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Bacteria powerpoint

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Bacteria powerpoint

  1. 1. Bacteria
  2. 2. Bacteria Facts <ul><li>Bacteria are found nearly EVERYWHERE on Earth!!!! </li></ul><ul><li>Have been found at the bottom of ocean trenches </li></ul><ul><li>Are on every surface </li></ul><ul><li>Have changed into hundreds of thousands of species </li></ul><ul><li>Numbers are estimated to be over 5 billion trillion trillion organisms </li></ul><ul><li>The earliest forms are believed to be around 3.5 billion years old </li></ul><ul><li>They are “prokaryotes” meaning they have no membrane-bound nuclei </li></ul>
  3. 3. Bacterial Classification <ul><li>Bacteria are classified mainly by: </li></ul><ul><li>*structure </li></ul><ul><li>*physiology (how they work) </li></ul><ul><li>*molecular compostion </li></ul><ul><li>*reaction to certain types of stains </li></ul><ul><li>Bacteria can be broken down into to two main groups: Archaebacteria and Eubacteria </li></ul>
  4. 4. Kingdom Archaebacteria <ul><li>Quite different than other bacteria </li></ul><ul><li>They have unusual lipids (fats) in their cell membranes </li></ul><ul><li>They have no peptidoglycan (a carbohydrate found in cell walls) </li></ul><ul><li>They are sometimes called “extremophiles” </li></ul><ul><li>Live in extreme environments </li></ul>
  5. 5. Thermoacidophiles <ul><li>Live in extremely acidic environments such as hot springs (up to 230 F) </li></ul><ul><li>Live near volcanic vents </li></ul><ul><li>Thrive in areas where the pH is less than 2 </li></ul><ul><li>Live in areas that leak scalding acid water at the bottom of the ocean </li></ul>
  6. 6. Halophiles <ul><li>Salt-loving bacteria </li></ul><ul><li>Found in areas with high salt concentrations </li></ul><ul><li>Great Salt Lake, Dead Sea, etc </li></ul><ul><li>Use salt to generate ATP </li></ul>
  7. 7. Methanogens <ul><li>Convert hydrogen and carbon dioxide to methane gas </li></ul><ul><li>Can only live in anaerobic conditions </li></ul><ul><li>Found in “swamp mud” </li></ul><ul><li>Found in the gut of animals </li></ul><ul><li>Produce “gas” we excrete </li></ul>
  8. 8. Kingdom Eubacteria <ul><li>“ Stereotypical” bacteria </li></ul><ul><li>Can be classified by shape and by staining </li></ul><ul><li>By shape: </li></ul><ul><li>Bacillus (plural: Bacilli) = rod-shaped </li></ul><ul><li>Coccus (plural: Cocci) = sphere-shaped </li></ul><ul><li>Spirillum (plural: Spirilla) = spiral-shaped </li></ul><ul><li>“ Streptococci” = cocci occur in chains </li></ul><ul><li>“ Staphylococci” = cocci occur in clusters </li></ul>
  9. 9. Common Bacteria & Problems <ul><li>“ Staph” infections….often found on skin. Acne, skin lesions/sores, etc </li></ul><ul><li>“ Strep” infections….strep throat, scarlet fever, impetigo, etc. </li></ul><ul><li>Food Poisoning - Escherichia coli infections </li></ul>
  10. 10. Gram Stain Procedure <ul><li>Gram positive: Retains Gram stain and appear purple. </li></ul><ul><li>Gram negative: Doesn’t retain Gram stain and appears pink </li></ul><ul><li>Gram positive bacteria have a thicker peptidoglycan layer so they can hold the purple stain </li></ul>
  11. 11. Phylum Cyanobacteria <ul><li>Are photosynthetic </li></ul><ul><li>Once considered “blue-green algae” </li></ul><ul><li>Eutrophication = population increase due to high availability of nutrients. </li></ul>
  12. 12. Phylum Spirochetes <ul><li>Spiral shaped </li></ul><ul><li>Heterotrophs </li></ul><ul><li>Live freely, symbiotically, or parasitically. </li></ul><ul><li>Examples include Lyme disease and the STD syphilis. </li></ul>
  13. 13. Phylum Gram-Positive Bacteria <ul><li>Not all species are Gram positive, a few are Gram negative </li></ul><ul><li>Includes: </li></ul><ul><li>species that cause strep throat </li></ul><ul><li>species that cause gum disease </li></ul><ul><li>Species include some dairy-producing bacteria </li></ul>
  14. 14. Phylum Proteobacteria <ul><li>Very large & diverse group </li></ul><ul><li>Includes: </li></ul><ul><li>Enteric bacteria (live in animal guts) </li></ul><ul><li>Chemoautotrophs (extract energy from minerals to make own food) </li></ul><ul><li>Nitrogen-fixing bacteria in soil </li></ul>
  15. 15. Some Phyla of Bacteria and Their Properties Gram negative Aerobic Anaerobic Photosynthetic autotrophic Flagella Some non-motile Bacilli Cocci spiral Proteobacteria Gram positive Aerobic Anaerobic Heterotrophic photosynthetic Flagella Some non-motile Bacilli Cocci Gram Positive Bacteria Gram negative Aerobic Anaerobic heterotrophic Corkscrew Spirals Spirochetes Gram negative Aerobic Photosynthetic autotrophic Gliding Some non-motile Bacilli Cocci Cyanobacteria Gram Rxn Metabolism Motility Shape Phylum
  16. 16. Bacterial Anatomy <ul><li>Cell wall - gives shape, protection </li></ul><ul><li>Cell membrane - regulates movement of materials in/out of the cell </li></ul><ul><li>Cytoplasm - contains DNA and other materials </li></ul><ul><li>Chromosomes - genetic material </li></ul><ul><li>Plasmid - contains genes obtained through genetic recombination </li></ul><ul><li>Capsule & slime layer - protection </li></ul><ul><li>Pilus - attachment to other surfaces </li></ul><ul><li>Endospore - protection against harsh environmental conditions </li></ul><ul><li>Flagellum - moves the cell </li></ul>
  17. 17. Bacterial Reproduction <ul><li>Sexual reproduction called “conjugation” </li></ul><ul><li>Involves two bacteria and a “sex pilus” </li></ul><ul><li>Results in genetically unique bacteria </li></ul><ul><li>Asexual reproduction called “binary fission” </li></ul><ul><li>Results in genetically similar/identical bacteria </li></ul><ul><li>Can occur very, very quickly </li></ul>

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