4 Virology Flashcards
what does it mean that viruses are obligate intracellular parasites?
- cannot live outside living cellular host
- cannot be treated or cured with existing medical therapies
name 3 hosts for viruses
- plants (variegation)
- animals
- bacteria (bacteriophages
how many cell types do viruses affect?
one specific cell type
what are viroids?
- smallest known pathogens
- naked, circular, single-stranded RNA molecules that do not encode protein yet replicate autonomously when introduced to host plants
a viral particle is a ____
viron
viral structure consists of…
- protein coat
- nucleic acid core
- envelope (occasionally)
what is the effect of a viral envelope?
steals plasma membrane from infected host cell, acting as camouflage from immune system
name 3 ways to replicate viruses
- cell culture
- fertilized eggs
- living animals
the protein coat surrounding the nucleic acid core is called a ____
capsid
each capsid consists of identical protein units called ____
capsomeres
what do capsomeres do to viral structure?
bond together and give capsid symmetry
name 2 basic patterns of virus capsids
- helical symmetry
- icosahedral symmetry
helical symmetry
protein subunits and nucleic acid are arranged in a helix
icosahedral symmetry
protein subunits assemble into symmetrical shell that covers nucleic acid-containing core
what are the 2 nucleic acid cores and forms by which viruses are characterized?
DNA and RNA
(double or single stranded)
