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Bacteria

Bacteria. Remember they are everywhere! In your food (yogurt), air (germs) on your body (remember our video?). Anton van Leeuwenhoek found them by accident. Remember him?.

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Bacteria

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  1. Bacteria Remember they are everywhere! In your food (yogurt), air (germs) on your body (remember our video?)

  2. Anton van Leeuwenhoek found them by accident. Remember him? • Bacteria are prokaryotes. The genetic material in their cells is not contained in a nucleus. They do not have a nucleus. • Bacteria also lack many other structures that are found in eukaryotic cells.

  3. What does a bacteria have? • DNA-tangled string • Cell wall-rigid and protective • Cell membrane-controls what goes in and out. • Cytoplasm-jelly-like material • Ribosomes-makes proteins • Flagellum-helps with movement—if there is not a flagellum then the bacteria cannot move on their own—air, water, or objects move them.

  4. Bacterial shapes • Three basic shapes: • Spherical--------------------- • Rod-like---------- • Spiral---------------------------

  5. Sizes of bacteria • Vary greatly • The biggest is about the size of a period at the end of a 12-font size. • Average is much smaller. Strep bacteria is 0.5-1 micrometer in diameter. A micrometer is one millionth of a meter! Thiomargaritanamibiensis

  6. Obtaining Food and Energy • Bacteria must have a source of food and a way of breaking down the food to release its energy= Respiration • Some are autotrophs and make their own food. • Some use chemicals from the environment. Like those that live in hot springs in Yellowstone Park. • Some are hetertrophs and must consume other organisms or food—from milk and meat or decaying leaves on a forest floor.

  7. Respiration • Remember that respiration is a process of breaking down food to release its energy. • Some bacteria do not breath oxygen so they would die in the presence of oxygen.

  8. What is Bacteria’s Role in Nature? • Bacteria are not all bad—they are involved in oxygen and food production, environmental recycling and cleanup, and also in health maintenance and medicine production.

  9. Oxygen • Bacteria that are autotrophs produce oxygen as a waste product and put it back into the atmosphere—like a plant does.

  10. Food Production uses of bacteria • Cheese • Sauerkraut • Pickles • Apple cider vinegar • Buttermilk • Yogurt • Sour cream

  11. What is pasteurization ? • Louis Pasteur was the inventor. • Food or beverages are heated to a temperature that is high enough to kill most harmful bacteria w/o changing the taste of the food.

  12. Environmental Recycling • The use of decomposers to break down the dead organisms into small chemicals are “nature’s recyclers. • They live in the soil. • Some bacteria prefer oil and cleanup oil spills.

  13. Health and Medicine • Bacteria live in your intestines and help you digest your food. Some make vitamins for you. • Others take up space so harmful bacteria cannot attach to your intestines and make you sick. • Some are used to produce insulin for diabetics.

  14. By the way—how does a vaccine work? • By having the vaccine introduced into your body---it stimulates your body to produce chemicals that destroy specific viruses or bacteria. • Vaccines are made from dead or altered viruses or bacteria so they cannot cause the disease but activate your body’s natural immune defenses. • They put your body onalertso it will “destroy” if the germ enters your body.

  15. What about antibiotics? • These are chemicals that can kill bacteria without harming you or your cells!!  • They are naturally made by some bacteria and fungi. Penicillin weakens the cell walls of some bacteria and the cell burst!!

  16. OK—so what is antibiotic resistance? • This results when some bacteria are able to survive in the presence of an antibiotic and they become “super bugs”! • Tuberculosis caused a problem • In 1940’s cases dropped but then • some resistant bacteria lived • and the cases increased over • the following 20 years.

  17. Do you think this antibiotic resistance is a problem today? • Yes!! • How does it occur—you know strong bacteria survive but also------- • If you stop taking antibiotics before the dose is complete=stronger bacteria also survive, can mutate and become stronger so—take the complete course of your medicine!!

  18. What is the final word about bacteria? • Some are good • Some are bad • Turn to page 49A. Draw and label the bacteria cell. Color it as well. Use about ½ a page. • Write this down and now to • Our last slide. . . . . .

  19. When you are done with the bacteria cell drawing, label and coloring-- go to--------- • Page 43A and draw the virus particle there. Draw, label and color also using about ½ a page so you can see it well.

  20. OK---get to work!!

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