Download Structure of Bacteria

Bacteria
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Earliest
Prokaryotes
• Most numerous
organisms on
Earth
• Include all
bacteria
• Earliest fossils
date 2.5 billion
years old
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Classification
of Life
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Three Domains of
Life
• Archaea –
prokaryotes living in
extreme habitats
• BacteriaCyanobacteria and
eubacteria
• Eukarya –
Protozoans, fungi,
plants, & animals
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Archaebacteria
• Archaebacteria can live in
extremely harsh
environments
• They do not require oxygen
and can live in extremely
salty environments as well as
extremely hot environments
• Called the Ancient bacteria
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Archaebacteria
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Kingdoms of Bacteria
Eubacteria:
 Called the true
bacteria
 Most bacteria are in
this group
 Include photosynthetic
Cyanobacteria
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Characteristics
3 basic shapes
• Bacillus: rod-shaped
• Coccus: sphere-shaped
• Spirrilla: spiral-shaped
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Bacterial
Shapes
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Grouping of Bacteria
• Diplo- Groups of
two
• Strepto- chains
• Staphylo- Grapelike
clusters
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Diplococcus
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Streptococcus Causes
Strep Throat
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Streptobacilli
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Staphylococcus
Bacterial
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Staphylococcus
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Bacillus - E. coli
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Spirillum
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Characteristics
of Bacteria
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Bacterial Structure
• Microscopic prokaryotes
• No nucleus or membranebound organelles
• Contain ribosomes
• Single, circular
chromosome in nucleoid
region
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Bacterial
Structure
PLASMIDS
• Have small rings of
DNA called Plasmids
• Unicellular
• Small in size (0.5 to
2μm)
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Flagella
• Bacteria that
are motile have
appendages
called flagella
• Attached by
Basal Body
• A bacteria can
have one or
many flagella
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Pili
• Short protein appendages
• Smaller than flagella
• Adhere bacteria to
surfaces
• Used in conjugation for
Exchange of genetic
information
• Aid Flotation by
increasing buoyancy
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Bacterial Cell
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Protection
• Cell Wall made of
Peptidoglycan
• May have a sticky
coating called the
Capsule for
attachment to host or
other bacteria
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Useful Bacteria
• Some
bacteria
can
degrade oil
• Used to
clean up oil
spills
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Benefits of Bacteria
•
•
•
•
Nitrogen Fixation
Photosynthesis
Decomposers
Food production- cheese &
yogurt
• Sewage Treatment- sludge to
methane gas
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Nutrition, and
Reproduction
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Modes of Nutrition
• Saprobes – feed on dead
organic matter
• Parasites – feed on a host
cell
• Photoautotroph – use
sunlight to make food
• Chemoautotroph – oxidize
inorganic matter such as
iron or sulfur to make food
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Reproduction
• Bacteria reproduce
asexually by binary fission
• Single chromosome
replicates & then cell
divides
• Rapid
• All new cells identical
(clones)
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Cellular organism copies it’s genetic information
then splits into two identical daughter cells
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Binary Fission E. coli
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Reproduction
• Bacteria reproduce
sexually by Conjugation
• Form a tube between 2
bacteria to exchange
genetic material
• Held together by pili
• New cells NOT identical
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Conjugation
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Pili in Conjugation
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Bacterial Respiration
• Anaerobes
carry on
fermentation
• Aerobes
carry on
cellular
respiration
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Spore Formation
• Form endospore
whenever when
habitat conditions
become harsh
(little food)
• Able to survive for
long periods of
time as endosperm
• Difficult to
destroy (heat
resistant)
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Pathological bacteria (diseasecausing)
• Bubonic plague- wiped out part of
Europe during the middle ages, fever,
buboes (bubo-swollen gland) formed
from bleeding lymph nodes.
• Cholera and typhoid fever- severe
diarrhea, vomiting, often fatal, from
contaminated water.
• Dental caries (cavities)- dental caries,
holes form in teeth.
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Disease causing bacteria
• Diptheria- sore throat, fever, chills,
thick gray coating on back of tongue.
• Dysentery- severe diarrhea, often
bloody, can be fatal.
• Gangrene- affected area begins to
necrofy (die) and rot.
• Gonorrhea- STD, inflammation of
urinary and reproductive tracts, often
leads to sterility in women.
• Lyme disease- carried by deer ticks,
rash, pain, and swelling in joints.
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Disease causing bacteria
• Salmonella- causes severe food
poisoning.
• Syphilis- STD, 1st stage includes canker
sores, 2nd phase includes rash, 3rd stage
includes insanity, fatal.
• Tetanus- “lock jaw,” found in soil and
rust.
• Tuberculosis- known as TB, white
death, consumption, infects lungs,
coughing up blood, often fatal.
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