MCB 2000 Lecture Notes - Lecture 5: Antimicrobial Resistance, Gram Staining, Prokaryotic Large Ribosomal Subunit
Document Summary
Prokaryotes: genetic material not enclosed with a membrane, absence of other membrane-enclosed organelles, cell division by binary fission, small; <1. 0-3. 0 um in diameter. Inner pair anchored to the plasma membrane: bacterial movement, rotation of flagella, counter-clockwise - swims forward, clockwise - tumble, fimbriae and pili. Other types of microbial motility: gliding motility: diatoms, cyanobacteria, twitching motility, use of pili (type iv pili, pilus extension; pilus binding to a substrate; and forceful pilus retraction (the power stroke) Appendages for attachment - fimbriae: sticky, proteinaceous, projections, used by bacteria to adhere to, each other, a host, surfaces in the environment, may be hundreds per cell and shorter than flagella, serve an important function in biofilms. Bacterial surface coating - glycocalix: protect cells from drying out, slime layer: loosely attached to the cell surface; water soluble, capsule - tightly bound to the cell surface. In gram negative bacteria, the flagellum is attached to the cell vis basal body.
