November 23 notes

RNA virus (Not retrovirus)
*RNA copied by RNA replicase, enzyme made by virus, copies RNA —> RNA
*RNA genome translated by host cell rRNA, tRNA, amino acids

e.)Assembly of new virions:
*When viral genes have been expressed (i.e, proteins coded for by genes have been made), viral particles spontaneously form. (Capsomeres aggregate around viral genetic material, glycoproteins, collects on caspomeres.)
f.) i.) Lysis of host cell:
*Cell destroyed, this frees viral particles to infect new cells. (ex: T4 phages & E.coli)
ii.) Budding: Virion uses glycoproteins to grand onto host cell membrane, wrap self in membrane and yank itself away - Most common way of releasing virions from eukaryotic host cells.

V.) Consequences of viral infection on host cells.
a.) Death of Cell:
*Cell directly lysed by virus
*Cell dies not directly because of virus (ex: our immune system kills cells because virally-infected.
*Viral replication taxes cell function seriously enough that cell dies.
b.) Disruption of cell function.
*Cell alive, but unable to do much more than make virions
c.) Transformation of normal cell to cancer cell.
*Transformation:Changes in genetic characteristics of cell
*Example: HPB 16 and 18 —> Infect epithelial cells DNA genome of HPV integrates into host cell DNA and knocks out apoptosis in infected cells. —> Makes cells cancerous.
a.) Animal Cells/Cell culture: Must grow viruses in appropriate host cell

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