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  1. Virus

  2. So what do we already know about VIRUSES?

  3. V: Introduction to Viruses

  4. What is a “Pathogen”? Definition: a disease causing agent.

  5. What is a “Virus”? Definition: a pathogen, or disease causing agent, not considered living because it cannot reproduce on its own.

  6. Virus Reproduction A virus must have a HOST CELL to reproduce.

  7. Structure of a “Virus” Capsid: outer protein coat. Genetic Material: DNA or RNA.

  8. V: Invasion of the Virus

  9. “Lytic Cycle” Definition: process in which a virus enters a cell, makes a copy of itself, and causes the cell to burst.

  10. “Lytic Cycle” (Viral Reproduction)

  11. “Stage A (1)” The virus lands on the host cell and then injects its genetic material into the host cell.

  12. “Stage B (2)” The virus using the host cell to synthesize, or make, viral proteins (capsids) and nucleic acids (genetic material-DNA or RNA).

  13. “Stage C (3)” The virus assembles (puts together) capsidsand nucleic acids to prepare for release.

  14. “Stage D (4)” The host cell breaks open (lysing) and the newly assembled viruses begin to be released.

  15. V: Bacteriophage Lytic Cycle

  16. “Lysogenic Cycle” Definition: process by which a virus embeds its DNA into the DNA of the host cell and is replicated along with the host cell's DNA. Lysogenic cycle is a viral reproduction cycle in which the virus is dormant until it enters the lytic cycle.

  17. “Lysogenic Cycle”

  18. What is a “Retrovirus”? Definition: a virus that contains RNA as its genetic material instead of DNA.

  19. Viruses cause “Disease” How: by disrupting the body’s normal equilibrium. In many viral infections, viruses attach and destroy certain cells in the body, causing the symptoms of the disease.

  20. “HIV” (Human Immunodeficiency Virus) Definition: retrovirus that destroys white blood cells called helper T cells and causes the disease known as AIDS (Acquired Immune Deficiency Syndrome).

  21. “Influenza” (Flu or Grippe) Definition: a highly infectious respiratory disease. Your best defense against this virus is to receive an annual vaccination (according to the Mayo Clinic).

  22. What is a “Vaccine”? Definition: a preparation of weakened or killed pathogens. When injected into the body, a vaccine sometimes prompts the body to produce immunity to the disease.

  23. V: How Vaccines Work

  24. What is “Immunity”? Definition: the body's ability to destroy new pathogens.

  25. What are “Antibiotics”? Definition: compounds that block the growth and reproduction of bacteria. DO NOT work on viral infections!

  26. Who is a “Immunologist”? Definition: a person who specializes in the immune system, to study the mechanism used by the virus to infect cells. If a company wants to develop antiviral drugs, they would need to ask a research immunologist.