Prokaryotes And The Origins of Metabolic Diversity Kingdom Monera.
Chapter 27~Prokaryotes and the Origins of Metabolic Diversity.
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Transcript of Chapter 27~Prokaryotes and the Origins of Metabolic Diversity.
Chapter 27~ Prokaryotes and the Origins of Metabolic Diversity
Classification
Kingdom: Monera? Domain: Bacteria Domain: Archaea
Shape •cocci (sphere) •bacilli (rod) •helical (spiral)
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
Motility 1- Flagella 2- Helical shape (spirochetes) 4-Taxis (movement away or toward a
stimulus)
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!)
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
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)