BIOL241 Lecture Notes - Lecture 5: Tobacco Mosaic Virus, Symmetry, Restriction Enzyme
Document Summary
Bacteria-bacteriophage interactions: virus genetic element contain rna or dna that replicates in cells but is characterized by having an extracellular state. Can be single stranded or double stranded. Many bacteriophages have a dsdna genome: viruses (virons) metabolically intert; contain nucleic acid surrounded by protein capsid and sometimes other macromolecular components (envelope) Have narrow host ranges envelope studded with viral proteins (ex. influenza virus) tobacco mosaic virus (tmv) has a helical symmetry small. Importance of the bacteria-phage interaction: potential controller of microbial population sizes, may influence phenotype of host prokaryote, phage-host prokaryote interaction has been exploited in molecular biology. Quantification of bacteriophages by plaque assay: holes in petri dishes are plaques, all the bacteria have been killed due to a virus particle. General steps in virus replication: phage lytic cycle attachment specific interaction between viral protein(s) and specific receptor on host cell surface.
