Viruses and Prions Flashcards
what are the general properties of a virus?
small size, genome, metabolically inert
what type of genome does a virus have?
RNA or DNA
what does metabolically inert mean in relation to viruses?
do not possess ribosomes/protein synthesis, some have enzymes
what is a virion?
complete virus particle
what is an envelope?
lipid membrane around some viruses
what is a capsid?
protein shell
what are capsomers
protein units that make up the capsid
how is a virus transmitted?
inhalation via respiratory tract, ingestion via gastrointestinal tract, inoculation, congenital (mother to foetus) and sexual transmission
what does inoculation include?
skin abrasions, mucous membranes, transfusion, transplants, injections and bites
what does transformation mean?
cell not killed, changed to cancerous cell
what does latent infection mean?
remains in cell, no obvious effect on cell function
what are the key stages in viral replication?
attachment, penetration, uncoating, synthesis of viral components, assembly and release
what does antigenic drift include?
minor change, point mutations, epidemics and type A,B,C drift
what does antigenic shift include
major change, recombination, pandemics, only A
what are the steps of the chain of infection?
infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host
