I. Prokaryotes

Bacilli Cocci Spirilla

A. Characteristics of Bacteria

1. Unicellular- only one cell 2. Prokaryotic- lacks a nucleus and membrane bound organelles.

3. Form

A)Bacillus- rod shaped

B)Spirilla- spiral shaped

C)Cocci- spherical

4. Nutrition

A) Autotrophs- carry on photosynthesis (cyanobacteria: Blue-green algae)

B) Chemotrophs- use compounds of methane, sulfur and iron to produce energy (Some members of the Archaea Domain)

C) Heterotrophs- both saprophytes (decay dead organisms and wastes) and parasites (live off of other living things). Most Eubacteria

5. Movement

A)gliding on slime

B)twisting in a corkscrew fashion

C)Flagella

D)some don't move

6. Ecological Roles

A)Decomposers- decay dead things

B) Pathogens- cause disease

7. Distribution

Everywhere

Lab Conclusion:

1. Where did you expose your petri dish?

2. Why did you think there would be bacteria present there?

3. Was bacteria present?

4. What are the conditions most favorable for bacteria growth.

5. Where can we conclude bacteria lives?

8. Respiration

A) Obligated aerobes- must have oxygen to survive

B) Obligated anaerobes- cannot tolerate oxygen

C) Facultative anaerobes- can use fermentation in the absence of oxygen

9. Reproduction

A) Binary Fission- asexual cell division

B) Conjugation- exchange of a plasmid through a cytoplasmic extension called a sex pili

C) Transduction- bacteria viruses called phages can transfer genetic material from one bacterium to another

D) Transformation- transfer of naked DNA from the environment to a live bacteria

B. Structure of Bacteria

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C. How Bacteria Affect Other Organisms

1. Helpful Bacteria

A) Bacteria in the intestine help digest food

B) Bacteria help in production of cheese, yogurt, sour cream, pickles, and sauerkraut.

C) Bacteria decompose dead organisms

D) Some bacteria help plants by Nitrogen Fixation

2. Harmful Bacteria

A) 5% of bacteria are Pathogens - disease causing organisms

B) Disease is caused by attacking cells directly or the production of toxins- poisons

3. Protection against bacteria

A) Antibiotics- chemicals produced by fungus that inhibit bacterial growth or kill the bacteria.

B) Penicillin- first antibiotic discovered by Alexander Flemming in 1929.