1. Bacteria

2. Bacteria
Unicellular
Prokaryotes
Cells walls containing peptidoglycan

3. Bacterial Shapes Bacilli: rod shaped Cocci: spherical
Bass-ill-eye
Cocci: spherical
Cox-eye
Spirilla: spiral, corkscrew
Spy-rill-uh

4. What are the differences between eubacteria and archaebacteria?

5. Eubacteria versus Archaebacteria
Cell walls of Eubacteria have lots peptidoglycans (mesh of sugar and amino acids)
Archaebacteria do not
Archaebacteria often live in very extreme environments (hot springs, digestive tracts, Great Salt Lake, etc.)

6. Metabolism Bacteria can be heterotrophic or autotrophic
Remember: autotrophs are not ALL photosynthesizers!
Some are chemosynthesizers (convert carbon into organic compounds)

7. How Bacteria Reproduce: Binary Fission
When a bacterium has doubled in size, it replicates its DNA and divides in half
Sexual or asexual?
Identical or different daughter cells?

8. If bacteria are identical, how do they evolve
If bacteria are identical, how do they evolve? Where does genetic variety come from (besides natural mutation rate)?

9. Genetic Variety in Bacteria
Conjugation: cell-to-cell contact
Transformation: bacterium takes up foreign DNA from surrounding environment
Transduction: DNA is transferred from one bacterial cell to another by a virus

10. Conjugation
A hollow bridge (pilus) forms between two bacteria and genes move from one cell to the other
Increases genetic diversity of a population

11. Conjugation

12. Transformation
Bacteria take in foreign DNA from surroundings and incorporate it into their own DNA
*Remember Griffith’s experiment

13. Transduction
DNA is transferred from one bacterium to another by a virus
When new bacteriophages are made, they may contain a small amount of the host cell’s DNA

14. Benefits of Bacteria Some are producers that undergo photosynthesis
Some are decomposers that break down dead matter to recycle the nutrients
Some convert nitrogen gas to a form that can be used by plants (nitrogen fixation)

15. What are some dangers of bacteria?

16. Dangers of Bacteria Break down cells and tissues for food
Example: Tuberculosis (destroys lung tissue)
Release toxins (poisons) that travel through the body
Example: Streptococcus releases toxins into the blood stream causes strep throat and scarlet fever

17. Bacterial Sexually Transmitted Diseases