BACTERIA
Biology Chapter 18.2
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Bacteria are very small
2
This is a
pore in
human skin
and the
yellow
spheres are
bacteria
3
Bacteria
are very
small
compared to
cells
with
nuclei
4
Bacteria
Bacteria
compared
to a white
blood
cell that
is going
to eat it
5
Clean skin has about 20 million
bacteria per square inch
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Evolution/Classification





Most numerous on Earth
Most Ancient
Microscopic Prokaryotes
Evolution has yielded many species
adapted to survive where no other
organisms can.
Grouped based on:



Structure, physiology, molec. Composition
reaction to specific types of stain.
Eubacteria= Germs/bacteria
Archaebacteria
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Kingdom Archaebacteria


First discovered in extreme environments
Methanogens: Harvest energy by
converting H2 and CO2 into methane gas



Anaerobic, live in intestinal tracts
Extreme halophiles: Salt loving, live in
Great Salt Lake, and Dead sea.
Thermoacidophiles: Live in acid
environments and high temps.

Hot Springs, volcanic vents
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Volcanic
vents on the
sea floor
9
Chemosynthetic bacteria use the
sulfur in the “smoke” for energy
to make ATP.
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The red color of this snow is due to a blue-green bacteria
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Kingdom Eubacteria

Can have one of three basic shapes
1. Bacilli – rod-shaped
2. Spirilla – spiral-shaped
3. Cocci – sphere-shaped
Staphylococci – grape-like
clusters
Streptococci – in chains
SHOW ME
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BACTERIA PICS
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Bacillus
bacteria
are rod
or
sausage
shaped
14
Coccus
bacteria
are
sphere
or
ball
shaped
15
Spirillium bacteria have a corkscrew shape
16
Diplo-bacteria
occur in pairs,
such as the
diplococcus
bacteria that
causes
gonorrhea
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Staphylo bacteria occur
in clumps, such
as this
staphylococcus
bacteria that
causes common
infections of
cuts
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Streptobacteria occur
in chains of
bacteria, such
as this
streptococcus
bacteria that
causes some
types of sore
throats
19
Spirillium bacteria
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Diplobacillus
bacteria
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Streptococcus
bacteria
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Staphylococcus bacteria
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The tip of a
needle
The red and
yellow dots
are bacteria
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Gram Stain

Gram-positive retain stain and appear purple


Have thicker layer in cell wall.
Gram-negative do not retain stain and take
second pink stain instead.
Phylum
Shape
Motility
Metabolism
Gram
reacion
Cyanobacteria
Bacilli,
Cocci
Gliding,
some nonmotile
Aerobic,
Gramphotosynthetic negative
autotrophic
Spirochetes
Spirals
Corkscrew
Aerobic, and
anaerobic;
heterotrophic
Gram-Pos
Bacilli,
cocci
Flagella;
some nonmotile
Aer/anaer.;
Mostly
heterotrophic, gramphotosynthetic positive
Proteobacteria
Bacilli,
cocci,
spiral
Flagella;
some nonmotile
Aer/anaer.;
heterotrophic,
photosynthetic
autotrophic
Gramnegative
Gramnegative
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STRUCTURE OF BACTERIA
Structure
Function
Cell Wall
Protects and gives shape
Outer
Membrane
Protects against antibodies (Gram Neg. Only)
Cell
Membrane
Regulates movement of materials, contains
enzymes important to cellular respiration
Cytoplasm
Contains DNA, ribosomes, essential compounds
Chromosome
Carries genetic information
Plasmid
Contains some genes obtained through recomb.
Capsule &
Protects the cell and assist in attaching cell to
Slime Layer other surfaces
Endospore
Protects cell agains harsh enviornments
Pilus
Assists the cell in attaching to other surfaces
Flagellum
Moves the cell
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No Nucleus-DNA in Cytoplasm
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Nutrition and Growth




Heterotrophic or Autotrophic
Some are Photoautotrophs – Use sunlight for Energy
Some are Chemoautotrophs.
Many are Obligate Anaerobes.
 Oxygen = Death
 Ex.

Some are Faculatative Anaerobes
 With or without Oxygen
 Ex.


Clostridium tetani – Tetanus
Escherichia Coli
Some are Obligate Aerobes
 Ex.) Mycobacterium tuberculosis
Temperature requirements

Some are Thermophilic, Some prefer acidic envmt.
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These
heterotrophic
bacteria
digest oil -remember oil
is partially
decayed plant
and animal
cells
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REPRODUCTION
IN
BACTERIA
(please add to notes)
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No Nucleus-DNA in Cytoplasm
31
BACTERIA REPRODUCES
BY FISSION
First the chromosomal DNA
makes a copy
The DNA replicates
32
NEXT THE CYTOPLASM
AND CELL DIVIDES
The two resulting cells are
exactly the same
33
In addition to
the large
chromosomal
DNA, bacteria
have many
small loops of
DNA called
Plasmids
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Genetic Recombination

Nonreproductive Methods bacteria can acquire new
genetic material.
Characteristic
Transformation Conjugation
Transduction
Method of DNA Across cell wall
Transfer
and cell
membrane of
recepient
Through a
By a virus
conjugation
bridge between
two cells
Plasmid
transfer
Yes
Yes
Not likely
Chromosome
transfer
No
Sometimes
No
Antibiotic
resistance
acquired
Yes
Yes
Sometimes
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TRANSFORMATION
This plasmid of
DNA is new to
the bacteria –
added by
transformation!
Produces the
glowing protein
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CONJUGATION
37
TRANSDUCTION
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Bacteria and Disease
Disease
Pathogen
Areas
affected
Mode of
transmission
Botulism
Clostridium botulinum
Nerves
Improperly
preserved food
Cholera
Vibrio cholerae
Intestine
Contaminated water
Dental Caries
Streptococcus mutans,
sanguis, salivarius
Teeth
Environment to
mouth
Gonorrhea
Neisseria gonorrhoeae
Urethra,
fallopian
Sexual contact
Lyme disease
Berrelia burgdorferi
Skin, joints
Tick bite
Rocky
Mountain SF
Rickettsia recketsii
Blood, skin
Tick bite
Salmonella
Salmonella
Intestine
Contaminated food,
water
Strep throat
Streptococcus pyogenes
URT, blood,
skin
Sneezes, coughs,
etc.
Tetanus
Costridium tetani
Nerves
Contaminated
wounds
Tuberculosis
Mycobacterium tuberculosis
Lung,
bones
coughs
39
Some
bacteria
cause
diseases -Disease
causing
bacteria
are call
PATHOGENIC
40
Helicobacter
pylori
is the
pathogenic
bacteria
that can
causes ulcers
41
Leprosy is a
bacterial
infection
that
decreases
blood flow to
the
extremities
resulting in
the
deterioration
of toes, ears,
the nose and
the fingers.
42
BOTULISM
43
CHOLERA
44
DENTAL CARIES
45
ROCKY MOUNTAIN SF
46
LYME DISEASE
47
SALMONELLA
48
STREP THROAT
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TETANUS
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TUBERCULOSIS
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Common Antibiotics
Antibiotic
Mechanism
Target bacteria
Penicillin
Inhibits cell wall synthesis
Gram Positive
Ampicillin
Inhibits cell wall synthesis
Broad spectrum
Bacitracin
Inhibits cell wall synthesis
Gram Positive – Skin
Ointment
Cephalosporin
Inhibits cell wall synthesis
Gram Positive
Tetracycline
Inhibits Protein Synthesis
Broad spectrum
Streptomycin
Inhibits Protein Synthesis
Gram Neg. tuberculosis
Sulfa drug
Inhibits cell metabolism
Bacterial meningitis,
UTI
Rifampin
Inhibits RNA synthesis
Gram Pos., some Neg.
Quinolines
Inhibits DNA Synthesis
UTI
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Some Final Information


Because antibiotics have been overused,
many diseases that were once easy to
treat are becoming more difficult to
treat.
Some Bacteria are Useful



Ex.) Producing and Processing food
Breaking down dead organic material
Make unripened cheese like ricotta and
cottage by breaking down the protein in
milk.
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