BIOL 221 Chapter Notes - Chapter 5: Prophage, Lysis, Auxotrophy
Document Summary
Transduction = phages can pick up bacterial genes and carry them from one bacterial cell to another. Lederberg and zinder tested for recombination in salmonella, alleles were all auxotrophic. When either strain plated on minimal medium, no wt cells observed, after 2 strains mixed -> wild type prototrophs appeared. In u tube experiment, agent responsible for gene transfer is the same size/ sensitivity as a phage of salmonella. Virulent phages = immediately lyse/ kill host, cannot become prophage. Temperate phages = stay in host cell for a while without killing it, can exist as prophage. > dna integrates into host chromosome to replicate with it. > sometimes this quiescent phage becomes active, replicates itself, causes spontaneous lysis of host cell. Generalized transducing phages cna carry any part of bacterial chromosome. Specialized transducing phages = carries only certain parts of bacterial chromosome. When donor cell is lysed by phage, bacterial chromosome broken up into small pieces.
