MICR 221 Lecture Notes - Lecture 6: Teichoic Acid, Glucosamine, Gram Staining

• School: Queen's University
• Department: Microbiology and Immunology
• Course: MICR 221
• Professor: Virginia K Walker

Document Summary

Procaryotic cell wall shape maintaining protection against osmotic lysis contributes to pathogenesis site of action of many antibiotics: knowledge about assembly important in design of new antibacterial agents. Procaryotic wall types: bacterial, a) gram positive cytoplasmic membrane plus electron dense thick layer (20-80nm) Peptidoglycan, teichoic acids: b) gram negative. Cm plus thin peptidoglycan plus a outer membrane (lps, proteins, phospholipids: mycoplasmas: no cell wall cause pneumonia a little bit more resistant to osmotic lysis, archaea (halophiles, thermoacidophiles, methanogens, diversity of walls, no peptidoglycan! Mechanism of gram stain related to wall types spheroplast vs protoplast. Gram negative cell envelope thin peptidoglycan wall outer membrane coming out of the outer membrane are strands called lipopolysaccharide. Outer membrane chemically distinct from the cytoplasmic membrane barrier to keep periplasmic proteins from diffusing away relatively permeable to small hydrophilic molecules, pores so components can pass through toxic properties.