Bacteria

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Bacteria

• What you dont know CAN hurt you!

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(Bacteria Review) What do you already know about
bacteria??
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• Major Episodes in the History of Life

Millions of years ago
Major Episode
475 570 1,000 1,700 2,500 3,500 4,500
Plants and fungi colonize land All major animal
phyla established First multicellular
organisms Oldest eukaryotic fossils Accumulation
of atmospheric 02 Oldest prokaryotic
fossils Origin of Earth
Visual Summary 15.1
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• Two types of Prokaryotic organisms Eubacteria
  (bacteria) and Archaea

Prokaryotes
Domain Bacteria
Domain Archaea (e.g., extremophiles)
Visual Summary 15.3
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• Prokaryotic and eukaryotic cells differ in
  several respects

Prokaryotic cell
Nucleoid region
Eukaryotic cell
Nucleus
Organelles
Figure 4.4
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SUMMARY OF KEY CONCEPTS

• The Two Major Categories of Cells

Visual Summary 4.1
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Review of Prokaryote Structure

• Plasma membrane
• Outer cell wall
• Big loop of DNA
• Little loops of DNA (plasmids)
• Ribosomes
• Cytoplasm

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Generalized structure of bacteria cell
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Figure4.5x2
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Whats going on?
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Detriments to Humans

• Bad breath, tooth decay
• Food poisoning
• Some are pathogenicpathogenic
• Some diseases caused by bacteria
• Strep throat, staph infection
• Cholera, The Plague, anthrax
• Syphilis, gonorrhea,

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How cure bacterial infections?
(Antibiotics)
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HomeworkShould we drop bacteria bomb?

• Are there benefits to bacteria that outweigh
  their detriments to humans?

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Benefits of Bacteria

• Decomposers! ? chemical cycling
• Cyanobacteria were original producers of oxygen
  atmosphere ? ozone
• Origins of mitochondria chloroplasts
• Aid humans in digestion (E. coli)
• Allow cows to digest cellulose (grass) ? milk,
  ice cream, hamburgers!
• Lactic acid fermentation (yogurt, buttermilk,
  sauerkraut)
• bioremediation
• Nitrogen fixers (to be explained in Unit IV!)

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End