BIOL 2051 Study Guide - Quiz Guide: Virus Classification, Capsid, Poliovirus
Document Summary
General properties of viruses (virions: only replicate inside host, no nucleus, organelles, cytoplasm, viral genomes contain. _obligate intracellular parasite_ made of nucleic acid surrounded by a protein coat. information for taking over host cell information for making viral proteins: capsid, genome replication proteins. Virus structure capsids: capsid- _protein coat surrounding _nucleic acid_ _capsid proteins_ are arranged to give virion _symmetry_ _ocosahedral_ capsids (poliovirus, herpes virus: roughly spherical. Long _tube of protein_, with genome inside: tube made up of 100s of identical protein subunits. _complex_ capsids: mixture of icosahedral & filamentous shapes, many bacteriophage (viruses that infect bacteria) _asymmetrical (irregular)_ shapes: tend to be larger viruses, poxviruses, tube length reflects size of viral genomes (short tube = short genome) Virus structure envelopes: envelope- lipid bilayer around capsid of some viruses, allows fusion to host cell membrane, only occurs if host cell not covered by _cell wall_ _bacteriophages_ are non-enveloped: envelope lipids come from host, not encoded by viral genome.
