Download Structure of Bacteria

Bacteria
Chapter 18.1
1
Three Domains of
Life
•
Bacteria-
Cyanobacteria and
eubacteria
• Archaea – prokaryotes
living in extreme
habitats
• Eukarya – Protozoans,
fungi, plants, & animals
2
Characteristics
of Bacteria
3
Domain Bacteria
Kingdom Eubacteria
Found just about
everywhere
Strong cell walls
w/
peptidoglycan
Some have a
secondary cell
wall
Eubacteria
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Domain Archaea
Kingdom Archaebacteria
• Live in extreme
and hostile
environments
• Has ribosomal
proteins similar
to eukaryotic
cells
• Cell walls lack
peptidoglycans
Archaebacteria
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Methanogens
• Break down
cellulose in a
cow’s
stomach
• Produce
marsh
(methane)
gas
8
Extreme Halophiles
• Live in very
salty water
• Use salt to
generate
ATP (energy)
• Dead Sea,
Great Salt
Lake
inhabitants
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Thermoacidophiles or
Thermophiles
• Live in
extremely hot
environments
• Found in
volcanic vents,
hot springs,
cracks on ocean
floor that leak
acid
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Clicker Question!
Have a membrane bound
nucleus and organelles:
A: Prokaryotes
B: Eukaryotes
C: Nokaryotes
Eubacteria vs Archaebacteria
Prokaryotic &
Eukaryotic Cells
13
Earliest
Prokaryotes
• Most numerous
organisms on
Earth
• Include all
bacteria
• Earliest fossils
date 2.5 billion
years old
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What domain can be found
in harsh environments
like: Undersea volcanic
vents, acidic hot
springs, salty water?
A: Bacteria
B: Archaea
C: Eukarea
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Clicker Question!
Some eubacteria gain energy
from the sun (cyanobacteria),
but the rest have to gain
energy by consuming other
organisms. These are called:
A. Homotrophs
B. Heteroeaters
C. Heterotrophs
D. Homoconsumers
Bacterial Structure
• Microscopic
• Do not have a nucleus or
membrane-bound
PLASMIDS
organelles
• Have ribosomes
• Single, circular
chromosome
• Have plasmids
• Unicellular
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Bacterial Cell
18
Sticky Bacterial Capsule
Prevents drying out, allows it to
attach to other surfaces, prevents
it from being engulfed, & shelters
it from antibiotics
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Pili in Conjugation
Hairlike structures that help them
attach to surfaces and allow for
transfer of genetic material
between two bacteria
20
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Flagella
• Bacteria that
are motile have
appendages
called flagella
• A bacteria can
have one or
many flagella
22
Monotrichous
Lophotrichous
Amphitrichous
Peritrichous
23
Clicker Question!
What structure does this
bacterium use for motility?
A: Flagella
B: Cilia
C: Pili
24
Bacterial
Shapes
25
Shapes Used to
Classify
• Bacillus:
• Coccus:
• Spirillum:
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Grouping of Bacteria
• Diplo• Strepto• Staphylo-
28
29
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Clicker Question!
What shape and grouping describes the
bacteria pointed out below?
A: Staphalacoccus
B: Streptobacillus
C: Diplococcus
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Staphylococcus
Bacterial
32
Streptococcus Causes
Strep Throat
33
Bacillus - E. coli
34
Streptobacilli
35
Spirillum
36
Leptospira
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Clicker Question!
1. _________
2. _________
3. _________
4. _________
5. _________
A. Staphylococcus
B. Coccus
C. Spirillum
D. Bacillus
E. Streptococcus
F. Diplococcus
6. _________
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Gram Staining
• Developed in 1884 by
Hans Gram
• Bacteria treated with
purple Crystal Violet & red
Safranin stains
• Cell walls either stain
purple or pink
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Gram Positive
• Have a thick
layer of
peptidoglycan
• Stain purple
• Can be treated
with antibiotics
40
Gram Negative
Bacteria
• Thin layer of peptidoglycan in
cell wall
• Outer layer of lipids
• Stain pink
• Hard to treat with antibiotics
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Gram Negative
• Rickettsiae are
bacteria
carried by ticks
• Cause Lyme
disease & Rocky
Mountain
Spotted Fever
42
Clicker Question!
Which type of bacteria is
susceptible to antibiotics?
A: Gram Positive (Dark Purple)
B: Gram Negative (Light Pink)
2 kinds of reproduction:
• Binary fission
• Conjugation
Cellular organism copies it’s genetic information
then splits into two identical daughter cells
45
Binary Fission E. coli
46
Clicker Question!
What kind of reproduction is depicted
in the photo below?
A: Asexual
B: Conjugation
C: Binary fission
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Bacterial Respiration
• Anaerobes
• Aerobes
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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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Bacteria and Survival
Bacterial Survival:
Mutations
• Reproduce quickly
• Low rate to fix
mistakes in DNA
• Leads to increase in
genetic diversity
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Bacterial Survival:
Endospores
Ecology of Bacteria
All living things need Nitrogen
Bacteria fix
nitrogen to make
it usable!
Bacteria decompose
and recycle
nutrients!
Normal Flora
•Harmless
•Live on, in, and around
you
•E. coli helps make
Vitamin K used to help
clot blood
Useful Bacteria
• Some
bacteria
can
degrade oil
• Used to
clean up oil
spills
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Bacteria make food
• Yogurt
• Cheese
• Buttermilk
• Pickles
• Chocolate
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Bacteria make Medicine
• Vitamins
• Antibiotics:
–Streptomycin
–Bacitracin
–Tetracycline
–Vancomycin
Pathogens
STD: Syphilis, gonorrhea, Chlamydia
Respiratory: Strep throat, pneumonia,
whooping cough, tuberculosis, anthrax
Skin: Acne, boils
Digestive: Gastroenteritis, food poisoning,
cholera
Nervous: Botulism, tetanus, bacterial
meningitis
Other: Lyme disease, typhoid fever
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