Bacteria

• Bacterium


  One of the three domains of life
• Bacteria

  • Some can be extremophiles
  • Made up of a single cell
  • Prokaryotic cell (generally much smaller than eukaryotic cells)
  • Does not have a nucleus or membrane-bound organelles
  • Has ribosomes, cytoplasm, a cell membrane, and nearly all have a cell wall
  • Has DNA (though still double-stranded, is arranged in a circular shape)
  • Can have a flagellum, a capsule, or pili
  • Many have a plasmid (extra DNA)
  • Can exist inside or outside the human body
  • Multiply faster through binary fission
  • Can share genetic material through conjugation
• If a plasmid has a gene that gives resistance to an antibiotic


  It may allow the bacterium that received the plasmid to survive to that antibiotic
• Bacterial Transformation

  1. Bacteria take in DNA from their environment

  2. Scientists can use a stimulus (such as a heat shock) to induce bacteria in a lab setting to pick up genetic material
• Endospores


  • Allow bacteria to be survivors in all kinds of hostile environments
  • Proves importance to proper sterilization processes
• Not all bacteria are harmful as some are beneficial
• Bacteria in your digestive system help break down food and some can produce certain vitamins
• Bacteria have a very important role as decomposers in the ecosystem
• Bacteria have major roles in the nitrogen cycle to fix nitrogen that plants need
• Pathogenic bacteria


  Cause infections in humans
• Antibiotics can treat bacterial infections but do not work on viruses
• Vaccines can prevent many types of both bacterial and viral infections
• Bacteria are visible under a light microscope
• Bacteria reproduce independently of other organisms
• Shapes of Bacteria

  • Cocci (Spherical)
  • Bacilli (Rod-shaped)
  • Spirillum (Spiral-shaped)
• Heterotrophs

  Consume and feed on some organic matter
• Autotrophs


  Make their own food
• Bacterial Conjugation

  A) Bacterium

  B) Donor

  C) Transferosome

  D) Mobile Plasmid

  
• Bacterial Transformation

  A) DNA

  B) Plasmid

  C) ligase

  D) bacterial

  E) Restriction

  
• Endospore Formation

  A) replicated

  B) Membrane

  C) Exosporium

  D) Cortex

  E) Septum

  F) Spore Coat

  G) Mother Cell