1. Viruses and Prokaryotes
Chapter 20
Viruses and Prokaryotes

2. Prokaryotes Unicellular, auto- or hetero- troph, no nucleus
Reproduce by binary fission
Conjugation – how bacteria exchange genetic info

3. Domain Archae
- Kingdom Archaebacteria
- walls lack peptidoglycan
- DNA more similar to eukaryotes
- live in extreme environments

4. 3 types of Archaebacteria
1. Methanogens – produce methane gas, most anaerobic
2. Extreme halophiles – in high salt areas; use it to make ATP
3. Thermacidophiles – in high temps and acidic areas

5. Domain Bacteria
- Kingdom Eubacteria
- walls with peptidoglycan
- larger domain
- found everywhere

6. Eubacteria
- grouped by 2 things
1. shape: - bacillus – rod
- coccus – spherical
- spirallus – spiral, corkscrew

7. 2. Response to Gram Stain:
- Gram positive – purple, retains stain; thicker layer of peptidoglycan
- Gram negative – pink, doesn’t retain stain; thinner layer of peptidoglycan; unaffected by many antibiotics

8. Importance Decomposers Producers Nitrogen fixation
Human uses – foods, break down wastes and poisons in water, produce drugs, etc