Bacteria
What are Bacteria? Leeuwenhoek- Dutch merchant- discovered bacteria. Bacteria are everywhere Foods, surface of things you touch, soil, ocean depths. Extreme environments, hydrothermal vents, others cold or acidic environments. One-celled organisms without membrane-bound organelles
Bacteria are unlike plant and animal cells because they are smaller. Prokaryotic- do not contain a membrane-bound nucleus or organelles. 3 Basic Shapes 1) spheres 2) rods 3) spirals Cocci- sphere shaped Spirilla- spiral shaped Bacilli- rod- shaped
Flagella- whiplike tails that move bacteria Fission- bacterial method of Reproduction It produces 2 new cells. How does bacteria obtain food and energy? aerobes- bacteria that live in places with a supply of oxygen. USE oxygen for respiration Anaerobes- organism that is adapted to live WITHOUT oxygen.
2 Kingdoms of Bacteria 1) Eubacteria 2) Archaebacteria Eubacteria – larger of the 2 Ex. Cyanobacteria Cyanobacteria make their own food using CO2, water, and sunlight. (Like Plants)
Archaebacteria The conditions in which these bacteria live are similar to those conditions found on Earth during early history. Live in salty environments (Dead Sea) Acidic or hot environments Hot springs Muddy swamps, intestines of cattle NOT in freshwater ponds. http://glencoe.mcgraw-hill.com/sites/dl/free/0078617022/164155/00044676.html
Bacteria in Your Life Without bacteria, you would not be healthy for long. Some bacteria produce antibiotics Help limit the growth of other bacteria. Antibiotics- produced by one organism, but inhibits or kills other organisms. Drug used to kill bacteria Saprophyte Organism that uses dead material as a food and energy source. Obtain food by feeding on dead or decaying organisms.
Nitrogen- fixing bacteria Change nitrogen from the air into forms that can be used by plants and animals. Why are nitrogen-fixing bacteria so important to plants? Plants cannot take nitrogen gas out of the atmosphere. They need it in forms of a nitrogen compound. The bacteria transform the nitrogen from the atmosphere into a usable form. It is estimated that nitrogen-fixing Bacteria save farmers several million Dollars in fertilizer costs each Year!
Have you had any bacteria for lunch lately? Yogurt, cheese, sauerkraut, pickles, olives, soy sauce. Bacteria break down substances in milk to make dairy products. But, it DOES NOT help make milk! Helpful bacteria can help clean up soils, digest dead organisms, and make medicines.
Harmful Bacteria Pathogen Toxins Endospores An organism that produces disease Ex. Strep throat Toxins Poisons produced by pathogens Ex. Botulism- a type of food poisoning that can result in death. Can grow inside sealed cans of food. Endospores Thick-walled structures around bacteria Harmful bacteria in food can be killed by heat. Why are botulism bacteria sometimes able to produce toxins when they have been heated? They protected themselves with endospores, and the heat was not of a high enough temperature or a long enough time to destroy the endospore.
Treating Bacterial Diseases Vaccine Solution made from dead or damaged bacteria that is used to prevent bacterial disease. Sterilization A process of food industry that is used to kill harmful bacteria.
Beneficial Bacteria What is one way bacteria are helping provide an alternative source for fuel for some cities? Methane gas is produced by certain bacteria as they break down plant and animal material from farm wastes and sewage. This can be used as fuel and some cities collect it!