Transcript Bacteria File

Bacteria are Prokaryotes
Kingdom Bacteria
Bacteria are ubiquitous – located everywhere! air, water,
land, and living organisms including people.
General Characteristics:
1. All are unicellular (one-celled structural level)
2. All are prokaryotic - cells that lack nucleus
(no nuclear envelope) (PRO = NO nucleus)
3. All have cell walls – NO cellulose in cell walls
4. Can live in both aerobic (with O2) and
anaerobic (without O2) environments
Relative Size
Ex: Streptococcus
Ex: Lactobacillus
Ex: Spirillium
What shape?
bacillus
spirillum
coccus
coccus
bacillus
spirillum
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) Decomposersdecay dead
organisms and
recycle nutrients
B) Pathogenscause 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
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 toxinspoisons
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.