1. Three Domains of Living Things
Archaea – prokaryotic cells
Eubacteria – prokaryotic cells
Eukarya – eukaryotic cells

2. Kingdom Monera (what we call bacteria)
All are prokaryotic cells
Oldest living organisms
Difficult to classify:
Physiology
Morphology

3. Bacteria have three basic shapes
1) spherical – coccus (cocci)
2)rod-shaped – bacillus (bacilli)
3) spiral – spirillum (spirilli)

4. Arrangements vary : Staphylo – clusters Strepto – filaments or strings
Diplo – two
Tetra – four
Colonies – groups of like bacteria growing together (starting from a single bacterium)

5. Archaebacteria (live in harsh environments)
- methanogens – live in the absence of oxygen
Halophiles
Thermoacidophiles

6. Eubacteria Defined by Gram stain ( + or - )
Gram + = purple ; Gram - = pink
Peptidoglycan layer
Gram + susceptible to antibiotics (produced by some bacteria)

7. Biology of Monerans DNA is circular (a single chromosome) Plasmids
Cell walls; rigid or flexible
Form capsules
Form endospores

8. Bacteria require energy!
Heterotrophs
Autotrophs: photoautotrophs
chemoautotrophs
Respiration: obligate aerobes
obligate anaerobes
facultative anaerobes

9. Bacterial Reproduction (sex!!)
Asexual - Binary fission
Sexual – Conjugation
Transduction

10. Toxin production (pathogen = disease-causing organism)
Toxin – poisonous substance that disrupts metabolism
endotoxin: Gram- cell walls (released when bacteria die); Salmonella spp.
symptoms =
exotoxin: secreted (very potent) i.e. – Vibrio cholerae
Antibiotics – chemicals that inhibit bacterial growth