Bacteria

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Bacteria

• Appeared 3.5 billion years ago

Size

• Most Bacteria are between 1-10 ?m
• Micrometer micron 1/1,000,000
• Human and plant cells are 10-100 ?m

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Size
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Structure

• Prokaryotic do not have a nucleus (still have
  DNA)
• Have cell wall and cell membrane

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   Movement of Bacteria

• Most have no ability to move (Non-motile)
• Some have flagella and spiral forward

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Bacterial Shapes

• Spherical or round - Cocci

• Rod - Bacilli

• Spiral - Spirilla

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Bacterial - Arrangements

• Singular - Mono

• Pairs - Diplo-

• Chains - Strepto-

• Clusters - Staphylo-

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Reproduction

• Binary Fission
• Main method of reproduction among bacteria
• asexual process (crossing over does not occur,
  genetic changes arise from mutations or viruses)

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Reproduction

• Conjugation
• A way to exchange genetic material from one
  bacteria to another
• Via a sex pilli (extensions of bacteria cell)
• Plasmid (DNA) transferred from one bacteria to
  another

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Energy

• Bacteria obtain energy by
• Photoautotrophs
• Use sunlight like plants
• Chemoheterotrophs
• Use preformed organic molecules like animals

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Habitats

• Archaebacteria - Ancient
• Methanogens - produce methane w/out O2
• Thermophiles - exist in hot environment
• Thermacidophiles - hot acidic environment
• Halophiles - salty environments

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Importance

• Decomposers - breaking down dead organisms
  sewage treatment facilities.
• Food Production - cheese yogurt
• Industrial Uses - oil spills
• Medical Uses - genetic (production of insulin)
• Symbiotic Relationships - organisms existing
  together E. coli essential for the human colon
• Nitrogen Fixation - N2 out of the air converts to
  soil nitrogen for plants

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How They Make You Sick

• Toxins
• Cell Death