BIO 315 Lecture Notes - Lecture 5: Extracellular Polymeric Substance, Teichoic Acid, Lipoteichoic Acid
23 Jan 2020
School
Department
Course
Professor
Document Summary
Lecture #5: bacterial cell structure and staining process, the structure of a prokaryotic cell, glycocalyx, external to the cell wall, viscous and gelatinous, made of polysaccharide and/or polypeptide, two types. Slime layer: unorganized and loose: contribute to virulence, flagella. E. coli o157:h7: axial filaments: also called endoflagella, found in spirochetes, arrangements of bacterial flagella, fimbriae and pili, fimbriae. Hairlike appendages that allow for attachment: pilli, the cell wall. Conjugation pili involved in dna transfer from one cell to another: prevents osmotic lysis and protects the cell membrane, contributes to pathogenicity, made of peptidoglycan (in bacteria) Polymer of a repeating disaccharide in rows : n-acetylglucosamine (nag, n-acetylmuramic acid (nam) Rows are linked by polypeptides: gram-positive cell walls, teichoic acids. Lipoteichoic acid links cell wall to plasma membrane: wall teichoic acid links the peptidoglycan. 2-rings in basal body of flagella; produce mainly exotoxins. High susceptibility to penicillin; disrupted by lysozyme: gram-negative cell walls.
