1. Chapter 27~Prokaryotes and the Origins of Metabolic Diversity

2. Classification l Kingdom: Monera? l Domain: Bacteria l Domain: Archaea l Shape cocci (sphere) bacilli (rod) helical (spiral)

3. Structural characteristics l Cell wall~ peptidoglycan (sugars & proteins); √ Gram +: w/peptidoglycan penicillin action √ Gram -: little peptidoglycan, lipopolysaccharides; most pathogens; impede drug action l Capsule: adherence; protection l Pili: adherence; conjugation

4. Motility l 1- Flagella l 2- Helical shape (spirochetes) l 4-Taxis (movement away or toward a stimulus)

5. Form & Function l Nucleoid region (genophore: non- eukaryotic chromosome) l Plasmids l Asexual reproduction: binary fission (not mitosis)

6. l “Sexual” reproduction (not meiosis): l transformation~ uptake of genes from surrounding environment conjugation~ direct gene transfer from 1 prokaryote to another transduction~ gene transfer by viruses l Endospore: resistant cells for harsh conditions (250 million years!)

7. Nutrition & Metabolism l Photoautotrophs: photosynthetic; harness light to drive the synthesis of organics (cyanobacteria) l Chemoautotrophs: oxidation of inorganics for energy; get carbon from CO2 l Photoheterotrophs: use light to generate ATP but get carbon in an organic form

8. l Chemoheterotrophs: consume organic molecules for both energy and carbon saprobes- dead organic matter decomposers parasites- absorb nutrients from living hosts l Nitrogen fixation: conversion of atmospheric nitrogen (N2) to ammonium (NH4+) l Oxygen relationships: obligate aerobes; facultative anaerobes; obligate anaerobes

9. Prokaryotic ecology l Decomposers: unlock organics from corpses and waste products l Symbiosis~ symbiont/host mutualism (+, +) parasitism (+, -) commensalism (+, 0) l Disease opportunistic: normal residents of host; cause illness when defenses are weakened Koch’s postulates: criteria for bacterial disease confirmation exotoxins: bacterial proteins that can produce disease w/o the prokaryote present (botulism) endotoxins: components of gram - membranes (Salmonella)