BIOL-UA 11 Chapter Notes -Tobacco Mosaic Virus, Enterobacteria Phage T4, Viral Envelope
Document Summary
Virus - an infectious particle consisting of little more than genes packaged in a protein coating. Non-living - cannot reproduce or carry out metabolic activities outside of a host cell. Originally thought to be very small bacteria. Beijernick - showed that the agent of tobacco mosaic disease could not be cultivated on nutrient media; proposed a much smaller and simpler replicating particle than bacterium. Able to be crystallized (cells cannot be crystallized) An infectious particle consisting of nucleic acid enclosed in a protein coat and, for some viruses, surrounded by a membranous envelope. Genomes consist of double- and single-stranded dna and rna, depending on type of virus. Virus is classified by it"s nucleic acid (dna vs. rna viruses) Usually a singular linear or circular molecule of nucleic acid. Some viruses have multiple molecules of nucleic acid. Can have four to hundreds or thousands of genes. Capsid - the protein shell enclosing the viral genome.
