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calendargrumpyΒιοτεχνολογία

14 Δεκ 2012 (πριν από 4 χρόνια και 6 μήνες)

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Prokaryotes

Chapter 27

Slide
2

of 20

Kingdom
Monera



Prokaryotes


Unicellular (Single
-
celled)
organisms that lack
membrane
-
bound
organelles and nuclei


Divided by

1. Domain

2. Nutritional Classification

3. Reactivity with Oxygen


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of 20

Domain Classification

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Nutritional Classification

AUTOTROPHS

1.
Photoautotrophs


Photosynthetic autotrophs


Like plants


Light energy


Energy (ATP)


Carbon dioxide


organic compounds (Glucose)


2.
Chemoautotrophs


Inorganic substances


Energy (ATP)


Carbon dioxide


organic compounds (Glucose

Slide
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of 20

Nutritional Class (Page 2)

HETEROTROPHS

3.
Photoheterotrophs


Light energy


Energy (ATP)


Get carbon from consuming other organisms


3.
Chemoheterotrophs


Get both carbon & energy from consuming other
organisms

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of 20

Reactivity with Oxygen


Whether they must react with O
2
, must be in absence
of O
2
, or they can be in absence or not of O
2


Obligate aerobe


Require O
2

for respiration


Obligate anaerobe


O
2

is a poison to them


Facultative anaerobe


Prefer to use O
2
, but don’t need
to use it to live


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of 20

Questions


Which of the 3 classifications is appropriate for
humans?


What would you call something that uses light for
energy, but must obtain carbon in an organic form?


Aerobes would do what form of catabolism?


What about anaerobes?


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of 20

Roles of Prokaryotes


Decomposers



recycle dead organic manner


Pathogens



organisms that cause disease


Nitrogen Fixation


Atmospheric N
2



NH
4


ONLY way to fix nitrogen into organic systems


Play a vital role in
genetic engineering


E. Coli is used to manufacture human insulin

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of 20

Bacteria’s Roles (Page 2)


Symbionts

in the gut


Manufacture vitamins


Digest cellulose


Digest Food


Bioremediation



remove pollutants


Used in production of
cheese & yogurt

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of 20

Symbiotic Roles


Symbiotic


relationships with other species


Mutualism



Both
symbionts

benefit


Pollinators & Flowering plants



Commensalism



One organism benefits other is
unharmed


Fern growing in the shade of a tree



Parasitism



One benefits at the expense of another


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of 20

Antibiotics


Chemicals that kill prokaryotes


Usually produced by fungi


NOT effective against viruses


Many plasmids confer resistance to different antibiotics


MDR
-
TB



Multi
-
Drug Resistant (resistant to multiple
antibiotics) Tuberculosis bacteria


XDR
-
TB



eXtremely
-
Drug Resistant (resistant to almost
every antibiotic) Tuberculosis bacteria


Slide
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of 20

Archaebacteria


Unicellular


Prokaryotes


No Peptidoglycan
in their cell walls


Able to live in extreme environments


Resemble the first cells on Earth


Extreme
Halophiles



Salt lovers


Extreme
Thermophiles



exist in extreme temperatures (high
temperatures)


Methanogens



Use CO2 to oxidize H2


Produce methane as a by product


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of 20

Examples of Archaebacteria

Thermoacidophiles

Hot Springs
-

Thermophiles

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Eubacteria


Broadly categorized as Gram
-
negative or Gram
-
positive


Due to whether the bacterium is able to take up Gram’s
stain


Gram
-
positive


large amount of peptidoglycan in cell
wall


Susceptible to antibiotics


Gram
-
negative


structurally more complex cell wall


Contains less peptidoglycan


Outer membrane contains
lipopolysaccharides


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of 20

Slide
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of 20

5 Important Bacterial Subgroups


Proteobacteria


Chlamydias


Spirochetes


Gram
-
Positive Bacteria


Cyanobacteria

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of 20

Proteobacteria


Includes photoautotrophs,
chemoautotrophs
,
and
heterotrohps


Some are aerobic, others are anaerobic


Nitrosomonas



Nitrogen fixing bacteria


Examples:


Escherichia coli (E coli)


benign & pathogenic


Vibrio

Cholerae



Cholera


Rhizobium



live in roots of legumes

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of 20

Chlamydias
,
Spirochets


Gram
-
negative like
proteobacteria


Chlamydias


ALL are parasitic


Lack peptidoglycan


Chlamydia = most common STD or VD


Spirochetes


Helical shape


Move by rotating internal flagella
-
like
filaments


Syphilis and Lyme disease


Others are free
-
living (not parasitic or
pathogenic)

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of 20

Gram
-
positive Bacteria


Diversity rivals
proteobacteria


Streptomyces



source of many
antibiotics


Bacillus
anthracis


Clostridium
botulinum


Mycoplasms



bacteria that lack
cell walls (WTF?)


Synthetic organism?

Slide
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of 20

Cyanobacteria


ONLY photoautotrophs


Plant
-
like photosynthesis


May have
heterocytes



can fix
nitrogen