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BACTERIA Structure, Function, Reproduction, and Growth
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CLASSIFYING PROKARYOTES There are two groups or kingdoms: Eubacteria Live almost everywhere Archaebacteria Live in harsh environments May be the ancestors of eukaryotes
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COMPARE THE KINGDOMS are classified into the kingdoms of live in harsh environments such as include a variety of lifestyles such as EubacteriaArchaebacteria Infecting large organisms Thick mudLiving in soil Animal digestive tracts Salty lakesHot springs Bacteria
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WHAT ARE BACTERIA? Single-celled organisms Prokaryotes No distinct nucleus No membrane-bound organelles Size = 1-5 micrometers Very small, very primitive cells About 10 times smaller than eukaryotic cells HOWEVER, they are much larger than viruses
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IDENTIFYING PROKARYOTES Prokaryotes are identified by: Their shape The ways they move The ways they obtain energy
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BACTERIA SHAPES Bacteria come in three basic shapes Coccus Round, spheres Bacillus Rods Spirillum Spiral or spring-like
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MOVEMENT Some are propelled by a flagellum Some glide slowly along a layer of slime-like material they secrete Some do not move at all
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OBTAINING ENERGY Autotrophs Photoautotrophs Carry out photosynthesis (cyanobacteria) Chemoautotrophs Obtain energy from inorganic molecules (ie. Ammonia, hydrogen sulfide, nitrites, sulfur, or iron Heterotrophs Take in organic molecules and then break them down Photoheterotrophs Combination between autotrophs and heterotrophs; they photosynthesize and need organic compounds for nutrition
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BACTERIA GROW IN GROUPS Diplo Pairs Strepto Chains Staphlo Clusters diplococcus diplobacillus streptobacillus streptococcus staphlobacillusstaphlococcus
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REPRODUCTION Binary fission Asexual Cell grows nearly double in size, replicates its DNA, and divides in half Produces 2 identical “daughter” cells View binary fission View binary fission
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WHAT BACTERIA NEED FOR GROWTH Moisture Food Warm temperature Most need oxygen (aerobic bacteria), however, some die in the presence of oxygen (anaerobic bacteria) Where are these growth requirements met? Incubators Inside bodies of birds and mammals
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WHAT STOPS BACTERIA GROWTH? Cold temperature Dryness (freeze-dried foods) No food No oxygen (for aerobes)
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BACTERIA Beneficial and Harmful Aspects
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BENEFICIAL ASPECTS Help digest food in intestine Help in food processing Break down waste in sewage Ferment sugars to make alcohol Can be used to make medicine Decompose dead organisms to return nutrients to soil or water Some help fertilize soil by forming nitrates and nitrites Nitrogen-fixing bacteria living on plant roots Convert nitrogen into ammonia (form that plants can use) Can be used to clean up oil spills Petroleum eating bacteria
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HARMFUL ASPECTS Spoils food At home In stores In transit In restaurants In the field Contaminate water Cholera & typhoid Contaminate food Salmonella & botulism Food needs to be pasteurized (heated up to a really high temperature) Damage leather Soil bacteria Cause disease Only 1 percent of bacteria cause disease
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COMMON DISEASES CAUSED BY BACTERIA Tooth decay Lyme disease Tetanus Tuberculosis Salmonella food poisoning Pneumonia Cholera Streptococcus mutans Borrelia burgdorferi Clostridium tetani Mycobacterium tuberculosis Salmonella enteritidis Streptococcus pneumoniae Vibrio cholerae Regular dental hygiene Protection from tick bites Current tetanus vaccination Vaccination Proper food-handling practices Maintaining good health Clean water supplies DiseasePathogenPrevention
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