Viruses Flashcards
Virus
infectious particle of genes packaged in a protein coat
Different genome shapes
Double-stranded DNA/ Single-stranded DNA
Double-stranded RNA/ Single-stranded RNA
Single linear/ Single circular / Multiple pieces
Capsid
protein shell enclosing the viral genome
capsomere
protein subunit of a capsid
Rod-shaped
helical virus
Polyhedral
icosahedral virus
Complex
icosahedral head + helical tail
Envelope
membrane derived from host cells that surround many animal viruses
An envelope is made of
Phospholipids & membrane proteins from host cells, Glycoproteins and enzymes of viral origin
Obligate intracellular parasite
can only replicate inside a host cell
Viruses lack enzymes for ____
making macromolecules
Host range
limited # of species a virus can infect
Host range is controlled by __
Lock & key fit of viral surface proteins and receptors on host cells
West Nile Virus
infect mosquitoes, birds, horses, and humans
Measles affect
humans
Bacteria virus
Phage
Lytic cycle
replicative cycle that ends in death of host cell
Virulent phage
ex. E.T4 phage
virus that is replicated by a lytic cycle