1. Lecture #12 Date ________
Chapter 27~ Prokaryotes and the Origins of Metabolic Diversity

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

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

4. Motility 1- Flagella 2- Helical shape (spirochetes) 3- Slime
4-Taxis (movement away or toward a stimulus)

5. Form & Function Nucleoid region (genophore: non-eukaryotic chromosome)
Plasmids
Asexual reproduction: binary fission (not mitosis)
“Sexual” reproduction (not meiosis): transformation~ uptake of genes from surrounding environment conjugation~ direct gene transfer from 1 prokaryote to another transduction~ gene transfer by viruses
Endospore: resistant cells for harsh conditions (250 million years!)

6. Nutrition & Metabolism
Photoautotrophs: photosynthetic; harness light to drive the synthesis of organics (cyanobacteria)
Chemoautotrophs: oxidation of inorganics for energy; get carbon from CO2
Photoheterotrophs: use light to generate ATP but get carbon in an organic form
Chemoheterotrophs: consume organic molecules for both energy and carbon saprobes- dead organic matter decomposers parasites- absorb nutrients from living hosts
Nitrogen fixation: conversion of atmospheric nitrogen (N2) to ammonium (NH4+)
Oxygen relationships: obligate aerobes; facultative anaerobes; obligate anaerobes

7. Prokaryotic ecology
Decomposers: unlock organics from corpses and waste products
Symbiosis~ •symbiont/host •mutualism (+, +) •parasitism (+, -) •commensalism (+, 0)
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)