BIOL 2051 Study Guide - Chronic Wasting Disease, Lipid Bilayer, Scrapie
Document Summary
Viroids and prions: viroids, rna without capsid (viruses without capsids) Infect plants: prions, protein-only infectious agent, bse (mad cow), scrapie (sheep), creutzfeld-jakob, kuru (humans), chronic wasting, defective protein causes normal protein to take on abnormal shape, loses normal disease (deer, elk) function. Virus structure capsids: capsid- protein surrounding nucleic acid, capsid are arranged to give virion symmetry. Icosahedral capsids (poliovirus, herpes virus: roughly spherical. Long tube of protein, with genome inside: tube made up of hundreds of identical protein subunits, tube length reflects size of viral genome. Complex capsids: mixture of icosahedral & filamentous shapes, many bacteriophage (viruses that infect bacteria) Asymmetrical shapes: tend to be larger viruses, poxviruses. Includes genes encoding viral proteins: capsid, envelope proteins if virus is enveloped, any polymerase not found in host cell. International committee on taxonomy of viruses classification system based on: genome composition. Classified by baltimore method: capsid symmetry. Presence or absence of host derived envelope: size of virus particles, host roange.
