BISC 120Lg Lecture 16: Bacteria
21 Mar 2016
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Document Summary
Motility: taxis - ability to move toward or away from certain stimuli, chemotaxis: moving toward or away from nutrient or other chemical signal, phototaxis: moving based on light intensity. R plasmids: antibiotic resistance: a lot of antibiotics target peptidoglycan. Vertical gene transfer: from one generation to the next. Horizontal gene transfer: across two species that don"t transfer genes by descent. Transformation: incorporate foreign dna and now have different sequence: homologous recombination, mediated by reca, source: cell death. Transduction: movement of genes between bacteria and viruses: bacteriophage injects and takes over host"s machinery, virus" dna degrades host cell"s dna. Conjugation: genetic material is transferred between prokaryotic cells: in bacteria, dna transfer is one way, piece of dna (f factor) is required for production of pili. Pili pulls donor cell and recipient cell together: (sex pilus) F factor as a plasmid: f positive: donor, f negative: recipient. F factor in chromosome: hfr cell. Autotrophs: require co2 as a carbon source.
