Biology 1202B Lecture Notes - Lecture 22: Lysogenic Cycle, Lytic Cycle, Galactose
27 Apr 2015
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Document Summary
Bacteriophages: viruses that infect bacteria, much of what we know about viruses comes from the study of bacteriophage, e coli phages, virulent bacteriophages, kill host cell every infection cycle, temperate bacteriophages, enter inactive phase, passed on to daughter cells. Virulent bacteriophage infection: phage is not motile, must randomly collide with appropriate host cell, phage enzyme lysozyme, digests hole in bacterial cell wall, protein remains outside, only dna enters, phage uses host cell transcription and translation machinery, phage contains own polymerase, replication of phage dna. 100 200 copies: phage dna can recombine, high rate of evolution, head and tail, phage proteins synthesized using host transcription translation machinery, phage encoded lysozyme, used to break open cell wall, release progeny phages. Specialized transduction: transfer of bacterial host cell genes, only genes near insertion site can be transferred, gal gene allows bacteria to metabolize galactose o.
