Introduction to HIV and AIDS - Day 11

Objective: Students will be able to explain what a retrovirus is and how it works.

Student answers will vary depending on background and experience studying
HIV and AIDS

Part 1 - Research

This image is of a basic viral life cycle / This image is how a retrovirus (like HIV) works

Comparing viruses and retro-viruses

Question / Viruses / Retroviruses
How is step 1 different for a virus and a retrovirus? / The virus attaches itself to the host and injects its' DNA / The retrovirus enters the host, releases its' RNA
How is step 2 different for a virus and a retrovirus? / The virus' DNA destroys the host cell DNA / The retrovirus RNA is turned into DNA and the DNA enters the host's nucleus and the host's DNA
How are viruses and retro-viruses different in how they treat the host DNA? / The Viral DNA destroys the host DNA / The retrovirus joins the host DNA
What happens during stage 3 for both a virus and a retrovirus? / The virus gets the host cell to start making viral parts / The retrovirus gets the host cell to start making retroviral parts
How are the final stages different for viruses and retroviruses? / The virus explodes the host cell with viral particles / The retrovirus does not destroy the host cell right away

Analysis

  1. Take a look at the virus life cycle again. What do you think reverse transcriptase does to the viral RNA? Where does this changed RNA go?

Reverse transcriptase converts the viral RNA into DNA.
The viral DNA joins the host DNA in the nucleus.
  1. HIV can be dormant for up to 15 years. Why do you think it can hide so well?

The virus can hide in the host nucleus and could not be seen by any white
blood cells.
  1. Mitosis is the process of cells making new exact duplicates of the original cell by duplicating all of the DNA in the cell. How does this process help the virus?

Every time the host cell replicates, it also replicates the viral DNA. This could
leave the organism with thousands of copies of the viral DNA

Conclusion

Use your new-found knowledge to answer the question: Why do you think HIV/AIDS is so much more dangerous than most other sexually transmitted viruses?

Answers will vary, but look for the following key terms or phrases:
  • Retrovirus enters the host cell

  • Reverse transcriptase

  • Viral DNA joins host DNA

  • Host DNA replicates the viral DNA every time the host replicates

  • Virus production does not destroy the cell right away