Kingdom Monera Kingdoms Eubacteria

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Kingdom Monera(Kingdoms Eubacteria
Archaebacteria)

• Prokaryotic organisms

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Bacteria were unknown throughout most of human
history. Anton van Leeuwenhoek is given credit
for being the first person to observe them in the
late 1600s.
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Bacteria are the cause of many human diseases and
death. Louis Pasteur made significant
contributions to the study of bacteria and
disease. He discovered that gentle heating will
kill many bacteria and that immunization could
greatly reduce the death rate from chicken pox
and anthrax. While bacteria are associated with
sickness, they are indispensable to life on earth
(decomposition, digestion, etc.). Bacteria are
of tremendous interest to scientists with genetic
engineering becoming more and more prevalent.
Bacteria are used to produce human insulin in
large amounts, as well as many other products.
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Both Eubacteria and Archaea are Prokaryotic

• The genetic material is not organized within a
  nucleus bounded by a nuclear membrane.
• The DNA is not part of the DNA-histone complex
  known as chromatin.
• Membrane-bound organelles such as mitochondria,
  chloroplasts, golgi apparatus, endoplasmic
  reticulum and lysosomes are not present.

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• Those prokaryotes that do have flagella have a
  different structure of flagella than is found in
  eukaryotic cells.
• Prokaryotes, with few exceptions, have no
  microtubules, or tubulin. No cholesterol is
  found in the cell membrane.
• Most prokaryotic cells have cell walls of unique
  composition. This structure contains highly
  polymerized amino sugars cross-linked by amino
  acids.

http//micro.magnet.fsu.edu/cells/bacteriacell.htm
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• Other characteristics of prokaryotes. . .
• Cell volume is about one-thousandth that of small
  eukaryotic cells
• Cell length is about one-tenth that of small
  eukaryotic cells
• Most are unicellular, but some form colonies or
  filaments
• Have ribosomes
• Genetic material is a circular DNA molecule
• Reproduction is simple and fast
• None have cilia, but spirochetes have internal
  filaments that permit the cell to move about and
  swim
• Archaebacteria and Eubacteria have been separated
  into two Kingdoms. Even though they are both
  prokaryotic, they are very different in
  composition.

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• Generalized information on Eubacteria. . .
• Bacteria are ubiquitous
• Many will form endospores when conditions are
  adverse some have been activated that had lain
  dormant for at least 10,000 years.
• Most are single-celled some exist as colonies or
  filaments
• The bacterial cell wall, composed mainly of
  peptidoglycan, supports the cell and protects
  it from chemical and osmotic damage.
• The cell wall structure provides a strong, rigid
  framework that supports the cell, maintains its
  shape, and keeps it from bursting (many bacteria
  live in hypotonic conditions)
• The cell wall provides little protection in
  hypertonic conditions (e.g. jams, jellies, salt
  fish)

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Some bacteria are heterotrophic. Those
heterotrophic bacteria that subsist on dead
organic material are called saprobes. Some
bacteria are autotrophic and can synthesize all
of the organic molecules that they need. Some
are photosynthetic and some are
chemosynthetic. Anaerobic bacteria prosper in the
absence of free oxygen. Obligate anaerobes are
actually harmed by oxygen. Aerobic bacteria
either can survive in the presence of oxygen or
actually need it for survival. Different kinds of
bacteria can survive and reproduce at
temperatures from 0 to 75 degrees C. One kind of
bacteria, the thermobacteria, thrive at a
temperature of 90 degrees C (almost boiling).
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Many bacteria can form spores, reproductive cells
that can grow into new individuals. The process
of making spores, called sporulation, involves
the production from free cytoplasmic precursors
of a spore that is sheathed in a tough
impermeable outer coat. The spore contains the
cells DNA and a bit of cytoplasm. These spore
are unbelievable tough! They can survive boiling
temperatures and other adverse conditions. A
spore will give rise to a new bacterial cell when
conditions become favorable again. There have
been cases of spores being reactivated that have
lain dormant for ten thousand years!
http//www1.indstate.edu/thcme/micro/sporform.html

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Many Bacteria are decomposers

• Bacteria are associated with causing illness, but
  they are extremely important in maintaining life
  on Earth. Bacteria are the principle organisms
  of decay - breaking down organic molecules to
  their simpler constituents, so they can be used
  by living things over and over again.

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Bacteria are the only organisms known to be able
to do nitrogen fixation which converts
atmospheric nitrogen (N2) to ammonia (NH3).
Other bacteria can oxidize ammonia to nitrates
(NO3), the form of nitrogen used by most green
plants. These processes are critical to
life. Most bacteria are heterotrophic saprobes.
Many bacteria develop symbiotic relationships
with other organisms commensals - heterotrophs
that live symbiotically with their host causing
neither harm nor benefit. Pathogens (parasites) -
heterotrophs that live at the expense of their
host and cause diseases.
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• Some bacteria are chemosynthetic
• Chlorophyll absorbs light in the near-infrared
  portion of the spectrum rather than in the
  visible light range.
• They do not produce oxygen because water is not
  used as the hydrogen donor sulfur bacteria
  produce free sulfur.
• CO2 H2S ? C6H1206 S2 (sulfur deposits)
• rather than CO2 H20 ? C6H12O6 O2 (free to
  atmosphere)

http//library.thinkquest.org/18828/data/fn_4.html

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Facultative Anaerobes - Use O2 when it is
available, but can metabolize anaerobically if
necessary. Obligate anaerobes - cannot tolerate
O2. Fermentation - anaerobic metabolism of
carbohydrates (yields ethanol, glycerol, and
lactic acid. Putrification - anaerobic metabolism
of protein and amino acids (yields nitrogen and
sulfur gases - really stinky)
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Reproduction - Bacteria can reproduce asexually
by transverse binary fission.
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• Steps of binary fission. . .
• Chromosome replication
• Plasmid replication
• Invagination of mesosome
• New cell wall
• This fission can occur very rapidly - some
  species can divide every 20 minutes under ideal
  conditions.

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Genetic recombination in bacteria can take place
by transformation, conjugation, or
transduction.Genetic material can be exchanged
between individuals.

• Transformation - fragments of DNA released by a
  broken cell are taken in by another bacterial
  cell.
• Conjugation - two cells of different mating types
  come together and genetic material is transferred
  from on to the other.
• Transduction - bacterial genes are carried from
  one bacterial cell into another within a
  bacteriophage.