2. Bacteria Dated back about 3.5 billion years ago

3. Bacterial Characteristics zAll prokaryotic zAutotrophic or Heterotrophic zAverage size- 1um -500um

4. Kingdom Archaebacteria

5. Kingdom Eubacteria zPhylum Cyanobacteria zPhylum Cyanobacteria - (blue-green algae) photosynthetic zPhylum Spirochetes zPhylum Spirochetes - Gram negative, spiral bacteria, heterotrophic, move by a corkscrew rotation (Ex.) syphilis zPhylum Proteobacteria zPhylum Proteobacteria - Largest group, Enteric bacteria, chemoautotrophs, nitrogen-fixing bacteria. zPhylum Gram + bacteria zPhylum Gram + bacteria- Have a thick layer of peptidoglycan.

6. Bacterial Shapes zCocci zCocci - round zBacilli zBacilli - rod zSpirilli zSpirilli - spiral Prefixes: zStaphylo zStaphylo-form clusters zStrepto zStrepto - form chains

7. Bacterial Structure zDzD NA (plasmid) zCzC ell Membrane zCzC ell Wall (peptidoglycan) zGzGzGzGlycocalyx - attachment (sticky) zEzEzEzEndospore - tough envelope zCzCzCzCapsule - protection zPzPzPzPili - attachment

8. Bacterial Nutrition zHeterotrophic saprophytes. zHeterotrophic - feed on dead, decaying organic matter, called saprophytes. zPhotoautotrophs zPhotoautotrophs - use sunlight as a source of energy. zChemoautotrophs zChemoautotrophs - use chemical reactions as a source of energy.

9. Bacterial Respiration zObligate zObligate Anaerobes Anaerobes - cannot live in the presence of oxygen. zFacultative zFacultative Anaerobes Anaerobes - can live with or without oxygen. zObligate zObligate Aerobes Aerobes - cannot live in the absence of oxygen.

10. Bacterial Reproduction z Rapid reproduction inhibit z Heat, cold, predators, & lack of food inhibit reproduction. Methods: z Binary fission z Binary fission - asexual z Conjugation z Conjugation - sexual

11. Production of Toxins zPathogen zPathogen - any organism that causes a disease. zToxin zToxin - Poisonous substances that disrupt the metabolism of the infected organism. yEndotoxin yEndotoxin - found in the cell wall yExotoxin yExotoxin - secreted into areas around bacteria.

12. Antibiotics zInhibit growth of some bacteria. zDisadvantages: yDestroy useful bacteria as well. yResistance of bacteria.