Chapter 19 Notes
Kingdoms Archaebacteria
andEubacteria
All bacteria are Prokaryotic.
This means that they are organisms that
are one-celled and do not contain a
nucleus or other membrane bound
organelles.
Their sizes range between 1-5
micrometers.
1 micrometer = 3.93700787 × 10-5 inches
All bacteria were once placed into the
Kingdom Monera, but now are now
divided into:
Kingdom Eubacteria
Kingdom Archaebacteria
• Cell walls contain a
carbohydrate called
peptidoglycan
• Cell membrane lipids
differ from
Archaebacteria
• DNA unlike eukaryote
• Cell walls do not contain a
carbohydrate called
peptidoglycan
• Cell membrane lipids
differ from Eubacteria
• DNA similar to eukaryote
DNA
Archaebacteria are ancient bacteria.
They were the first organisms to
appear on Earth.
The three major types of Archaebacteria
are:
Methanogens -(methane-producers)
responsible for the production of
methane, or Swamp gas, can be found:
Halophiles – are salt tolerant and live
in saturated brine and salted areas.
Thermophiles – are heat tolerant and live in hot
Springs and Black smokers (where hot gases
are released into the bottom of the ocean).
Kingdom Eubacteria contains more
evolved bacteria.
Some examples of Eubacteria are:
• Nitrogen Fixing Bacteria
• Cyanobacteria
• Bacteria involved in Decomposition
• Bacteria involved in Food Processing
And
Bacteria that cause disease.
Nitrogen Fixing-fixing bacteria convert nitrogen gas
into a form of nitrogen that can be used by plants. They
are essential to the ecosystem and its food webs.
Cyanobacteria
Cyanobacteria, originally called blue-green bacteria or
blue-green algae, produce 20 – 30% of the oxygen here
on Earth.
Pseudomonas is one kind of bacteria found in the soil. Bacteria
recycle dead plants and animals by turning them into minerals
and nutrients that plants can use. This is called decomposing.
http://www.earth-cards.com/pseudomonas_bacteria.htm
Shapes of
Bacteria
Bacteria are
classified
based on a
number of
characteristics.
One of these
characteristics
is their shape.
Coccus
(sphere)
Bacillus (rod)
Spirillum
(spiral)
• Meningitis
• Strep throat
• Anthrax
• Botulism
• Whooping Cough
• Syphilis
Gram Staining (another method for distinguishing
between types of bacteria)is determined by the
composition of the bacterial cell wall.
• Gram Positive
(peptidoglycan)
• Gram Negative (no
peptidoglycan)
Bacteria can also be grouped into
categories based on how they obtain
their nutrition.
Autotrophs can
produce their own
food given an
outside energy
source.
Chemoautotrophs use energy from chemical
reactions in their environment to produce their
own food.
Bacteria from a Black Smoker
Black Smoker
Photoautotrophs use sunlight as an energy
source to convert simple compounds into
complex compounds used for food.
Heterotrophs must obtain food from their
environment. They do this by either
Ingestion: an anemone
feeding
Absorption: a fungus
absorbing nutrients
Bacteria can also be sorted based on their method of converting
“food” into energy.
All living things require energy. They
must break down food to obtain it.
This is done in different manners
depending on the organism and the
presence of oxygen in the
environment.
Aerobic Cellular Respiration
requires oxygen (releases more
energy, ATP)
Bacteria can also be
Releasing
identified
based on
Energy
their methods of
Facultative Anaerobes switch
Anaerobic Cellular Respiration
between cellular
respiration energy.
releasing
(also called fermentation) does
and fermentation depending on
the presence of oxygen in their
environment
not require oxygen and releases
less energy.
Bacteria can reproduce asexually by
binary fission or sexually by
conjugation.
Rate of Bacterial Growth over Time
Phases of the Bacterial Growth Curve
• a. Lag phase - bacteria adjust to their
environment
• b. Exponential growth phase - bacterial
increase rapidly in number (binary fission)
• c. Stationary phase - bacteria reproduce at the
same rate as cells die
• d. Death phase - bacteria die as their
environment is contaminated and/or their
food is used up.
Spore Formation
• Under unfavorable conditions, spores
(vegetative reproductive structures) can form.
These structures are resistant to harsh
conditions, such as heat, cold, and drought
and can survive for years. Given good
conditions, they grow.
• Endospores are composed of a thick internal
wall that encloses DNA and some cytoplasm.