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39 Cards in this Set
- Front
- Back
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Capsid
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protein coat
repeating protein aggregates (capsomere) resistant to drying, detergent, etc. |
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Genome
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either DNA or RNA
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dsDNA
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most pathogenic
translated/transcribed in host nucleus, EXCEPT poxviruses |
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ssDNA
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1st made into dsDNA
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partially dsDNA
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hepadnaviruses (hep B) ssDNA regions
filled before enter host nucleus |
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dsRNA
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transcribed to +ssRNA and -ssRNA
acts like DNA |
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ssRNA (+)
3 types |
1. positive sense +ssRNA - directly to RNA
2. neg sense -ssRNA - template for +RNA/DNA, ALL ARE ENVELOPED 3. ambisense ssRNA - pos. and neg. on same strand |
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intergral capsid proteins
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not capsid, host recognition or enz fxn
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encapsidated proteins
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nucleic acid binding
enzymes |
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Nonenveloped (naked)
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more resistant to heat, acid, etc
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Enveloped
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lipid envelope around capsid, endocytosed
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Enveloped
1. lipid envelope |
from host membrane during exit of host cell
EXCEPT poxviruses, made before leaving |
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Enveloped
2. envelope proteins/glycoproteins |
for host recognition/enz fxn.
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Enveloped
3. matrix proteins |
structural, link envelope and capsid
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NOTE!
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all -ssRNA viruses are enveloped
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Enveloped
1. lipid envelope - durability |
easily broken, then lose host recognition factors
require moisture for survival |
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Classifications of viruses
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family, genus, type, subtype, strain
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DNA Viruses
1. Enveloped |
Pox - linear
Herpes - linear Hepadna - circular |
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DNA Viruses
1. Naked |
Polyoma - circular
Papilloma - circular Adeno - linear Parvo (ss) - linear |
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RNA Viruses
1. RNA+ |
N: Picorna
N: Calici E: Togo E: Flavi E: Corona |
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RNA Viruses
1. RNA- |
All E
Rhabdo Filo Orthomyxo - segmented Paramyxo Bunya - segmented, some ambience Arena, some ambience |
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RNA Viruses
1. RNA+/- |
N, Double Capsid
Reo - segmented |
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RNA Viruses
1. RNA+ via DNA |
E: Retro
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Steps of Viral Replication (4)
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1. Recognition and attachment
2. Penetration (Ryan's fav.) 3. Transcription/Translation 4. Viral replication |
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Steps of Viral Replication
1. Recognition and attachment |
viral surface proteins
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Steps of Viral Replication
2. Pentration |
energy dependant
non-E - receptor mediated endocytosis or directly E - fuse membranes, capsid enters |
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Steps of Viral Replication
2. Pentration - 4 Mechanisms |
Endocytosis - endosomes
Translocation - entire virion Injection - genes enter only Fusion - of cell membrane and viral envelope |
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Steps of Viral Replication
3. Transcription/Translation |
depends on virus type
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Steps of Viral Replication
4. Viral replication - DNA Virus |
Nucleus:make dsDNA; host transcribes
Poxviruses: in cytoplasm Hepadnaviruses - make RNA, mRNA, full lenght RNA, DNA by RT |
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Steps of Viral Replication
4. Viral replication - RNA Virus |
most in cytoplasm
EXCEPT orthomy and retro |
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Steps of Viral Replication
4. Viral replication - Assembly of Virion and Exit |
1. maturation - package into capsid
2. exit - lysis or budding |
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Viral Genetics
Mutations are due to (3) |
poor fidelity of polymerase
lack of proof reading rapid rate |
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Viral Genetics
Recombination |
intramolecular genetic exchange
PRIMARY METHOD |
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Viral Genetics
re-assortment |
segmented genomes; form hybrid strains upon co-infection of host with different viruses
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complementation
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defective virus rescued by replication of another virus producing missing gene product
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Defective Viruses - Satellite Virus
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lacking step of replication
wild type can help |
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Viroid - plant pathogen
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circular ssRNA, no protien coat
auto-replicable RNA use host RNA poly |
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Virusoid
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ssRNA infecting plants with assistant virus
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Prion
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proteinaceous infectious particle
form of host protein Cretz Feldt Jacob Disease BSE, mad cow |
