1. Life Science Unit 2, Chapter 1

2. Virus • A virus is a tiny particle that contains nucleic acid encased in protein

3. Virus

4. Virus is much smaller than a cell, 25-250 nanometers (one-billionth of a meter) • About 300 x smaller than a cell

5. Alive or not? • Scientists disagree about whether viruses are living things or not. • They can reproduce (but only by infecting a living cell) • They can mutate • They have RNA, DNA, and nucleic acids

6. Viruses are not made of cells Cannot reproduce/mutate outside of host Can survive dormant outside of cells for years Viruses resemble their host cells

7. THE FLU! • http://www.youtube.com/watch?v=Rpj0emEGShQ

8. Virus Reproduction • Viruses want to reproduce! • Because the virus is so much like their host cells, they can survive only in those hosts • Each virus works only in certain cells and infects only certain species on bacteria, plants, or animals

9. Viral Infection • Viral infection: penetration of a virus or its nucleic acid into a host cell

10. Read • Take a couple minutes and read page 89-90

11. Get started on your notes from yesterday • Try to finish in about 20 minutes;-)

12. Summarize • Make sure you include: • 1: the process by which a virus infects bacteria (what its called and the process) • 2: How viruses infect animal and plant cells • 3: Retroviruses and an example • 4: The “basic pattern of virus infection”

13. Bellwork • What is the most interesting thing you discovered about your virus?

14. Bacteria • Bacteria are one celled, • Have a protective outer wall • Have a jelly-like cytoplasm with enzymes

16. Bacteria move by flagellum (whip like tail) • Wiggling, air,wind, orgnamism, etc.

17. Many different types of bacteria • Round=cocci • Rod-shaped=bacillli • Spiral=spirella

20. Some bacteria live alone, others lie together • Diplo=pair • Staphylo=cluster • Strepto=chain

22. Someone Read page 101, paragraphs 1-2

23. Bacteria reproduce asexually • One parent • Identical offspring • Some reproduce through splitting • Others through budding

24. Aerobic-bacteria that need oxygen • Anaerobic-bacteria that do not )in fact many die in its presence)

25. If life conditions are not suitable for bacteria, some may form endospores • Protective capsules that allow bacteria to live for decades in a dormant state until conditions are favorable

26. Autotrophs • Many bacteria are autotrophs-make their food through photosynthesis • Some use hydrogen during photosynthesis and make sulfur instead of oxygen • Bad smell from rotting food….

27. Heterotrophs • Heterotrophs must eat from other organisms-which causes infections • These are the ones that make us sick

28. Decomposers • Get energy from breaking down dead organisms.

29. articles • http://news.nationalgeographic.com/news/2008/11/081105-bacteria-mining_2.html • http://www.dvice.com/archives/2011/12/rock_eating_bac.php • http://www.livestrong.com/article/29090-good-uses-bacteria/ • http://medcitynews.com/2013/11/biotech-uses-listeria-cancer-therapy/ • http://www.wisegeek.com/what-are-the-different-medical-uses-of-beneficial-bacteria.htm

30. Bacteria is both vital for, and harmful to all life on this planet • Give an example of each

31. Methanogens • Bacteria that make methane • Anaerobic bacteria • Live in sewage, sediment, intestines, etc. • Helps animals digest food • Methane produced is essential to our atmosphere • Too much is harmful, though

32. Relationships • Symbiosis-one organism lives on/near/inside another organism and at least one benefits

33. Symbiosis

34. Bacteria and Humans Read the article and do the following: 1.summarize your article in no less than 2 paragraphs 2. What did you learn about the other uses of bacteria?

35. Helpful and harmful bacteria • Bacteria in food can make us sick • Nitrogen-fixing bacteria helps to fertilize crops • Bacteria is involved in much of the food we eat • Vinegar, cheese, buttermilk, sour cream, soy sauce, pickles, yogurt

36. Good bacteria • http://www.youtube.com/watch?v=6FPy5m1-BQI

37. Antibiotics are drugs used to kill harmful bacteria and other microorganisms • They kill by interfering with bacterial cell functions

38. Someone read “overusing a good thing” on 110.

39. Bacteria and Disease • Pathogens: disease causing bacteria/microorganisms • They can cause diseases in humans, animals, and plants

40. Some of the diseases caused by bacteria include strep throat, cholera, and leprosy, pneumonia, tuberculosis, typhoid fever

41. Bacteria enter the body through natural openings (eyes, nose, mouth) or through breaks in the skin • They destroy healthy cells, preventing the body from functioning properly

42. http://www.youtube.com/watch?v=s-HThHRV4uo

43. Other bacteria produce poisons called toxins • Sometimes toxins are released after bacteria die • Other bacteria cause food poisoning, infections, and blood poisoning

44. Some bacteria may live in a healthy person’s body and be harmless until that person’s resistance is low • When resistance is low your body can’tfightbacteria as quickly as theyreproduce. • Thatswhyyougetsickeasierwhenyou are tired or stresses

45. Antibiotics are the primary method for killing bacteria

46. Food and Bacteria • Most foods are spoiled by bacteria • When bacteria break down food they can make it taste bad or even poison it!

47. Protecting Our Food • Canning: food is heated to kill bacteria and sealed in airtight containers • Preservatives: Chemicals added to foods slow the growth of bacteria and mold

48. Protecting Our Food • Freeze-Drying: most bacteria need moisture and oxygen to grow. • Freeze-drying removes all the moisture and then it is sealed in an airtight container • Pasteurization: the process of heating a liquid to kill harmful bacteria

49. Refrigerators and freezers also slow down the growth of bacteria.

50. Activity • Read the “Focus on Alexander Fleming” • Then, write a journal entry as if you were Alex. • Tell about your discovery, how you found it, what brought you to science, and how your discovery will change science! • Minimum 4 paragraphs, 5 sentences each;-)