CHAPTER 7 “BACTERIA” (P. 186)

1. CHAPTER 7“BACTERIA” (P. 186)

2. are unicellular. • are prokaryotic. - their DNA ‘floats around’ in the cytoplasm. • creates foods. - cheeses/yogurt. • some cause disease. ex. strep throat / anthrax • have cell walls. • live everywhere. • in cold, hot, air, soil, etc.

3. Eubacteria Phylum Bacteria Phylum Cyanobacteria - can make their own food. Archebacteria - oldest. - live in extreme conditions. (page 191) Two Kingdoms of Bacteria Bacteria was discovered by van Leeuwenhoek in 1684.

4. There are three shapes of bacteria (p. 187) • cocci - round bacilli -rod shaped spirilla - spiral shaped

5. Some live by themselves, in chains, or in groups called colonies. Bacteria can reproduce asexually by quickly splitting into two cells. - called fission. (20 minutes)

6. They can also reproduce sexually • called conjugation. - an exchange of genetic materials.

7. Bacteria colonies

8. Bacteria Structure No nucleus. Flagella for movement.

9. Draw and label the structures of bacteria • the outermost layer is the capsule. - for protection. • some create an endospore (or wall). - it protects against high temperatures.

10. Bacteria decays our food. To prevent decay: • Dehydration - water is removed from food. -bacteria need water to survive. 2) High temperatures - cook / boil / bake - kills bacteria

11. 3) Cold temperatures - freeze / refrigeration. - stops or slows bacteria growth. • 4) Canning • boiling • - then air-tight covering

12. 5) irradiation - exposing food to radiation to kill bacteria. Pasteurization - heating to 1500 then quick cooled to 450. - stored at low temps. Ex. milk / apple juice

13. 7) Seal it - bacteria cannot get in.

14. Bacteria are very “tough”. Can live in: - hot springs 3500 F - ice - ocean depths - in your intestines - without oxygen - anaerobic

15. ASSIGNMENT:BOOK QUESTIONSPAGE 191: 1 / 2 / 4PAGE 199: 3 / 4

16. Some Bacteria can cause disease: ex. pneumonia / anthrax Pathogen - any organism which causes disease. Some bacteria destroy cells by releasing a toxin. ex. botulism ‘flesh-eating’ bacteria

18. Antibiotics (against life) • used to kill or slow the growth of bacteria. Ex. penicillin amoxocillin What is antibiotic resistance?

19. Cyanobacteria(p. 190) • second phylum of Eubacteria. • have chlorophyll but not chloroplasts. • also called “blue-green algae”. • many live in long chains. • not all are blue-green: there are red, yellow, and black.

20. There are different pigments which give cyanobacteria their color. They are a source of food for other organisms.

21. They are the cause of the ‘green slime’ on the surface of ponds.

22. Cyanobacteria are called nitrogen-fixers. • they grow among the roots of certain plants. Ex. soybeans, alfalfa • take nitrogen out of the air and create nodules in the soil. • adds nutrients. • saves $$ on fertilizer. Soybean ‘nodules’

23. A lot of nutrients in the water causes rapid growth called a ‘bloom’. • the cyanobacteria die and sink to the bottom. • other bacteria decompose them. • it takes oxygen out of the water. • the fish die…

24. ASSIGNMENT:WORKSHEET“BACTERIA”

25. HELPFUL BACTERIA • Keeps the environment free of dead material. - decays plants and animals. -breaks down our sewage and garbage. -returns nutrients to the soil.

26. Saprophyte - any organism which uses dead material for food. 2) Found in our intestines. - helps break down our food.

27. Nitrogen fixers - put nutrients back into the soil.

28. Economically important. • cheese, butter, and yogurt are made from milk ‘soured’ by bacteria. • different bacteria make a different type of cheese.

29. Harmful Bacteria • Can cause fatal diseases. ex. Pneumonia, anthrax.

30. 2) Can spoil food - could lead to starvation.

31. ASSIGNMENT:WORKSHEET‘BACTERIA IN YOUR LIFE’

32. VIRUSES( p. 52 - 55 ) • are not cells - there is not a nucleus, cytoplasm, etc. • spread disease. • very small - microscopic. • many different shapes. (p. 52)

33. Viruses are not considered to be alive. - are not in any kingdom. - cannot respond to stimuli. - can reproduce only inside a living cell.

34. A VIRUS IS MADE UP OF TWO PARTS: • Protein coat - the outside. - for protection • Nucleic Acid - genetic material. cccc

35. HOW DO THEY CAUSE DISEASE? • Attach -the virus attaches itself to a host cell of an organism. 2) Invade - the virus injects its nucleic acid into the host cell

36. 3) Copy - the virus’ nucleic acid “takes-over” the host cell. - it forces the cell to make copies of the virus instead of new cells. 4) Release - the cell finally bursts. Hundreds of new viruses are released to ‘attack’ new cells.

37. Chicken pox, AIDS, the common cold, measles, and small pox are all caused by viruses. - spread by water, touch, air, and insects.

38. ASSIGNMENT:WORKSHEET “VIRUS ATTACK”

39. Latent viruses • may “hide” in the host cell for years before “taking over”. ex. cold sore AIDS Active viruses enter and take over a cell immediately.

40. VACCINES • made of a weakened or damaged virus that cannot cause the disease. • cannot cure viral diseases - it prevents them from happening.

41. First created by Edward Jenner in 1796 to fight smallpox. He noticed the milkmaids did not have the scars from smallpox. All had clear skin but did have cowpox before. He used the ‘sores’ from cowpox

42. - the body reacts and destroys the ‘weak’ virus. -the body produces an antigen which “remembers” the virus and will destroy it when enters the body again.

43. Vaccinations have almost eradicated many diseases. Example: Polio - attacks the nervous system. President Franklin Roosevelt (FDR)

44. Example II: Smallpox - thought to be eradicated in 1981.

45. The body does have natural defenses against viruses. Interferon - a chemical which slows down the reproduction of viruses. - now used in cancer treatments.

46. Vaccines can prevent epidemics. • the rapid spread of a disease through an area. Ex. influenza (1917 - 1919) -killed 10 million world wide.

47. “Black Death” or Bubonic Plague. - 1300’s in Europe.

48. Viruses can change or mutate. • there are thousands of types of the common cold. • Scientists are now worried about “bird flu” • mutating into a human disease.

49. ASSIGNMENT:WORKSHEET“VIRUSES”

50. Viruses may someday help: Ex. Gene therapy - a gene is ‘defective’ and has sickle-cell anemia - a virus’ nucleic acid will be replaced with ‘healthy’ DNA. - the virus attacks and replaces the ‘bad’ DNA May help people with genetic diseases.