Why is a virus not a cell?
Cannot reproduce outside a living host cell b/c uses its enzymes, atp, ribs
Why are intracellular parasites?
must be inside a cell in order to make more of themselves
Structural characteristics of all viruses
small, capsid, nucleic acid
structural characteristics of some viruses
size of viruses
smaller than prokaryotes
outer shell of virus that is made up of proteins.
how many sides do most viruses have?
20 sides, icosahedron
nucleic acid in all viruses
DNA or RNA, if genome is RNA then the RNA strand contains the genes
surrounds capsid, comes from host cell plasma membrane and buds out of cell
embedded in envelope, coded by viral genes
enzymes in some viruses
carried in capsid with nucleic acid. coded by viral genome