Viral replication and taxonomy Flashcards
What are the four components used to classify viruses?
1) Nucleic acids
2) Capsid
3) Envelope
4) Size
What are the 7 DNA viruses?
HHAPPP:
Herpes, Hepadna, Adeno, Pox, Parvo, Papilloma, Polyoma
All DNA viruses are double stranded except?
Except parvo (very simple little guy!).
All DNA viruses replicate in nucleus except?
Pox (very complicated! carries its own DNA-dependent RNA polymerase).
All DNA viruses are icosahedral except?
Pox (complex, big guy). Pox in a box!
All DNA viruses are linear except?
Hepadna (circular, incomplete)
Papilloma and polyoma
All DNA viruses are enveloped except?
Gotta be NAKED to get a PAPP:
Papilloma, Adeno, Polyoma, Parvo
All RNA viruses are single stranded except?
Reoviridae are double stranded.
Which RNA viruses are naked?
“CPR to the naked Hippy!”
Calici, Picornia, Reo, Hepe
Which RNA viruses are icosahedral?
Ds: Reo
+single stranded: Picorna ,Calici, Toga, Flavi,
Which RNA viruses replicate in the nucleus?
Retro and influenza/orthomyx
Which enveloped viruses acquired its virus from NUCLEAR membrane instead of plasma membrane?
Herpesvirus.
What is viral genetic “recombination”
Exchange of genes between 2 chromosomes by crossing over within regions of significant base
sequence homology.
What is viral genetic “reassortment”?
When viruses with segmented genomes (e.g., influenza virus) exchange genetic material.
What is viral genetic “complementation”?
When 1 of 2 viruses that infect the cell has a mutation that results in a nonfunctional protein. The
nonmutated virus “complements” the mutated one by making a functional protein that serves
both viruses.
What is a classic example of viral genetic complementation?
hepatitis D virus requires the presence of replicating hepatitis B virus
to supply HBsAg, the envelope protein for HDV.
What is viral phenotypic mixing?
Occurs with simultaneous infection of a cell with 2 viruses. Genome of virus A can be partially or completely coated (forming pseudovirion) with the surface proteins of virus B. Type B protein coat determines the tropism (infectivity) of the hybrid virus. However, the progeny from this infection
have a type A coat that is encoded by its type A genetic material.
Which vaccinations are live attenuated?
Vaccines for bebes/kids: rotavirus, MMR, chickenpox
Vaccines for everyone: influenza (intranasal)
Vaccines for Scary stuff: smallpox, Sabin’s polio, yellow fever
Which vaccinations contain killed virus?
RIP, Alaska (AK).
Rabies, Influenza (IM), SalK Polio, and Hep A vaccines
What vaccinations contain a subunit?
HBV (antigen HBsAg), HPV (6,11,16,18)
Which RNA viruses are + single stranded?
I went to a retro toga party in California where I drank Corona with hippies and ate flavored pickles. (7 viruses)
Retrovirus, togavirus, Calicivirus, coronavirus, hepevirus, flavivirus, and picornavirus
Which nucleic acids are infectious when isolated?
Those belonging to most dsDNA and + strand ssRNA viruses. Exceptions: poxvirus and HBV.
Which nucleic acids are generally not infectious when isolated? Why not?
Those belonging to neg strand ssRNA and dsRNA. They need polymerases that come with them in the complete virion.
Which RNA viruses are segmented?
Bunyavirus, Orthomyxo, arenaviruses, and Reoviruses
