Bacteria

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Bacteria
Anabaena is a gram-negative, oxygenic,
photosynthetic, filamentous Cyanobacterium
(prokaryote). The larger cells in the filament
called heterocysts are involved in nitrogen
fixing.
Neisseria gonorrhoeae bacteria that cause the
sexually transmitted disease gonorrhea.
Salmonella
Treponema pallidum is the bacterial pathogen that
causes syphilis. Treponema are flexible,
spiral-shaped bacteria with flagella.
E. Coli
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Life is Everywherereally!
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The Prokaryotes

• Prokaryotes are divided into two kingdoms
• Archaebacteria
• Eubacteria
• Prokaryotes distinguished by lack of nucleus

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Archaebacteria

• May resemble the first living cells
• Live in harsh conditions such as wetlands mud,
  hydrothermal vents, hot springs and exceptionally
  salty water

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Eubacteria

• Includes most pathogenic bacteria
• Have fatty acids in plasma membrane
• Cell walls differ from archaebacteria
• Most widespread and diverse group of prokaryotic
  cells

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Prokaryotic Body Plan
DNA
cytoplasm
plasma membrane
cell wall
capsule
DNA
bacterial flagellum
pilus
plasma membrane
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Binary Fission

• Asexual reproduction
• DNA is duplicated
• Cells split in half
• Only prokaryotes reproduce this way

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Before DNA replication chromosome attaches to
cell membrane
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Membrane growth moves DNA molecules apart
Stepped Art
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Spore Formation

• Asexual reproduction
• Cells become dormant
• DNA and some cytoplasm are encapsulated in a hard
  internal wall

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Conjugation

• Sexual reproduction
• Cells exchange genetic material across a
  cytoplasmic bridge

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Metabolic Diversity

• 3 Classes of bacteria
• Obligate aerobes
• Obligate anaerobes
• Facultative anaerobes

3 Ways to Use Energy

• Photoautotrophs
• Chemoautotrophs
• Chemoheterotrophs

Grouping by energy use or oxygen needs.
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Identifying Bacteria

• Three shapes
• Spherical coccus
• Rod shaped bacillus
• Spiral shaped spirillum
• Four types of motion
• Move by flagella
• Lash, snake, or spiral forward
• Glide slowly on trail of slime
• Do not move at all

Grouping by Shape Motion
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Three Shapes
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THE END