KINGDOMS OF ORGANISMS Kingdoms Archaebacteria and Eubacteria a

KINGDOMS OF ORGANISMS Kingdoms Archaebacteria and Eubacteria (a. k. a. Monerans)

Characteristics of the Kingdoms Archaebacteria and Eubacteria No membrane-bound nucleus n No membrane-bound organelles n Cell membrane n Unicellular n Smaller than almost all organisms n Prokaryotic n

Structures in a Typical Bacteria n n n n 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 n Bacterial cells can form endospores when living conditions become unfavorable n

Reproduction n Binary Fission: ¨ Cell division in which the cell forms 2 identical cells ¨ It is a form of asexual reproduction

Reproduction (cont. ) n 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 n Picking up and incorporating DNA from dead bacterial cells

Classification of Bacteria n Cell Shape: ¨ Spheres—cocci ¨ Rods—bacilli ¨ Spirals--spirilla n Respiration: ¨ Aerobes—use oxygen ¨ Anaerobes—do not use oxygen

Classification of Bacteria (cont. ) n Cell Wall Composition: ¨ Gram positive ¨ Gram negative n Nutrition: ¨ Autotrophs ¨ Heterotrophs—most heterotrophic bacteria are

Roles of Bacteria in the Biosphere Decomposers: break down organic materials n Bioremediation: bacteria are used to rid the environment of harmful substances (i. e. oil spills) n Manufacturing: bacteria are used to ferment sugar to make cheese, yogurt and some beverages n

Roles of Bacteria in the Biosphere (cont. ) n n n 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 n Some pathogens use the body’s cells as food; ex: mycobacterium tuberculosis n Other pathogens release toxins that can travel throughout the body; ex: streptococcus n

Vaccines An injection of dead bacteria or virus will stimulate the immune system to make antibodies n The antibodies will provide immunity against the disease n

Antibiotics can work to block bacterial cell growth and reproduction n Some antibiotics, like penicillin, attack the cell wall of the bacterial cells n Penicillin makes holes in the wall causing water to rush into the cell and rupturing it n

Bacteria Wanted Poster Research Project n http: //www. accessexcellence. org/AE/ATG/ data/released/0210 -Joyce. Calo/

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