Viruses Flashcards
DNA Viruses: Name Them
Mnemonic = HHAPPPPy Hepadna* Herpes* Adeno Pox* Parvo Papilloma Polyoma
*Enveloped
DNA Viruses: Characteristics
All double-stranded (except parvo, which is SS)
All linear (except papilloma, polyoma and hepadna, which are circular)
Are icosahedral (except pox, which is complex)
Replicate in nucleus (except pox, which carries own DNA-dependent RNA pol and replicates in cytoplasm)
What is special about the herpes viruses envelope?
Gets its envelope from nuclear membrane of host. Unique as most enveloped viruses get their envelope from the plasma membrane as they exit the cell.
Which viruses are enveloped?
Think about which are naked (non-enveloped).
Mnemonic for non-enveloped/naked = give PAPP smears and CPR to a naked HEPpy Papilloma- Adeno- Parvo- Polyoma-
Calici-
Picorna-
Reo-
Hepe-
Rest = enveloped with plasma membrane. Herpesvirus is exception in that it is enveloped with nuclear membrane.
What is the only double-stranded RNA virus we need to know for boards?
Reovirus. Other RNA viruses are ss.
The important reovirus you should know about is rotavirus.
What is the difference between positive and negative sense ssRNA?
Pos sense = mRNA is like ours and can be directly translated into protein in cytoplasm
Neg sense = complementary to our mRNA, and must be copied into pos sense mRNA before it can translated into protein. Note: converting from neg sense to pos sense requires RNA-dependent RNA polymerase that isn’t found in humans. Virus must bring it with.
Which viruses are positive sense ssRNA?
Mnemonic = i went to a RETRO TOGA party where i drank FLAVored CORONA and ate HEPpy CALIfornia PICkles
Retro- Toga- Flavi- Corona- Hepe- Calici- Picorna-
Which viruses replicate in the nucleus?
Which viruses replicate in the cytoplasm?
All DNA viruses replicate in the nucleus, except pox virus which replicates in the cytoplasm.
All RNA viruses replicate in the cytoplasm except influenza and retroviruses, which replicate in the nucleus.
Which viruses are negative sense ssRNA?
Mnemonic = Always Bring Polymerase Or Fail Replication Doofus Arena- Bunya- Paramyxo- Orthomyxo- Filo- Rhabdo- Delta- (doofus/defective virus in that it requires HBV co-infection to replicate)
*These viruses must bring their own RNA-dependent RNA polymerase (convert to +ve sense RNA first and then use host machinery to translate)
Which are the picornaviruses?
Mnemonic = PERCH Polio- Echo- Rhino- Coxsackie- Hepatitis A-
Which are the paramyxoviruses?
Mnemonic = PaRaMyxovirus
Parainfluenza
RSV (tx with Ribavirin)
Measles, Mumps. Note: rubella is togavirus
What viruses are the hepatitis viruses A -> E?
HAV: Picorna- HBV: Hepadna- *Only DNA hepatitis virus HCV: Flavi- HDV: Delta- HEV: Hepe-
