1. Chapter 24 Video

2.  Computer Viruses?  Not in the scope of this class. They behave similarly, but are not at all related.

3. Section 24.1

4.  Late 1800’s – Something very small is causing diseases!  1935 – It is not made of cells (living things). TMVPolioHIV

5.  A nonliving particle composed of a nucleic acid and a protein coat.  Study of viruses = virology

6.  Cause disease in living organisms  Useful tools for genetic research

7. The Characteristic of life: growth homeostasis metabolism organization cells reproduction  Viral characteristics: NO YES NO within host cell NOPE!

8.  AIDS  Influenza  Chickenpox  Rabies  Polio  Mumps  Colds

9.  All viruses have: 1. Nucleic acid: (DNA or RNA) 2. Capsid: protein coat  Some viruses have: 1. Glycoprotein projections: signals 2. Envelope: Bilipid membrane surrounding the capsid. Can fit “lock-and-key” with receptors on host cell.

12. SHAPE AND STRUCTURE:  Envelope present or not?  DNA or RNA?  Single stranded or double stranded?  How does it affect a human? RabiesHepatitus Herpes

13.  Size:  20 to 250 nm  Cannot be seen by a light microscope  How big is this? Think about it.  Shape:  Determined by the genome (DNA/RNA) or capsid (protein)

14. H1N1 or influenza Video

15. Obligate Intracellular Parasites (huh?)

16.  DNA viruses:  DNA  mRNA  proteins  Provirus: inserted viral DNA into host cell  RNA viruses:  mRNA  protein  Retroviruses:  RNA  DNA  mRNA  protein  Reverse transcriptase: enzyme  Example: HIV

17.  Bacteriophage: virus that infects bacteria  Helped scientists discover how viruses replicated  Two replication cycles  Lytic cycle: virulent  Lysogenic cycle: temperate

18. LYTICLYTIC CYCLECYCLE Animation

19. LYSOGENICLYSOGENIC CYCLECYCLE

20.  Early viruses evolved from early cells  Viruses mutate quickly and frequently  Thus they evolve quickly  New strains formed this way

21. Section 24.2 Flu Video

22.  An intermediate host that transfers pathogens from one organism to another  Examples:  Humans  Animals  mosquitoes  Fleas  ticks

23.  Virus: varicella-zoster herpesvirus  Symptoms: rash & fever  Replication: Multiplies in lungs and uses blood network to reach skin  Transmission: direct contact with skin rash

24.  Virus: Hepatitis A, B, C, D, E  Symptoms:  Fever, nausea, jaundice, liver failure  Transmission:  Sexual contact (B,C,D)  Fecal matter in food & water (A,E)

25.  Virus: HIV (Human Immunodeficiency Virus)  retrovirus  Transmission: through bodily tissues and fluids  Symptoms: weakened immune system  Treatment: Drugs target reverse transcriptase OR stop new capsids from forming (protease inhibitors).

27.  Cancer: when cells divide at an uncontrolled rate and form a tumor  Oncogenes: viral genes that cause cancer  Examples:  HPV  cervical cancer  Hepatitis B  liver cancer  Epstein-barr  lymphoma

28.  New viruses are being discovered every year as humans alter ecosystems  Examples:  HIV  Ebola  SARS  West Nile

29. 1. Vaccinations: to prevent disease  Inactivated or attenuated  Smallpox eradication 2. Vector Control: Wildlife population control 3. Drug Therapy: Interfere with viral nucleic acid

30. 1. Wash your hands! 2. Don’t share tools (cups, toothbrushes) 3. Use protection when transmitting bodily fluids 4. Don’t become someone’s “Blood brother” 5. Avoid being bitten by any animal 6. Cover your mouth when sneezing

31. Viroids – a short singular strand of RNA  smallest known particle to cause disease  infects mostly plants Prions - protein particles without a genome  mad cow disease

33.  You would expect the members of the bacterial genus Bacillus to be what type of shape?

34.  Check out this game about viral outbreaks  https://itunes.apple.com/us/app/solve-the- outbreak/id592485067?mt=8