Bacteria

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Bacteria
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Bacteria Characteristics

• Tiny (10,000 could fit across fingernail)
• Prokaryote
• Heterotrophs or Autotrophs
• Unicellular
• Asexual Reproduction

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Bacteria Shapes

• Bacillus rod shaped
• Coccus spherical
• Spirillum spiral

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Bacterial Structure
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Endospores

• Thick walled structure surrounding chromosome and
  bit of cytoplasm
• Enables bacteria to survive harsh conditions

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Ways to Classify Bacteria By Cell Wall
Differences

• Gram Positive These have thick peptidoglycan
  cell wall which retains purple dye(ex. Cocci)
• Gram Negative Thinner outer layer of
  peptidoglycan, purple dye rinses off, pink (ex.
  Bacilli)

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Ways to Classify Bacteria By Mode of Nutrition

• Photosynthetic Bacteria - autotrophs, obtain
  energy from sun ex. Cyanobacteria
• Chemoautotrophic Bacteria - autotrophs, obtain
  energy from electrons from chemicals. Play role
  in N cycle
• Heterotrophic Bacteria- Feed on organic material,
  with fungi, principle decomposers

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Binary Fission

• Loop of DNA replicates
• Cell splits in half

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Genetic Transfer

• Transformation - DNA absorbed into bacteria from
  environment (dead cells)
• Transduction-Virus transfers DNA from one
  bacteria to another
• Conjugation-Bacteria of two different types get
  close, transfer DNA through tube

Which one is this?
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Differences Between Bacteria and Eukaryotes

• Bacteria
• No nucleus
• 1 micron diameter
• Unicellular
• Single circular loop of DNA
• Binary fission

• Eukaryotes
• Nucleus
• 10-400 microns diam.
• Some multicellular
• Linear DNA, integrated with protein
• Mitosis