1. Viruses!

2. What is a virus? A non-living particle composed of a protein coat (capsid) & nucleic acids The virus can have either DNA or RNA (retrovirus) as its nucleic acid.

3. Different types of viruses

4. Top 10 reasons why virus aren’t considered “living”… #10 Viruses do not grow

5. #9 Viruses can’t reproduce without a host

6. #8 Viruses do not maintain homeostasis

7. #7 Viruses do not have metabolism or require energy

8. #6 Viruses are not made of cells.

9. #5 Viruses mutate very quickly

10. #4 Viruses do not have any cell organelles

11. #3 Viruses need a host for everything

12. #2 Viruses are smaller than bacteria

13. #1 VIRUSES CAN NOT DO ANY OF THE FUNCTIONS OF LIFE & ARE NOT MADE OF CELLS!!

14. Viruses have 2 basic shapes 1)Icosahedron (has 20 triangular sides) EX: HIV  2)Helix – coiled spring EX: ebola 

15. Other virus-like things 1)Viroids – smallest things that can replicate, are pathogens. Made of small piece of RNA without the capsid. (cause plant diseases) 2)Prions – abnormal clumps of proteins, are pathogens. EX: “Mad cow disease”

16. How do viruses work? They hijack the cell and use it to make more viruses!

17. How do viruses reproduce? 1)Lytic cycle steps: a) virus attaches to cell receptor site b) injects its genetic material into cell. c) cell begins reading the viral DNA and makes more viruses. d) the cell is destroyed & new viruses are released to infect other cells

18. 2) Lysogenic cycle steps: a)Virus attaches to cell b)Injects the virus DNA into the cell & the DNA fuses with the cell’s DNA c)Cell keeps functioning as normal & does mitosis, each new cell will have the viral DNA d)Some signal starts the cells to making the viruses and the cells will be destroyed at one time.

19. Lytic & Lysogenic cycles

20. Viruses & diseases Most viruses act on specific types of cells. Plant viruses do not infect animals cells! Keep in mind that viruses can MUTATE very quickly to attack other types of cells though!!!

21. Some diseases that are caused by viruses… Polio HIV/AIDS Flus Measles Mumps Chickenpox Smallpox Hepatitis Herpes Ebola Colds

22. How can viruses be treated or prevented? Prevention: 1) vaccines (deactivated viruses) 2) good hygiene Treated: 1) symptoms can be treated 2) the body’s immune system will work on the virus

23. Some viruses can be helpful Bacteriophages (viruses that attack bacteria) are used in research. We figured out that DNA carries genetic info by using bacteriophages! Viruses can be used as VECTORS to carry “good” genes into a cell

24. Bacteriophage

25. HIV

26. Herpes

27. Smallpox