MCB 2000 Lecture Notes - Lecture 6: Tobacco Mosaic Virus, Viral Envelope, Regular Polyhedron
Document Summary
History: louis pasteur"s - rabies caused by a living thing proposed the term virus poison. Ivanowski - discovered tobacco plant causing disease is an agents smaller than bacteria. Size: mimivirus 450 nm, herpes simplex 150 nm, rabies 125 nm, hib 110 nm. Viral components: naked viruses, composed of, nucleic acid, protein coat - capsid, enveloped viruses, composed of protein subunits called capsomeres, have the capsid covered with an envelope (lipids, proteins, and carbohydrates) Introduction of nucleic acid into host cell: complex, bacterial viruses - bacteriophages, head-polyhedral, tail - helical, tail fibers. Endocytosis - active process by which nutrients are brought into a cell: cell membrane folds inwards forming a vesicle, vesicle is transported inside the cell, 2. The biosynthesis of rna viruses: different groups of rna viruses have different mechanism of mrna formation, example: retroviridae - hiv, has reverse transcriptase - to produce double stranded dna.
