that is mutated or expressed at high level and thus helps turn a normal cell into a tumor cell (proto-oncogen)
  11. oncoviruses
    causes cancer
  12. CPE
    • cytopathic effect
    • -degenerative changes in host cell due to infection
  13. latent infection
    persistance of viral genome without viral replication
  14. hemadsorbtion
    • detecting viruses in culture
    • RBC will stick to infected cell surface
  15. hemagglutination
    • detecting viruses in cultures
    • protein binds to RBS and causes to agglutinate
  16. Fourfold
    • viral serology
    • diagnosis of viral disease rely on a fourfold
    • greater increase in antibody titer
    • acute and convalescent --> compare titer
  17. pathogenesis
    • manner in which the disease develop
    • -source, transmission, penetrate, and what does it do the the host
Card Set
Unit 6
characteristics of viruses and lab diagnosis