virus classification structure and replication Flashcards
theories of virus origin
cellular - viruses were once a cellular component
autopoeitic - viruses were once autopoeitic but became dep upon cells to replicate
viruses can be classified based on
virus particle structure genome replication features serology stability
a virus’s nucleocapsid is composed of
DNA/RNA core
protective capsid coating made of proteins
what’s a capsomere
repeating protein subunit of a capsid
some viruses acquire an _____ upon exiting the host. this can be dissolved using a _________
envelope
lipid solvent
how can bacterial genome be arranged?
single / double stranded and RNA or DNA
what’s the difference btween plus sense ssRNA, minus sense ss RNA and ambisense?
plus = can be used directly for prot translation minus = the antithesis of what's needed for prot translation ambisense = can code for different proteins depending on direction it's being read
what do DNA viruses need that RNA viruses don’t?
access to the nucleus
what do RNA viruses need that DNA viruses don’t?
RNA dep. RNA transcriptase,
-ssRNA and dsRNA must bring their own polymerase into the cell (+ssRNA can act as mRNA)
traits of viral receptors
- usually don’t mimic cell receptor’s normal ligands (binds to diff spots)
- typically are spike lke projections on particle surface
- may need a co-receptor
how can we change receptor recognition?
genetic engineering (integrin RGD sequence or pseudotyping particles)
pathways for viral entry
- endocytosis or direct penetration (pores or membrane disruption)
all viruses excpet ______ have to leave the nucleocapsid to be replicated
dsRNA
all viruses need cells _____ to produce proteins w/ no exceptions.
ribosomes
what’s the fate of stuctural vs. non-structural proteins?
structural go into the capsid
non-structural are only in the infected cell
