BSC 242 Lecture Notes - Lecture 4: Osmotic Pressure, Streptococcus, Clostridium
25 Aug 2016
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Chapter 4: functional anatomy of prokaryotic and eukaryotic cells. Prokaryote comes from the greek words for prenucleus. Eukaryote comes from the greek words for true nucleus. Prokaryote: one circular chromosome, not in a membrane. Basic shapes: bacillus (rod-shaped), coccus (spherical), spiral (spirillum, vibrio, spirochete) Anchored to the wall and membrane by the basal body. Pili: facilitate transfer of dna from one cell to another. Polymer of disaccharide: n-acetylglucosamine (nag), n-acetylmuramic acid (nam) Gram-negative cell wall: thin peptidoglycan, outer membrane, periplasmic space. Teichoic acids: lipoteichoic acid links to plasma mebrane/wall teichoic acid links to peptidoglycan. Forms the periplasm between the outer membrane and the plasma membrane. Gram positive: alcohol dehydrates peptidoglycan/cv-i crystals do not leave. Gram negative: alcohol dissolves outer membrane and leaves holes in peptidogylcan/cv-i washes out. Walls of pseudomurein (lack nam and d-amino acids) Protoplasts and spheroplasts are susceptible to osmotic lysis. L forms are wall-less cells that swell into irregular shapes.
