Download KINGDOMS OF ORGANISMS

KINGDOMS OF
ORGANISMS
Kingdoms Archaebacteria and
Eubacteria (a.k.a. Monerans)
Characteristics of the Kingdoms
Archaebacteria and Eubacteria
No membrane-bound nucleus
 No membrane-bound organelles
 Cell membrane
 Unicellular
 Smaller than almost all organisms
 Prokaryotic
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Structures in a Typical Bacteria
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Flagella—long hairlike structures growing from a
cell that aid in movement
Chromosome—usually a single, circular piece
of DNA
Ribosome—used for making proteins
Plasmid—small circular piece of DNA
Cell membrane (a.k.a. plasma membrane)—
separates the cell from its external environment
Pili—short, hairlike structures involved in
reproduction and cell-to-cell contact
Cell wall—protects and support the cell
Capsule—located around the cell wall; bacteria
with capsules are more likely to cause diseases
Endospores
Thick walled structures that can resist
heat, drought, and radiation
 Bacterial cells can form endospores when
living conditions become unfavorable
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Reproduction
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Binary Fission:
 Cell
division in which the cell forms
2 identical cells
 It is a form of asexual reproduction
Reproduction (cont.)
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Conjugation:
 Process
of exchanging genetic material
though cell-to-cell contact
 DNA and plasmids move through the pili from
one bacterial cell to another
Transformation
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Picking up and incorporating DNA from
dead bacterial cells
Classification of Bacteria
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Cell Shape:
 Spheres—cocci
 Rods—bacilli
 Spirals--spirilla
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Respiration:
 Aerobes—use
oxygen
 Anaerobes—do not use oxygen
Classification of Bacteria (cont.)
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Cell Wall Composition:
 Gram
positive
 Gram negative
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Nutrition:
 Autotrophs
 Heterotrophs—most
heterotrophic
bacteria are
Roles of Bacteria in the Biosphere
Decomposers: break down organic
materials
 Bioremediation: bacteria are used to rid
the environment of harmful substances
(i.e. oil spills)
 Manufacturing: bacteria are used to
ferment sugar to make cheese, yogurt and
some beverages
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Roles of Bacteria in the Biosphere
(cont.)
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Medicine: bacteria are used to make human
proteins such as insulin
Nitrogen fixation: provides usable nitrogen for
plants; ex: bacteria that live on roots of legumes
Symbiosis: relationship between 2 organisms in
which at least one of the partners benefits; ex:
bacteria found in the intestines of mammals help
with digestion and provide vitamins
Pathogens
Bacteria that cause diseases are called
pathogens
 Some pathogens use the body’s cells as
food; ex: mycobacterium tuberculosis
 Other pathogens release toxins that can
travel throughout the body; ex:
streptococcus
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Vaccines
An injection of dead bacteria or virus will
stimulate the immune system to make
antibodies
 The antibodies will provide immunity
against the disease
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Antibiotics
Antibiotics can work to block bacterial cell
growth and reproduction
 Some antibiotics, like penicillin, attack the
cell wall of the bacterial cells
 Penicillin makes holes in the wall causing
water to rush into the cell and rupturing it
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Bacteria Wanted Poster
Research Project
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http://www.accessexcellence.org/AE/ATG/
data/released/0210-JoyceCalo/
WANTED
Helicobacter pylori
Description: spiral-shaped, Gram-negative bacteria
M.O.: attacks the mucus layer of the stomach and
duodenum
Victims: attacks humans and destroys the mucus
layer causing ulcers and can lead to cancer; can infect
individuals who remain symptom free so number of
victims is unknown
Hideout: found in epithelium below the mucus layer of
the stomach and duodenum
Weapons: combination therapy—antibiotics and acid
reducers