1. EUBACTERIA and ARCHAEBACTERIA pp.360-372

2. Classifying Prokaryotes
All prokaryotes were once placed in the Kingdom Monera.
Recently, biologists divided them into two different kingdoms: the Eubacteria and the Archaebacteria.

3. Eubacteria Archaebacteria
No peptidoglycan in cell walls
Live in extreme environments
Thermophiles, halophiles, methanogens
Peptidoglycan in cell walls
Cannot survive in extreme environments
Bacteria & cyanobacteria
Prokaryotic
No nucleus
Single-celled
Ribosomes
No membrane-bound organelles

4. Archaebacteria 
DNA shows a closer evolutionary relationship to eukaryotes
Many archaebacteria live in extreme environments.
Methanogens live in oxygen-free environments (ex. thick mud & animal digestive tracts)
Halophiles live in salty environments
Thermophiles live in hot environments (ex. hot springs)

6. 2. Eubacteria
Eubacteria have a cell wall that protects the cell and determines its shape.
Live everywhere:
in fresh and salt water
on land
in the human body

7. E. coli, a Typical Eubacterium
(Peptidoglycan)
A bacterium such as E. coli has the basic structure typical of most prokaryotes: cell wall, cell membrane, and cytoplasm. Some prokaryotes have flagella that they use for movement. The pili are involved in cell-to-cell contact. The cell walls of eubacteria contain peptidoglycan.

8. Types of Eubacteria Bacilli = rod-shaped Cocci = spherical-shaped
Spirilla = spiral & corkscrew-shaped
Prokaryotes can be identified by their shapes. Photo Credit: ©David Scharf/Peter Arnold, Inc.

9. Arrangement or Grouping
Paired = diplo
Filamentous (chains) = strepto
Colonial (grape-like clusters) = staphylo

10. Identifying Prokaryotes:
Two different types of cell walls are found in eubacteria.
A method called gram staining tells them apart.
Gram-positive bacteria have thick cell walls with large amounts of peptidoglycan.
Gram-negative bacteria have thinner cell walls inside an outer lipid layer.
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