BSC 160 1nd Edition Lecture 9 Outline of Last Lecture 1 Antibiotics 2 Gram 3 Gram 4 Cell Wall 5 Archaea Outline of Current Lecture 1 Endospores 2 Flagella 3 Motility 4 Pili Fimbriae 5 Glycocalyx Current Lecture Endospores Form of suspended animation Resistant Cell Structures Heat 100 C Radiation 3x normal Chemicals acids bases organics Desiccation dehydration Can withstand UV light Surface Structures Found outside the cell 1 Flagella Organs of motility Bacterial flagella rotate spin Sperm flagella swim Monotrichous 1 flagella These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Lophotichous Multiple flagella emerging in small bunches from same sight Peritrichous Flagella dispersed all over cell s surface Flagellar Structure Protein flagellin arranged in helix Flagella attached thru hook basal body Gram Gram Chemotaxis Movement toward or away from chemical Positive toward negative away Phototaxis Movement toward or away from lights Positive toward negative away Aerotaxis Bacteria that require oxygen can move toward higher concentration Positivetoward negative away Signal sets flagella into motion clockwise or counterclockwise Counterclockwise movement Run Clockwise movement Tumble Gliding motility Movement across a solid surface Most of the time Gram Mechanisms Pili Cast and reel in Surfactant Changing property between surface propelling bacteria forward Motors Proton gradients Advantages of Motility Chemotaxis phototaxis aerotaxis Pili and Fimbriae External structures bacteria use these for interacting Pili or Pilus Fimbriae or Fimbria both made up of proteins Pili longer less numerous Holding Gram microbes for DNA transfer Fimbriae shorter more of them bristle like Glycocalyx Polysaccharide or protein material covers outside of cell Slime layer loosely associated Capsule More tightly bound Functions Attachment Protection of immune system prevent desiccation hold nutrients create biofilms Quarumsensing See other species and can change DNA Hard to get rid of Structural differences in Archaea and microbial Eukarya
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