1. Chapter 18.2: Archaebacteria and Eubacteria
AE/P/FPA

2. Brief Comparison Archaebacteria Both Eubacteria
-Cell wall has no peptidoglycan
-has a unique DNA
-Prokaryotic
-Unicellular
-autotrophic and heterotrophic
-cell wall has peptidoglycan
-heterotrophic photosynthetic (cyanobacteria)
-heterotrophic chemosynthetic (nitrogen-fixing bacteria)

3. Bacteria Structure
Same as most prokaryotic cells and it has a cell wall
Cell wall is important because it prevents bacterial cell from bursting
Most cells naturally take on water by osmosis; live in a hypotonic solution

4. Bacteria Identification
“Gram-Staining”
Reflects a difference in cell walls (they also will react to different antibiotics)
Gram positive = turns purple when stained
Gram negative = turns pink when stained

5. Bacteria Identification
Shape
1. spheres = “cocci”
2. rods = “bacilli”
3. spirals = “spirilla”
Good example of all 3 shapes can be seen in Fig of our textbook

6. Bacteria Identification
Arrangement
1. Diplo = paired arrangement
2. Staphylo = “grape” like arrangement
3. Strepto = “chains of cells” arrangement

7. Bacteria Reproduction
Asexual reproduction
“binary fission”
Sexual reproduction
“ conjugation” with the use of a PILUS (“pili” = plural form)
Fig and 18.14

8. Bacteria Reproduction: Binary Fission vs. Conjugation

9. Other terms to be familiar with
Obligate Anaerobes
One of the first bacteria to evolve
Killed by oxygen
Release energy using fermentation
Obligate Aerobes
Require oxygen for respiration
Release energy using cellular respiration

10. Bacteria Survival Mechanism
Endospore
A tiny structure that contains a bacteriums DNA and a small amount of its cytoplasm, encased by a tough outer covering the resists temperature extremes and harsh chemicals
Protects the DNA during “hard times”
Botulism can be caused by an endospore of B. botulinum germinates

11. Bacteria Survival Mechanisms
Toxin
Poison produced by a bacterium

12. The Importance of Bacteria
Nitrogen fixation
Taking nitrogen from atmosphere and putting it into a form plants can use
Recycling of nutrients (decomposers)
Foods and medicines
Bacteria cause Disease
Now due to development of better antibiotics, the average human life expectancy has increased to 75 years old

13. TODAYS ASSIGNMENT Homework over the weekend:
18.2 Reinforcement and Study Guide
My suggestion is that you complete it here while you have 30 minutes left in class.