1. Pathogens – Bacteria & Viruses Protists & Fungi Too

2. A Pathogen is…  Pathogen = Any disease causing agent. –Examples:  Bacteria: Streptococcus, Staphylococcus  Virus: HIV, Influenza (Swine Flu), The common cold  Protist: Plasmodium (malaria)  Fungi: Ringworm, Athletes Foot

3. Viruses – Properties of Life Properties of Life Cellular organization ReproductionYes Metabolism Homeostasis AdaptionYes ResponsivenessYes Growth and Development NO

4. Virus Size

5. Viruses are SOOO Small!  Too small to see with a regular light microscope  Must use an electron microscope to be seen.

6. Parts of a Virus  Capsid= “head”…protein that encloses viral genome  Genome= double stranded DNA OR single stranded DNA or RNA

8. Viral Body Plans  Genetic material is DNA or RNA  Coat is protein Complex virus (bacteriophage) Polyhedral virus Rod-shaped virus head sheath tail fiber

9. Viruses are Obligate Intracellular Parasites  Obligate like an obligation – can only replicate inside other cells  Must live within a specific host cell – example: cats don’t get chicken pox  Use the host cell for replication, metabolism, etc.

10. Viruses cause disease  Influenza –Infects the upper respiratory tract  Can also cause cancer –Hepatitis B  liver cancer –Epstein-Barr virus  Burkitt’s lymphoma –Human Papilloma Virus  cervical cancer

11. HIV, the AIDS virus  Glycoproteins on HIV envelope recognize surface proteins of human white blood cells  RNA virus  Includes the reverse transcriptase enzyme

12. Defenses against viruses  Skin and mucus membranes  Inflammation (redness, swelling, warmth and pain)  White blood cells  Antibodies- specific proteins that target a specific virus  Interferons- enzymes that prevent the virus from replicating

13. T4 Bacteriophages on Escherichia coli) bacteria. T4 bacteriophages are parasites of E. coli, a bacteria common in the human gut. The virus attaches itself to the host bacteria cell wall by its tail fibers. The sheath then contracts, injecting the contents of the head (DNA) into the host. The viral DNA makes the bacteria manufacture more copies of the virus. TEM X40,000. Credit: © Dr. George Chapman/Visuals Unlimited

14. T4 Bacteriophages on Escherichia coli bacteria. T4 bacteriophages are parasites of E. coli, a bacteria common in the human gut. The virus attaches itself to the host bacteria cell wall by its tail fibers. The sheath then contracts, injecting the contents of the head (DNA) into the host. The viral DNA makes the bacteria manufacture more copies of the virus. TEM X60,000. Credit: © Dr. George Chapman/Visuals Unlimited

15. Bacteria - Prokaryotes  Eubacteria = True Bacteria. –Cell wall contains the carbohydrate peptidoglycan  Archaeabacteria = Ancient Bacteria. –NO peptidoglycan in cell walls. –MORE similar to Eukaryotes!!! (US) –Live in harsh environments

16. Bacteria are very small

17. This is a pore in human skin and the yellow spheres are bacteria

18. Bacteria are very small compar- ed to cells with nuclei

19. Bacteria compared to a white blood cell that is going to eat it Bacteria

20. Clean skin has about 20 million bacteria per square inch

21. Structure  No nucleus  No membrane bound organelles  DNA is circular Plasmids

22. Bacteria Shapes Page 546

23. E. coli is a gram-negative, facultatively anaerobic, rod prokaryote undergoing conjugation. One strain has fimbriae. E. coli can cause urinary tract infections, traveler's diarrhea, nosocomial infections, and a variety of skin and wound infections such as scalded skin syndrome, scarlet fever, erysipelas and impetigo. TEM. Credit: © Dr. Dennis Kunkel/Visuals Unlimited 28 45 64 Bacterial Reproduction

24.  Bacterial reproduction Cellular organism copies it’s genetic information then splits into two identical daughter cells

25. Conjugation http://images.google.com/imgres?imgurl=http://content.answers.com/main/content/wp/ en/thumb/0/02/350px- BacterConjugation.png&imgrefurl=http://www.answers.com/topic/bacterial- conjugation&h=410&w=350&sz=75&hl=en&start=1&tbnid=JeAQL49IMC- LqM:&tbnh=125&tbnw=107&prev=/images%3Fq%3Dconjugation%26gbv%3D2%26hl %3Den Bacterial reproduction Bacterial reproduction

26. http://images.google.com/imgres?imgurl=http://www.drnatura.com/img/good_bad_bact eria.jpg&imgrefurl=http://www.drnatura.com/flora_protect.php&h=248&w=389&sz=44& hl=en&start=3&tbnid=oCRN34FnS1MmzM:&tbnh=78&tbnw=123&prev=/images%3Fq %3Dgood%2Bbacteria%2Bin%2Bcolon%26gbv%3D2%26hl%3Den Good Bacteria

27. Good causing bacteria  E. Coli in stomach aids digestion  Benefit soil  Nitrification  Decomposition  Make acetone or butanol  To produce insulin, other chemicals  Clean oil spills  To clean ore  Yogurt, cheese, olives, vinegar, sourdough

28. Disease causing bacteria  Way 1: metabolize their host (destroy host cells)  Way 2: secrete poison as waste product

29. TUBERCULOSIS

30. STREP THROAT

31. LYME DISEASE

32. This bacteria can causes toxic shock syndrome (tampon use) and can also cause impetigo and pyoderma and is common in infant day care centers. SEM. Credit: © Dr. Gary Gaugler/Visuals Unlimited 19 73 76 Staphylococcus aureus

33. Archaeabacteria