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BACTERIA
BACTERIA
• Domain Bacteria,
Kingdom Eubacteria
(true)
• Domain Archea,
Kingdom
Archaebacteria
(ancient)
• Used to be combined
under Kingdom
Monera
* Prokaryotic
* Heterotrophic or
Autotrophic
Kingdom
Eubacteria
Kingdom
Archaebacteria
PROKARYOTES
Recall that the archaea are more closely related to
the eukaryotes, while the bacteria are related to cell
organelles such as mitochondria and chloroplasts.
Recall Prokaryotic Vs. Eukaryotic
• Prokaryotes DO NOT
have:
– Nucleus
– Membrane-bound
organelles
• Prokaryotes DO have:
– DNA (all)
– Ribosomes (all)
– Cell membrane (all)
– Cell Wall (many)
– Flagella (some)
– Capsule (many)
– Pili (some)
• Ex. bacteria
• Eukaryotes DO have:
– Nucleus
– Membrane-bound
organelles
(such as mitochondria,
ER, golgi, etc.)
– DNA (inside nucleus)
– Ribosomes
– Cell membrane
– Cell Wall (some)
– Flagella (a few)
• Ex. Animals, Plants, Fungi,
Protists
Eubacteria Diagram
Good web-site to look at eubacteria cell structure:
http://www.enchantedlearning.com/subjects/bacterium/
Pili on a bacillus
bacterium
CHARACTERISTICS of Bacteria:
1. Most reproduce asexually through binary
fission. ( Dividing in half; identical
offspring)
2. Some reproduce sexually by conjugation
connecting at their pili. (cell to cell contact;
new combination of genes)
3. Classified by cell shape, cell wall
(difference between Archaea and the
Bacteria, and between Gram + bacteria and
Gram - bacteria), respiration, and nutrition.
1. Asexual reproduction
Rod-shaped bacteria
dividing by binary fission
2. Sexual reproduction
Conjugation in Bacteria
3. Three different shapes:
1. Coccus (spheres):
2. Bacillus (rods):
3. Spirillum (spirals):
Two different arrangements:
Strepto (chains)
Staphylo (clusters)
Bacterial Shapes
bacillus
coccus
spirillum
3. Comparison Gram + & Gram Eubacteria
Feature
Gram +
Gram -
Color
Purple
Red
Amount of
More
Less
Toxicity
Less
More
Antibiotic
effective against?
Most of the
time
Not always
peptidoglycan
Peptidoglycan – the tan rods in the diagram; lots in Gram
+, little in Gram -
Gram +
Gram –
(the lipid layer
on the outside
makes it hard
for antibiotics
to work on G-
3. Nutrition Types
• AUTOTROPHS
– Photosynthetic—use pigments to capture light energy to
convert to chemical energy ex. cyanobacteria
– Chemosynthetic—use inorganic molecules or organic
molecules to make amino acidsproteins; live in soil and
nitrify ammonia ex. sulfur bacteria & methanogens;
nitrifying bacteria (Nitrobacter spp.)
• HETEROTROPHS
– Principal decomposers (along with fungi)
– Many produce antibiotics (ex. Streptomyces)
– Some fix nitrogen (ex. Rhizobium)
Cyanobacteria
Characteristics of Bacteria
continued
4. Some may form endospores.
5. Toxins – chemicals produced by
bacteria that are poisonous to
eukaryotic cells and cause
disease
4. ENDOSPORES
• Thick wall
• Resistant to heat, dryness, etc
• May survive for years in harsh
conditions
• When conditions are favorable, the
bacteria will grow from the spore
• Example: ANTRHAX
endospore
Archaebacteria: “ancient”
Autotrophic
Cell walls with NO peptidoglycan
found in harsh environments
1. Methanogens- no oxygen, make
methane gas
2. Thermophiles- very hot water
3. Halophiles- very salty conditions, 10x
saltier than ocean water
Archaea in San
Francisco Bay area
– extremely high
salinity.
What kind of
archaea are these?
EUBACTERIA “true”
• Largest and most diverse of the
bacterial kingdoms
• Found everywhere
• Most are HETEROTROPHIC
• Cell walls are present with
peptidoglycan
• Many have flagella that aid in
movement
Diseases caused by Bacteria:
* Tuberculosis
* Anthrax
* Lyme disease
* E. coli
* Bubonic plague
*Typhoid fever
*Cholera
*Strep throat
*Dental cavities
*diphtheria
*pneumonia
Yellow bacillus bacteria in the lining of the
human nose. This species causes pneumonia.
Beneficial Bacteria:
There are some bacteria you’ve just got to love!
* Bacteria is used to make certain foods
like cheese and yogurt.
* To manufacture plastics and many
pharmaceuticals.
* Digests cellulose in animals
* Sewage treatment plants
* Medicines like insulin
Mutualistic bacteria: the fish
provides the bioluminescent
bacteria under its eye with
organic materials, the fish
uses its living flashlight
to lure prey and to signal
potential mates.
Questions to Ponder
• Why are bacteria important organisms in the
ecosystem?
• What are the shapes and arrangements of
bacteria and how can these be used in
classification?
• Describe bacterial diseases including cause,
symptoms, and transmission.
• In what ways are bacterial beneficial to us?
Explain.
How do we know
that those little
bitty things under
the microscope
aren’t all the same
“stuff”?
How do we know
that the Archaea
are more closely
related to the
Eukarya?