IMAT 2014 Q33 [Human Immunodeficiency Virus]

Which of the following molecules are associated with the Human Immunodeficiency Virus (HIV)?

  1. DNA
  2. RNA
  3. Phospholipids
  4. Reverse transcriptase

A. 1 and 2 only
B. 2 and 3 only
C. 1, 2 and 4 only
D. 1, 2, 3 and 4
E. 2, 3 and 4 only

The correct answer for this question is choice E.

This question requires you to be familiar with the structure of HIV, which will help you either include or eliminate choices within you consideration:

  • HIV or the human immunodeficiency virus, is part of the family retroviridae, which is a family of positive single-stranded RNA viruses. Another virus that belongs to this family is the HLTV or the human T-cell lymphotropic viruses. This then eliminates #1 from your considerations, and further strengthens that #2 is a correct association with HIV.
  • Various viruses, including viruses that belong to the retroviridae family, are surrounded by a continuous bilayer membrane with accompanying viral proteins. This bilayer configuration would not be possible if phospholipids were completely absent, thus this makes #3 as a correct association with HIV.
  • A significant contribution to the virulence of HIV are the different structural proteins that HIV has. One of which, is an important gene called the pol gene that codes for a polyprotein that includes proteases, integrases, which help insert the viral genes into the host, and the reverse transcriptase, which is an enzyme the virus family retroviridae is well known for. This enzyme converts viral RNA into dsDNA, which is the opposite of the known process of transcription, which is why it is called reverse trascriptase.

Thus knowing the basic structure of HIV, it now makes sense why the correct answer is choice E.