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20 Cards in this Set
- Front
- Back
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What are viruses?
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obligate parasitic organisms that have either DNA or RNA surrounded by a protein coat. They only replicate inside host cells using hosts machinery.
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What are all viruses composed of?
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A nucleocapsid.
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What are the components of the nucleocapsid?
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Capsid,
Nucleic Acid Genome, Integral capsid proteins, encapsidated proteins |
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Integral capsid proteins
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proteins (not capsid) for host recognition or enzymatic function
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Encapsidated proteins
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nucleic acid binding proteins, enzymes (eg. polymerases)
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Some viruses contain an envelope which is:
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a lipid envelope surrounding the nucleocapsid
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Lipid envelope
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derived from host cellular membranes often during exit from the cell. But, Poxviruses make it in the cytoplasm prior to exit.
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Envelope proteins/glycoproteins
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important for host recognition or enzymatic function important for infection
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Matrix protein
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links the envelope and capsid and is between them.
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What are enveloped viruses sensitive to?
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Except for Hep B (which is stable) most enveloped viruses are susceptible to heat, acid, drying, detergents, organic solvents because they disrupt the lipid envelope.
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Enveloped viruses require
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moisture for survival outside the host.
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What are all negative (-) ssRNA viruses?
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enveloped
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Virus family suffix
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viridae
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Virus genera suffix
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virus
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Factors for virus classification
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Nucleic acid type (DNA/RNA)
Structure (size, morph, sym) Replication strategy |
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Genera are based on these properties:
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physical
chemical antigenic |
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Virus type and subtype determined by
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specific serological characteristics.
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Strain designated by
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initials of patient, investigator, place found, or number of isolate.
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(+/-) RNA viruses
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Reo (double capsid, naked)
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+ RNA via DNA
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Retro (enveloped)
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