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24 Cards in this Set
- Front
- Back
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functions of the capsid
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1. PROTECTS genome against inactivation by nucleases
2. carries VAP 3. antigenic characteristic 4. structural symmetry 5. packaging essential enzymes |
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examples of symmetry
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1. cubic: adeno viruses and herpes virus
2. helical: myxo and rhabdoviruses 3. complex: pox |
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examples of defective virus
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AAV
hepatitis D virus (needs hep B) |
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host must provide virus with:
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1. energy producing system
2. protein synthesizing machinery 3. low molecular weight precursors for synthesis of viral proteins and nucleic acids |
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the temperate phage may result in a lytic or lysogenic cycle depending on :
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1. the conditions of infection (actively replicating or not)
2. genetic constitution of the phage ie of the repressor gene is expressed early or not |
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examples of bacteriophage with
1. dna 2. ss RNA |
1. T phages
2. F2 |
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why doesnt the virus get attacked by bacterial endonucleases
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DNA is different
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difference between bacteriophage replication and general virus replication
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no uncoating
release is always by lysis in bacteriphage replication |
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DEFINITION of lysogenic cycle
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lysogeny is the property of producing phage without infection with external mature phage particles
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properties of repressor protein
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1. blocks the expressor of other phage genes
2. blocks the detachment of the prophage 3. inhibits replication of the new vegetative phage (superinfection immunity) |
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difference between immunity and resistance
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resistance is due to failure of adsorption (extracellular)
immunity is intracellular |
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what could induce a lytic cycle
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UV light, X ray, N2 mustard ...
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what is the difference between transductino adn lysogenic conversion?
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in lysogenic conversion, the phage is a donor while in transduction it is a carrier
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all dna viruses are double stranded except?
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parvovirdidae
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all dna viruses replicate in the nucleus except
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poxviridae
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all rna viruses are single stranded except
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reoviridae
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most rna viruses replicate in the
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cytoplasm
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example of a naked icosahedral dna virus
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parvoviridae
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example of an enveloped icosahedral dna virus
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herpesviridae
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example of a complex dna virus
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poxviridae
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example of a naked icosahedral rna virus
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reoviridae
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example of an enveloped icosahedral rna virus
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togaviridae
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example of an enveloped icosahedral rna virus
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togaviridae
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example of a helical rna virus
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bunyaviridae
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