kingdoms of organisms kingdoms archaebacteria and eubacteria (a.k.a. monerans)
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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
Structures in a Typical Bacteria 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
Reproduction
Binary Fission:Cell division in which the cell forms
2 identical cells It is a form of asexual reproduction
Reproduction (cont.)
Conjugation:Process of exchanging genetic material
though cell-to-cell contactDNA and plasmids move through the pili from
one bacterial cell to another
Transformation
Picking up and incorporating DNA from dead bacterial cells
Classification of Bacteria
Cell Shape:Spheres—cocciRods—bacilliSpirals--spirilla
Respiration:Aerobes—use oxygenAnaerobes—do not use oxygen
Classification of Bacteria (cont.)
Cell Wall Composition:Gram positiveGram negative
Nutrition:AutotrophsHeterotrophs—most bacteria are
heterotrophic
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
Roles of Bacteria in the Biosphere (cont.) 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
Vaccines
An injection of dead bacteria or virus will stimulate the immune system to make antibodies
The antibodies will provide immunity against the disease
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
Bacteria Wanted Poster Research Project
http://www.accessexcellence.org/AE/ATG/data/released/0210-JoyceCalo/
W A N T E D
Helicobacter pyloriDescription: spiral-shaped, Gram-negative bacteriaM.O.: attacks the mucus layer of the stomach and duodenumVictims: 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 unknownHideout: found in epithelium below the mucus layer of the stomach and duodenumWeapons: combination therapy—antibiotics and acid reducers