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Archaea & Bacteria Domains C23, pp

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Presentation on theme: "Archaea & Bacteria Domains C23, pp"— Presentation transcript:

1 Archaea & Bacteria Domains C23, pp461-476
Prokaryotes Archaea & Bacteria Domains C23, pp

2 Prokaryotic facts Most numerous organisms on Earth
Earth’s earliest fossils (3.5 x 109 yrs old) Lack membrane-bound organelles rRNA analysis shows Archaea linked more to Eukaryotes than to Bacteria Generally have cell wall, cell membrane, cytoplasm with ribosomes, DNA, & small ions/ molecules

3 Archaea vs. Bacteria Cell walls DNA Groups
Bacteria have peptidoglycans. Archaea don’t. DNA Archaea have introns. Bacteria don’t. Groups A: Methanogens, halophiles, thermoacidophile B: Bacilli, cocci, spirilla; gram-pos & gram-negative

4 Bacterial Cell Characteristics, p468
Capsule: protects & aids in attachments Cell wall: protects & gives shape Cell membrane: control passage in/out of cells Plasmid: carries genes in small DNA loop Endospore: contains DNA; thick-coated Pilus: attachment during conjugation Flagellum: propels cells Gram-neg outer membrane: deflect antibiotics

5 Bacteria Nutrition, p469 Autotroph Heterotroph
Photoautotroph (uses sunlight; gets C from CO2) Chemoautotroph (gets energy from inorganic cpd; gets Carbon from CO2) Heterotroph Photoheterotroph (uses light energy but get Carbon from other organisms Chemoheterotroph (gets energy & C from other organisms)

6 Prokaryotic Reproduction, p471
Single circular loop of DNA is copied Binary fission yields 2 identical daughter cells Exchanging DNA Transformation Gets DNA from its outside environment Conjugation Gets DNA from other prokaryote via sex pilus Transduction Virus copies piece of host DNA & transfers it to others

7 Prokaryotic Habitats, p470
Obligate anaerobes = no O2 allowed Facultative anaerobes = + O2 is OK Obligate aerobes = O2 necessary Psychrophilic = cold-loving (0oC – 20oC) Mesophiles = average (20o-40oC) Thermophiles = hot-loving (45o- 110oC) Acidophiles = pH at or below 6.0 Most prefer neutral pH range of 6.5 – 7.5

8 Bacterial disease, p472 Disease Bacterium Anthrax Botulism Tetanus
Cholera Gonorrhea Dental caries Food poisoning Lyme disease Bacterium Bacillus anthracis Clostridium botulinum Clostridium tetani Vibrio cholerae Neisseria gonorrhoeae Streptococcus mutans Salmnella typhimurium Borrelia burgdorferi

9 Bacteria in Industry Foods Medicine Agriculture
Fermentation  buttermilk, sour cream, yogurt Cheeses, sauerkraut, pickles, kimchi, coffee, soy Medicine Acetone, acetic acid, enzymes, antibiotics, insulin Agriculture Endotoxins as insecticides Bioremediation = degrade petroleum


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