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Archae _amp; Eubacteria

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					Archaea & Eubacteria


    What are bacteria?
                         Mr. C. Sell
What Domain Is It?

 Some group all non-Eukaryotic organisms
  into one “kingdom” – Monera. This is
  outdated and should not be used.
 Others put all non-Eukaryotic organisms into
  two kingdoms: Archae and Eubacteria. This
  is most likely what will be on standardized
  tests.
The Three Domain System
 Most taxonomists today separate all life into 3
  Domains…..
Domain Archaea
Where we might find Archaea




 High temperature
 High sulfur content   Extremophiles
 High pressure
 Highly acidic
Deep Sea Archaeans
Characteristics of Archaea
 Archaea was not recognized as a separate
  taxon until recently (the 1970’s)
 Dr. Carl Woese at the University of Illinois
  discovered that the “extremophiles” were
  genetically very different from the other
  bacteria. Their DNA sequences were very
  different.
 Although Archaeans may look very similar to
  Eubacteria, biochemically and genetically,
  Archaean are as different from Eubacteria as
  they are from humans.
 Although many books and such still refer to
  them as “Archaebacteria,” this term is
  outdated because these organisms are NOT
  bacteria.
Domain Eubacteria
Bacterial Cell Shapes




  Shape of Bacteria/ Naming
  Cocci - sphere
  Bacilli - rods
  Spirilla - spirals
  Staph - in clusters
  Strep - in chains
Images of Eubacteria




Cocci -
Clostridium
Characteristics of Eubacteria
 Bacteria are microscopic Prokaryotic
  organisms.
 Bacteria are the most numerous organisms
  on earth.
 They lack a cell nucleus and are smaller than
  eukaryotic cells.
Movement in Bacteria
 Flagella – a whip like structure that allows the
  bacterium to swim through a medium
 Chemotaxis – response to chemicals
 Phototaxis – response to light
 Magnetotaxis – response to magnetism
Differentiating Among Bacteria

Gram Stain
Gram's Stain is a widely used method of staining
bacteria as an aid to their identification. It was
originally devised by Hans Christian Joachim Gram, a
Danish doctor.
Gram's stain differentiates between two major cell wall
types.

Bacterial species with walls containing small amounts
of peptidoglycan are Gram-negativeBacteria with walls
containing relatively large amounts of peptidoglycan
are Gram-positive.
Gram Negative v. Gram Positive




  Gram Negative            Gram Positive
  Escherichia coli,      Staphylococcus epidermidis,
  Salmonella typhi,      Streptococcus pyogenes, and
  Vibrio cholerae and    Clostridium tetani
  Bordetella pertussis
Gram Staining Process
Bacterial Reproduction

        Occurs by binary fission - one cell splits into
        two cells, offspring are genetically identical to
        parent

        Bacterial conjugation - a form of sexual
        reproduction where bacteria exchange genetic
        information before dividing, offspring have new
        genes (and new traits)
        Transformation - bacteria incorporate genes
        from dead bacteria
        Transduction - viruses insert new genes into
        bacterial cells. This method is used in
        biotechnology to create bacteria that produce
        valuable products such as insulin
Growing Bacteria in the Lab
Examples of Bacterial Diseases
 Streptococcus lactis    strep throat, related bacteria causes necrotizing fasciitis


 Staphylococcus aureas   found on skin, responsible for minor infections (like on cuts/scratches)


 Bacillus subtilis       common lab bacteria, easy to grown, unharmful


 Bacillus tetani         causes tetanus (lockjaw)


 Bacillus botulism       causes botulism (food poisoning)


 Bacillus pestis         causes Black Plague


 Bacillus anthracis      anthrax


 Mycoplasmas             very very tiny, cause of pneumonia



                         link between bacteria and viruses, can't reproduce outside host, causes
 Rickettsia rickettsi
                               Rocky Mountain Spotted Fever



 Escherichia coli        E. Coli - common bacteria of the digestive tract, also causes food poisoning
Summary

 Life is found in three major Domains
                                               Eubacteria

                                 Prokarya
           Archaea




                                               Protista

Possibly                        Eukarya
up to 20                                        Fungi
kingdoms

                     Animalia
                                     Plantae
 Archaea – very ancient single-celled
  organisms. Earliest form of life on earth.
 Prokarya (Eubacteria) – single celled,
  prokaryotic , true bacteria
 Eucarya – Protists, Fungi, Plantae, Animalia.
  These are larger cells, defined nucleus,
  relative newcomers evolutionarily

				
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posted:9/22/2012
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