2 Prokaryote amp Eukaryote Evolution 3 Cellular Evolution Current evidence indicates that eukaryotes evolved from prokaryotes between 1 and 15 billion years ago Two theories 1 Infolding theory ID: 658778
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Slide1
1
Bacteria
Structure and FunctionSlide2
2
Prokaryote & Eukaryote
EvolutionSlide3
3
Cellular Evolution
Current evidence indicates that
eukaryotes evolved from prokaryotes
between 1 and 1.5 billion years ago
Two theories:
1.
Infolding theory
2.
Endosymbiotic theorySlide4
4
Infolding Theory
The
infolding of the prokaryotic plasma
membrane gave rise to eukaryotic organelles.
infolding
organelleSlide5
5
Endosymbiotic Theory
Endosymbiosis refers to
one species living within another
(the host)
Movement of
smaller photosynthetic
&
heterotrophic
prokaryotes
into larger prokaryotic host cells
Formed cell organelles
chloroplast
mitochondriaSlide6
6
Prokaryotic & Eukaryotic CellsSlide7
7
Earliest Prokaryotes
Most numerous
organisms on Earth
Include all
bacteria
Earliest fossils date
2.5 billion years oldSlide8
8
Classification of LifeSlide9
9
Three Domains of Life
Archaea
–
prokaryotes living in extreme habitats
Bacteria
-
Cyanobacteria and eubacteria
Eukarya
–
Protozoans, fungi, plants, & animalsSlide10
10
Kingdoms of Bacteria
Archaebacteria:
Found in
harsh environments
Undersea
volcanic vents
, acidic
hot springs
,
salty
waterSlide11
11
ArchaebacteriaSlide12
12
Kingdoms of Bacteria
Eubacteria:
Called the
true bacteria
Most bacteria
are in this group
Include photosynthetic
CyanobacteriaSlide13
13
EubacteriaSlide14
14
Characteristics of BacteriaSlide15
15
Bacterial Structure
Microscopic
prokaryotes
No
nucleus or membrane-bound organelles
Contain
ribosomes
Single, circular
chromosome in
nucleoid
regionSlide16
16
Bacterial CellSlide17
17
Protection
Cell Wall made of
Peptidoglycan
May have a sticky coating called the
Capsule
for attachment to host or other bacteriaSlide18
18
Sticky Bacterial CapsuleSlide19
19
Bacterial Structure
Have small rings of DNA called
Plasmids
Unicellular
Small
in size (0.5 to 2μm)
PLASMIDSSlide20
20Slide21
21
Bacterial Structure
Infoldings
of cell membrane carry on
photosynthesis & cellular respiration
Infoldings called
MesosomesSlide22
22
Mesosomes
MESOSOMESlide23
23
Bacterial Structure
Most grow best at
pH of 6.5 to 7.0
Many act as decomposers
recycling nutrients
Some cause
diseaseSlide24
24
Staphylococcus BacterialSlide25
25
Useful Bacteria
Some bacteria can
degrade oil
Used to clean up
oil spillsSlide26
26
Useful Bacteria
Other uses for bacteria include making yogurt, cheese, and buttermilk.Slide27
27
Flagella
Bacteria that are
motile
have appendages called
flagella
Attached by
Basal Body
A bacteria can have
one or many
flagellaSlide28
28Slide29
29
Flagella
Made of
Flagellin
Used for
Classification
Monotrichous:
1 flagella
Lophotrichous:
tuft at one end
Amphitrichous:
tuft at both ends
Peritrichous: all around bacteriaSlide30
30
Monotrichous
Lophotrichous
Amphitrichous
PeritrichousSlide31
31
Question:
What is this type of bacteria ?Slide32
32
Pili
Short protein
appendages
Smaller
than flagella
Adhere
bacteria to surfaces
Used in
conjugation
for Exchange of genetic information
Aid
Flotation by increasing buoyancySlide33
33
Pili in ConjugationSlide34
34
Bacterial ShapesSlide35
35
Shapes Are Used to Classify
Bacillus:
Rod shaped
Coccus:
Spherical (round)
Vibrio:
Comma shaped with flagella
Spirillum:
Spiral shape
Spirochete:
wormlike spiral shapeSlide36
36Slide37
37
Grouping of Bacteria
Diplo
- Groups of two
Strepto
- chains
Staphylo
- Grapelike clustersSlide38
38Slide39
39Slide40
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DiplococcusSlide41
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Streptococcus Causes Strep ThroatSlide42
42
StaphylococcusSlide43
43
Bacillus -
E. coliSlide44
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StreptobacilliSlide45
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SpirillumSlide46
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SpirochetesSlide47
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LeptospiraSlide48
48Slide49
49
Bacterial KingdomsSlide50
50
Archaebacteria
Lack peptidoglycan
in cell walls
Have
different lipids
in their cell membrane
Different types of
ribosomes
Very
different gene
sequencesSlide51
51
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 bacteriaSlide52
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Archaebacteria
Subdivided into 3 groups:
Methanogens
Thermoacidophiles
Extreme HalophilesSlide53
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Methanogens
Live in
anaerobic environments (no oxygen)
Get energy by
changing H
2
& CO
2
into methane gas
Found in
swamps
, sewage treatment plants, digestive tracts of animalsSlide54
54
Methanogens
Break down
cellulose in a cow’s
stomach
Produce
marsh (methane) gasSlide55
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Extreme Halophiles
Live in very
salty water
Use
salt to generate ATP
(energy)
Dead Sea, Great Salt Lake
inhabitantsSlide56
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Thermoacidophiles or Thermophiles
Live in
extremely hot environments
Found in
volcanic
vents, hot springs,
cracks on ocean floor that leak acidSlide57
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Kingdom Eubacteria
True BacteriaSlide58
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Characteristics
3 basic shapes
(coccus, bacillus, spirilla)
Most are
heterotrophic
(can’t make their own food)
May be
aerobic or anaerobic
Identified by
Gram stainingSlide59
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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 reddish pinkSlide60
60
Gram Positive
Have
thick layer of peptidoglycan
(protein-sugar complex)
Single lipid layer
Stain
purple
Can be treated with
antibioticsSlide61
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Gram Positive Bacteria
Lactobacilli
(makes yogurt & buttermilk)
Actinomycetes (
make antibiotics)
Clostridium
(lockjaw bacteria)
Streptococcus
(strep throat)
Staphylococcus (
staph infections)Slide62
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Gram Negative Bacteria
Thin layer of peptidoglycan
in cell wall
Extra
thick layer of lipids
Stain
pink or reddish
Hard to treat
with antibiotics
Some
photosynthetic
but make sulfur not oxygenSome fix nitrogen for plantsSlide63
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Gram Negative
Rhizobacteria
grow in root
nodules of legumes
(soybeans, peanuts)
Fix N
2
from air into usable ammoniaSlide64
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Gram Negative
Rickettsiae
are parasitic bacteria carried by ticks
Cause
Lyme disease & Rocky Mountain Spotted FeverSlide65
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Cyanobacteria
Gram
negative
Photosynthetic
Called
blue-green bacteria
Contain
phycocyanin
(red-blue) pigments &
chlorophyllSlide66
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Cyanobacteria
May be red, yellow, brown, black, or blue-green
May grow in
chains
(
Oscillatoria
)
Have
Heterocysts
to help fix N
2
First to re-enter devastated areasSome cause Eutrophication (use up O2 when die & decompose in water)Slide67
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CyanobacteriaSlide68
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Spirochetes
Gram
positive
Flagella at each end
Move in
corkscrew
motion
Some
aerobic
; others
anaerobic
May be free living, parasitic, or symbiotic Slide69
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Enteric Bacteria
Gram
negative
Can live in
aerobic & anaerobic
habitats
Includes
E. coli
in intestines
Salmonella
–
causes food poisoningSlide70
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Chemoautotrophs
Gram
negative
Obtain energy from
minerals like iron
Found in
freshwater pondsSlide71
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Nutrition, Respiration, and ReproductionSlide72
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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 foodSlide73
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Methods of Respiration
Obligate Aerobes
– require O
2
(tuberculosis bacteria)
Obligate Anaerobes
– die if O
2
is present (tetanus)
Facultative Anaerobes
– don’t need O
2, but aren’t killed by it (E. coli)Slide74
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Bacterial Respiration
Anaerobes
carry on fermentation
Aerobes
carry on cellular respirationSlide75
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Reproduction
Bacteria reproduce
asexually by binary fission
Single chromosome replicates
& then cell divides
Rapid
All new cells
identical (clones)Slide76
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Cellular organism copies it’s genetic information then splits into two identical daughter cellsSlide77
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Binary Fission
E. coliSlide78
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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 identicalSlide79
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ConjugationSlide80
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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)Slide81
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Transduction & Transformation
Genetically change
bacteria
May become
antibiotic resistant
Transformed bacteria
pick up pieces of DNA from dead bacterial cells
Transduction
– viruses carry foreign DNA to bacteria;
used to make insulinSlide82
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Pathenogenic BacteriaSlide83
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Pathogens
Called
germs or microbes
Cause
disease
May produce
poisons or toxins
Endotoxins
released after bacteria die (
E. coli
)
Exotoxins released by Gram + bacteria (C. tetani)Slide84
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