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Prions,Viroids,Virus
Microbiology - Prions, Viroids, Viruses
Question | Answer |
---|---|
Prions, Viroids, Viruses | missing link btwn non-living & living b/c don't have all characteristics of living; lack ability to reproduce on their own; are infectious agents & reproduce inside host cells; obligate intracellular parasite |
Prions | proteins, smallest disease agent; linked to Creutzfeld-Jakob Disease (mental degeneration), Kuru-Canabalism; Bovine Spongiferous Encephalitis (Mad Cow Disease); Scrapie (Sheep Disease) |
Prions | Creutzfeld-Jakob Disease |
Creutzfeld-Jakob Disease | Mental Degeneration |
Prions | Kuru |
Kuru | Cannibalism |
Prions | Bovine Spongiferous Encephalitis |
Bovine Spongiferous Encephalitis | Mad Cow Disease |
Prions | Scrapie |
Scrapie | Sheep Disease |
Prusiner | 1997 Nobel prize - Scrapie |
Viroid | made up of RNA; causes only plant diseases |
Viruses | made up of at least capside (protien) & 1 of 4 kinds of Nucleic Acid |
4 kinds of Nucleic Acid | Double Stranded DNA & RNA, Single Stranded DNA &RNA |
Viruses | some contain envelope |
Viruses | Are genetic parasites |
Genetic parasites | Depend on host metabolism for reproduction |
Polio virus | only virus capable of reproduction w/o intact host cells |
Venter | 2003; synthesized 'A' phage (bacterial virus) |
Smallest Virus | Enteroviruses 30nm |
Largest virus | Orthopox 300nm |
Shape of Viruses | Helical, polyhedral - iscosa hedral, Complex - bullet shaped; Spherical - enveloped |
1st virus to be indentified | Tobacco Mosaic Virus (TMV) |
TMV | filterable agent |
Beijerinck (1899) | characterized them as infectious |
Stanley (1935) | crystallized TMV; 1st observed virus TMV |
viral replication | lytic & lysogenic cycles in phages |