BISC 303 Lecture Notes - Lecture 13: Virus Quantification, Rna Virus, Plant Virus

• School: Simon Fraser University
• Department: Department of Humanities Biological Sciences
• Course: BISC 303
• Professor: Julian Guttman

Document Summary

Iwanowski & beijernck: found that after filtering through pores that could retain smallest bacteria, filtered extracts from tabaco could transmit disease to other plants, tabaco mosaic virus, began virology. Peyton rous: sarcoma virus, purified virus and it caused disease in chicken. Twort: discovered infectious agents lysed bacteria (bacteriophages) D"herelle: bacteriophage plaque assay, virus composition. Bowen and pirie: tabacco mosaic virus mostly protein and has nucleic acid. Structure: 10-400nm, few to several hundred genes, 4000-500,000 nt, few to 100+ proteins encoded, nucleocapsid core, dna or rna, not both, protein coast that binds nucleic acid, lipid membrane, virally encoded enzymes, overlapping genes, no introns, saves space. Virion = extracellular infectious particle, non replicating. Capsid: protein coat, only few polypeptides, saves space on genome. Protomers: monomers that self assemble to form final capside. Viral capsid: held together by non covalent bonds (easily break apart) Icosahedral: 20 side polygon, 12 vertices, most efficient way to enclose space, complex, vaccinia virus, bacteriophage, combo of symmetries.