Intro Flashcards
Viruses genome type (general)
Either DNA or RNA (Not Both)
Virus organelles
None
Do viruses contain Muramic acid?
No
Do viruses have ribosomes?
No, mostly.Areanavuris packages ribosomes “accidentally”
Classical virus classification scheme based on what 4 properties?
- Genome type (size, strandedness, shape, +/-, segment)2. Symmetry3. Lipid membrane4. Virion/Capsid size
ICTV classification emphasizes what?
The viral genomeAlso based on viral structure (symmetry, icosahedral, helical, enveloped vs non-enveloped)
Baltimore classification
clusters into family based on the TYPE of genome*complement to ICTV
Baltimore DNA viruses
Groups 1 + 21. +/- dsDNA2. + ssDNA
Baltimore RNA viruses
Groups 3,4,53. +/- dsRNA4. + ssRNA5. - ssRNA
Which type of RNA virus is complimentary to RNA
-ssRNAIt has to create (+) strand to generate mRNA for protein synthesis
Copying of which strand of dsRNA will generate mRNA?
Negative (-) strand
Baltimore retroviruses
Groups 6 + 76. +ssRNA7. +/-dsDNA
RNA viruses typically have a _____ genome
Smallerdue to higher error rate
dsRNA viruses – two properties
One pieceSegmented
DNA viruses single or double stranded?
Both!
Virus genomes are ____ (referring to # of copies). Which virus is the exception?
HaploidRetroviruses (have two copies)
Capsid definition
Protein (VIRAL) shell surrounding the nucleic acid
Nucleocapsid made of…
Capsid + Nucleic Acid
Helical virus capsid is ______ and made of _________?
cylindrical made of capsomere surrounding the RNA
Polyhedral virus capsid components
Capsomere and spikes
Capsid made of ____ proteins
Viral
Capsid is more or less stable than envelope?
More!
Capsid is stable to what things?
- Temp2. pH3. Proteases4. Detergents5. Drying
Viral envelope composed of
Lipid, protein, glycoproteinMembrane from host, proteins from virus
All ____ have an envelope
Negative strand RNA viruses
Glycoproteins in envelope are for…
Viral attachment
Capsid viruses released by…
cell lysis
Enveloped viruses are released by…
either BUDDING or LYSIS
Which type of virus (capsid/enveloped) elicits hypersensitivity and inflammation?
EnvelopedThis causes immunopathogenesis
Naked capsid virus components
Nucleic AcidStructural ProteinEnzymes/NA-binding proteins =Nucleocapsid
Components of Enveloped virus
-Nucleocapsid (NA+Structural/Enzyme Proteins)-Glycoproteins -Membrane
DNA virus categories
-DS-SS Non enveloped-Complex Enveloped
Enveloped dsDNA Viruses
HerpesHepaDNA
Non-Enveloped dsDNA Viruses either…
Circular or Linear
Circular Non-Enveloped dsDNA
PapillomaPolyoma(formerly grouped together as PAPOVAviridae)
Linear Non-Enveloped dsDNA
Adeno
All DNA viruses are _______ except for _______
IcosahedralPoxviruses
RNA Virus categories
ss+ss-ds
RNA virus subcategories
**draw the chart**
Major viral replication steps (5)
- Recognition / attachment2. Penetration / uncoating3. Synthesis of NA and protein -early mRNA synth –Replication —Late mRNA synthesis —-Posttranslational Mod4. Assebly5. Budding (or Lysis)
Growth curve for virus from lysis is…
one step
Steps for one step growth curve
Adsorption/EntryUncoating and Replication (ECLIPSE)MaturationViral Release
During Eclipse period, what happens?
infectivity dissappears
What happens during latent period?
replication of NA and Protein
Attachment requires what process?
Recognition of receptor on host cell (for entry)
Non-Enveloped viruses penetrate by what methods?
Endocytosis (RME)Viropexis (direct)
Enveloped viruses penetrate by what methods?
Fusion (pH dependent)At Low pH – Fusion occurs in ENDOSOMENormal pH – Membrane fusion occurs at surface
