Viruses and Bacteria

1. Viruses and Bacteria Differences between bacteria and viruses: http://www.youtube.com/watch?v=s-HThHRV4uo http://www.youtube.com/watch?v=Rpj0emEGShQ- how the flu attacks your body

2. What makes a cell living and a virus non living! • What is a microbe? • What is a pathogen? Measles outbreak interactive map: http://www.cfr.org/interactives/GH_Vaccine_Map/#map

3. Bubonic (Black) Plague Bubonic plague is one of the deadliest pandemics in human history. It killed 30-60% of Europe’s population between 1348-1350 and took 150 years for Europe's population to recover.

4. AIDS/HIV Since AIDS was first recognized in 1981, it has led to the deaths of more than 25 million people, making it one of the most destructive diseases in recorded history.

5. Yogurt Dairy product produced by fermentation of milk. People have been making and eating yogurt for atleast 5,500 years!

6. Swine Flu Global outbreak that began in Mexico, approximately 600,000 people infected world-wide.

7. Humulin Humulin was the first medication produced using modern genetic engineering techniques in which actual human DNA is inserted into a host cell. The host cells are then allowed to grow and reproduce normally, and due to the inserted human DNA, they produce a synthetic version of human insulin. Humulin can be used as a treatment for diabetes.

8. Characteristics of Bacteria • Unicellular • Prokaryotic • Can be autotrophs or heterotrophs • Can be aerobic (uses oxygen) or anaerobic • Can be motile or non-motile • For motility bacteria have cilia or flagella

9. Bacillus Bordetella Clostridium Escherichia Spirulina Staphylococcus Streptococcus Salmonella Bacteria come in a wide range of shapes, sizes and colours!

10. Bacterial growth and reproduction • Asexual reproduction is called binary fission • Sexual reproduction is called conjugation • Some bacteria also form endospores to survive harsh conditions and then germinate when conditions become favorable

11. Binary Fission 1 bacterium can become 1/2 million in 6-7 hours Based on Harvard Medical School Family Health Guide

12. Reproduction • Conjugation- Exchanging genetic information in which a hollow bridge forms between two bacteria cells and genes are passed. This increases genetic diversity.

13. Examples of good bacteria • We depend on Escherichia coli in our intestines to provide us with Vitamin K and B Complex vitamins. • Lactobacillus bulgaricus found in cheese and yogurt. • Aids in the digestion of lactose by producing the enzyme lactase. • Boosts the immune system

14. Pathogenic (harmful) bacteria cause disease by destroying cells or by producing toxins that stop the cell from doing its job • Staphylococcus aureus-food poisoning when toxins are ingested • Streptococcus pyogenes-causes strep throat—red spots on your throat are red blood cells the bacteria have destroyed • Clostridium botulinum-produces toxins that cause paralysis for 4-6 months (botox injections are made of these toxins!!!)

15. Controlling Bacterial Growth • Pasteurization is used to remove bacteria from food • Antiseptics can kill bacteria on tissues • Antibiotics are used to kill bacteria that have entered the body • Vaccines can prevent bacterial infections by stimulating the immune system

16. How bacteria get ENERGY? • Some are AUTOTROPHS, meaning they make their own food from inorganic molecules. • Photoautotrophs which use light energy to convert carbon dioxide and water to carbon compounds and oxygen in a process similar to that used by plants. • Chemoautotrophs which uses energy directly from chemical reactions involving ammonia, hydrogen sulfide, nitrates, sulfur and iron. • Bacteria that needs oxygen to live= obligate aerobes. • Bacteria that can survive without oxygen=facultative anaerobes.

17. Draw a picture of a bacterium on your notes

18. A Virus is: • A non-living parasite • Made of nucleic acids, proteins, and sometimes lipids • Highly specific to the types of cells they infect (bacteriophages are viruses that infect bacteria) • Do not obtain or use energy; Depends entirely on a host to survive • Able to evolve

19. Size

20. Viral Structure • Inner core of nucleic acid, either RNA or DNA; containing information to make copies of the virus • Outer protein coat called a capsid • Large viruses have envelope surrounding capsid

21. Virus shape depends on arrangement of capsidprotiens

22. What a virus does A non-living, disease causing parasite that invadesthe cell. It turns the cell into a virus making factory until it no longer needs the cell. It then destroys the cell releasing new viruses to continue the cycle. http://www.youtube.com/watch?v=Rpj0emEGShQ

23. Virus Replication • Once attached to the plasma membrane of the host cell, the virus enters the cell and takes over its metabolism. Only then can the virus replicate.

24. Viral Reproduction http://www.tvdsb.on.ca/westmin/science/sbi3a1/Bacvirus/Virusrep.htm

25. Viruses have two ways of getting into host cells. • The virus may inject its nucleic acid into the host cell like a syringe injects a vaccine into your arm • An enveloped virus enters a host differently. After attachment, the plasma membrane of the host cell surrounds the virus and produces a virus-filled vacuole inside the host cell’s cytoplasm. Then, the virus bursts out of the vacuole and releases its nucleic acid into the cell.

26. Lytic Cycle • A typical lytic cycle takes about 30 minutes and produces about 200 new viruses. • The viral genes alter the host cell to make new viruses. The host cell uses its own enzymes, raw materials, and energy to make copies of viral genes that along with viral proteins are assembled into new viruses, which burst from the host cell, killing it.

27. Lytic cycle

28. Lysogenic cycle • Does not kill cell like lytic cycle does • Begins like the lytic cycle. The virus attaches to the host cell’s plasma membrane and its nucleic acid enters the cell. • Instead of immediately taking over the host’s genetic material, the viral DNA is integrated into the host cell’s chromosome.

29. Lysogenic cycle continued • Viral DNA that is integrated into the host cell’s chromosome is called a provirus. • A provirus may not affect the functioning of its host cell. • Every time the host cell reproduces, the provirus is replicated along with the host cell’s chromosome. Therefore, every cell that originates from an infected host cell has a copy of the provirus.

30. Lysogenic cycle continued • The lysogenic phase can continue for many years. However, at any time, the provirus can be activated and enter a lytic cycle. Then the virus replicates and kills the host cell. • Process explains the reoccurrence of cold sores, which are caused by the herpes simplex I virus. • Even though a cold sore heals, the herpes simplex I virus remains in your cells as a provirus. When the provirus enters a lytic cycle, another cold sore erupts. • Physical and emotional stress play a role in activating a provirus • Chicken pox and shingles

31. Lytic and Lysogenic cycles

32. A virus is NOT: • Alive • Capable of reproducing on its own • Capable of growing and developing during its ‘life’ cycle

33. Common Viral Diseases • Rhinoviruses cause the common cold • HPV (Human papillomavirus) can cause cervical cancer in women • Herpes simplex viruses cause mouth and/or genital sores, lesions, and ulcers. • Influenza viruses cause the flu • HIV (Human Immunodeficiency Virus) causes AIDS and weakens the immune system http://www.youtube.com/watch?v=YSgkoldBNkI

34. Controlling Viruses • Antibiotics DO NOT work on viruses. • Most human viral infections can be fought off by the immune system—boost the immune system with lots of water and rest. • Vaccines are preventative!!!

35. Controlling Viruses • Vaccines will NOT cure you if you are already sick. • Vaccines stimulate the immune system to create antibodies that recognize a certain virus. • These antibodies patrol your body and if they recognize that virus…they call in reinforcements and your immune system goes to battle!

36. Virus Attachment • A virus recognizes and attaches to a host cell when one of its proteins interlocks with a molecular shape that is the receptor site on the host cell’s plasma membrane. • The recognition and attachment process is like two pieces of a jigsaw puzzle fitting together.

37. DNA viruses: herpes simplex virus (HSV)

38. Varicella zoster virus (VZV) • VZV: Chickenpox • VZV: Shingles • Re-activation of latent infection

39. RNA viruses: Ebola • Ebola hemorrhagic fever (Ebola HF) is a severe, often-fatal disease in humans and nonhuman primates • Appeared sporadically since its initial recognition in 1976. • Transmission arthropod bites. • No known treatment.

40. Retrovirus • A retrovirus is an RNA virus that is replicated in a host cell via the enzyme reverse transcriptase to produce DNA from its RNA genome. • The DNA is then incorporated into the host's genome. The virus thereafter replicates as part of the host cell's DNA. • HIV is a retrovirus

41. Plant viruses • The first virus to be identified was a plant virus, called tobacco mosaic virus • 400 identified viruses that infect plants with 1000 different diseases • Cause stunted growth and crop losses

42. Draw a picture of a virus on your notes

43. Classified into the Kingdom Eubacteria or Archeabacteria NOT classified because THEY ARE NOT ALIVE Viruses vs. Bacteria