Viruses and antivirals- Lectures Flashcards
Almost all DNA viruses are double-stranded; the only single-stranded DNA virus is _
Almost all DNA viruses are double-stranded; the only single-stranded DNA virus is parvoviruses
Almost all DNA viruses replicate in the _ ; the exception to this rule is _
Almost all DNA viruses replicate in the nucleus ; the exception to this rule is poxviruses
* Poxviruses are too big to get into the nucleus and must replicate in the cytoplasm
Because poxviruses can’t get into the nucleus like other DNA viruses, it needs to bring its own _
Because poxviruses can’t get into the nucleus like other DNA viruses, it needs to bring its own DNA-dependent RNA polymerase to make mRNA in the cytosol
Other DNA viruses rely on host DNA-dependent RNA polymerase
Hepadnavirus is a (DNA/ RNA) virus that uses (own/ host) DNA-dependent RNA polymerase
Hepadnavirus is a DNA virus that uses host DNA-dependent RNA polymerase
* Howevever, it first uses its own reverse transcriptase to go from a partial ds-DNA genome- RNA intermediate –> DNA
All RNA viruses are (ss/ds) except for _
All RNA viruses are single-stranded except for reoviruses
All RNA viruses replicate in the host cytosol except for _ and _
All RNA viruses replicate in the host cytosol except for orthomyxoviruses and retroviruses
Only positive sense RNA viruses can serve directly as mRNA and be translated right away; ds RNA viruses and negative sense ss RNA viruses must carry _ with them to transcribe (-) sense RNA first
Only positive sense RNA viruses can serve directly as mRNA and be translated right away; ds RNA viruses and negative sense ss RNA viruses must carry RNA-dependent RNA polymerase with them to transcribe (-) sense RNA first
Retroviruses are (ds/ ss), (RNA/DNA) and they carry a special _ enzyme
Retroviruses are +ssRNA and they carry a special reverse transcriptase enzyme
What are the 3 steps of reverse transcription?
- RNA dependent DNA polymerase makes a DNA-RNA hybrid intermediate
- RNase degrades the RNA in the hybrid
- DNA dependent DNA polymerase synthesizes the second DNA strand in the cytosol –> now the dsDNA can be transported to the nucleus to be integrated into the host chromosome via integrase
What are the 6 steps of the viral lifecycle?
- Attachment: virus attached to host cell
- Penetration: virus gets into host cell somehow (endocytosis)
- Uncoating: capsid is degraded so that genetic material can is accessible
- Replication: viral DNA goes into the nucleus to be replicated and transcribed; RNA viruses do this in the cytoplasm
- Assembly: packaging of the virions
- Release: viral particles get released into the extracellular fluid
Enveloped and naked/non-enveloped viruses can both use _ mechanism to get into a host cell; however, only enveloped viruses will be able to use _ mechanism
Enveloped and naked/non-enveloped viruses can both use receptor-mediated endocytosis mechanism to get into a host cell; however, only enveloped viruses will be able to use membrane fusion mechanism
Enveloped viruses egress either via _ or _
Enveloped viruses egress either via budding from the plasma membrane or exocytosis
Naked/ non-enveloped viruses egress either via _ or _
Naked/ non-enveloped viruses egress either via cell lysis or exocytosis
Influenza and rhinovirus are examples of _ type infections; they are rapid onset, self-limiting, and quickly cleared by immune system
Influenza and rhinovirus are examples of acute type infections; they are rapid onset, self-limiting, and quickly cleared by immune system
Hep B, Hep C, and HPV are examples of _ type infections; there is a continuous presence of replicating virus
Hep B, Hep C, and HPV are examples of persistent/chronic type infections; there is a continuous presence of replicating virus
Fifth disease (“slapped cheek”) is caused by _ virus
Fifth disease (“slapped cheek”) is caused by parvovirus B19 virus
