LQB292 Lecture Notes - Lecture 3: Chromosome, Generation Time, Geobacillus
Document Summary
Size: varies by microbe, diameter: 0. 2 to 1um. Shape: coccus (p: cocci) - sphere, bacillus - rod/ cylindrical, spirochaetes - spiral, pleomophic (more than one shape, arrangements, coccus (single), diplococci (pair), streptococci (chain), staphylococci (clusters, bacillus (single), diplobacilli (pair), palisades, nomenclature, genus then species, latin names. Genus species: write the full name first then abbreviate after that, e. g. E. coli: escherichia coli (e. coli, coli described habitat (colon, staphylococcus aureus, describes the gold coloured (aureus) colonies. Structures: single celled, no nucleus, no defined organelles, cytoplasm, 80% water, 20% protein, carbs, lipids and salts, capsule, prevents desiccation (drying, attachment to surface/ cells, biofilm formation. Located under the cell wall: phospholipid bilayer, transport, cellular respiration, cell wall synthesis, enzyme/toxin secretion, taxis (movement) Lipid a (endotoxin) + o-polysaccharides (antigenic determinant: thin peptidoglycan layer, gram stain, crystal violet. Forms crystals with cv inside cells: alcohol wash [ethanol] (decolouristion, g+ stays purple, g- goes colourless. Safranin (counterstain: will stain the g, p. i. e. s, e. g.
