1. Bacteria
Chapter 23

2. Bacterial Classification
Section 23.1

3. REVIEW: All Bacteria are Prokaryotes
“Before nucleus”
No nucleus
No membrane bound organelles
Eukaryotes:
“True nucleus”
Have nucleus
Have membrane bound organelles

4. Two Domains of Bacteria
DIFFERENCES BASED UPON RNA MAKEUP
Domain Bacteria
Kingdom Eubacteria
Domain Archaea
Kingdom Archaebacteria
More related to eukaryotes
based upon rRNA & gene comparison

5. 1. Domain Archaea
Lack peptidoglycan (protein-carbohydrate compound) in cell wall
Usually located in extreme conditions like: swamps, salt lakes, and hot springs
Three main types:
A. Methanogens
B. Extreme halophlies
C. Thermoacidophiles
Pyrodictium occultum is a  marine organism commonly found in deep-sea hydrothermal vents.

6. A. Methanogens
Energy source: from converting H2 and CO2 into methane gas.
Live in areas absent of oxygen like swamps, sewage, and intestinal tract

7. B. Extreme Halophiles Salt loving bacteria
Location: anywhere there is a high salt concentrations like the Great Salt Lake and the Dead Sea.
Energy source: salt need for them to make ATP

8. C. Thermoacidophiles hot and acidic enviornments
They are found in such places as acidic sulfur springs, undersea vents (smokers) and volcanoes

9. 2. Domain Bacteria Most abundant domain!
Examples: Cyanobacteria, chlamydia, Lyme Disease, botulism, TB, E. coli, anthrax, nitrogen-fixing bacteria
Classified based on:
Gram stain
Shape
Biochemical properties

10. Gram Stain Gram Positive Bacteria
Simple cell wall with lots of peptidoglycan
Stains purple
Gram Negative Bacteria
Complex cell wall with little peptidoglycan
Stains pink

12. Bacterial Shapes Spirilla (spiral-shaped) Bacilli (rod-shaped)
Cocci (sphere-shaped)
Streptococci – long chains
Staphylococci - clusters

14. Bacterial Groups Proteobacteria Gram-Positive Bacteria Cyanobacteria
Spriochetes
Chlamydia

15. Video 1. Proteobacteria Largest and most diverse group
Many live symbiotically with other organisms
Nitrogen-fixing bacteria
Some cause diseases
Rocky Mountain spotted fever
Stomach ulcers
Foodborne illnesses
Video

16. 2. Gram-Positive Bacteria
Some cause diseases
Strep throat
Botulism (Botox)
Anthrax TB
Leprosy
A few make antibiotics that kill other bacteria

17. 3. Cyanobacteria Undergo photosynthesis for energy
Simplest life requirements
First oxygen-producing organisms on Earth!

18. 4. Spirochetes Gram-negative Spiral-shaped bacteria
Examples: syphilis & Lyme disease

19. 5. Chlamydia Gram-negative Coccoid shaped, no peptidoglycan
Causes a STD that lives inside animals

20. Biology of Prokaryotes
Section 23.2

21. Bacterial Structures
Most bacteria are composed of the following parts:
Outer cell wall
Cell membrane
Internal foldings = thylakoids (photosynthesis)
Cytoplasm
Ribosomes
DNA
Small molecules and ions

22. Endospores Can form in gram + bacteria
Thick-coated, resistant structures
Form when environmental conditions are poor
Resistant to high temp, strong chemicals, radiation, drying, etc.

23. Video Prokaryotic Movement Taxis: movement toward or away from stimuli
Chemotaxis: chemical stimuli
Physical movement aided by flagella or slime
Patterns of movement: wave-like contractions or corkscrew rotation
Video

24. How do bacteria reproduce?
Asexually via….
Binary fission
Budding
permits the development of more complex colonial structures
Binary fission
Budding

25. Genetic Recombination
Three ways that bacteria can exchange and acquire new combinations of DNA
1. Transformation
2. Conjugation
3. Transduction

26. 1. Transformation
When a bacteria takes on DNA from its external environment.
Then this new DNA is substituted into the bacterial DNA

27. 2. Conjugation
When two bacterium bind together and one bacterium transfers genetic information to the other.
DNA channeled through the sex pilus
Video

28. 3. Transduction
Steps:
1. Virus obtains a fragment of bacteria DNA from its host
2. Virus multiplies inside host (replicating the bacterial DNA as well)
3. Virus breaks out of host cell and invades new bacteria
4. New bacterial host will get old host’s DNA via the virus

29. Know these parts of the bacteria!
Cell Wall
Outer Membrane
Cell Membrane
Cytoplasm
Chromosome
Plasmid
Capsule & Slime Layer
Endospore
Pilus
Flagellum
p. 468
Click above for more info!

30. Bacteria and Humans
Section 23.3
Video

31. Bacterial Diseases Pathology – The study of diseases
Pathogens – anything that causes disease
Bacteria
Viruses
Fungi
Protists

32. Cholera attacking a cell

33. Bacterial Poisons Toxins – bacterial poisons that cause disease
Exotoxins – made up of proteins
Secreted by the gram + bacteria to surroundings
Example: tetanus
Endotoxins – made up of lipids and carbs.
Released by dead gram – bacteria
Cause fever, body ache, weakness, and damage

34. Caused by not taking full dose of antibiotics
How to treat diseases…
Antibiotics – fungi or bacteria that combat infection by interfering with various cellular functions
May lead to Antibiotic Resistance
Caused by not taking full dose of antibiotics

35. Emerging Infection Diseases
Zoonosis: a disease that passes from wild animals to humans
Increase due to global travel of humans & destruction of natural habitat
Example: Lyme disease
Other examples
Video

36. Useful Bacteria to Humans
Probiotics- useful bacteria in your gut
Recycle compounds from dead organisms
Create organic compounds
Food production (buttermilk, sour cream, yogurt, cottage cheese, sauerkraut, pickles)
Produce fuels
Insecticides
Bioremdiation: break down pollutants
Video