Why is HIV called a retrovirus?
The Human Immunodeficiency Virus (HIV) is called a retrovirus because the RNA genome transcribes or copies back into the DNA in the host cell. This is by way of reverse transcriptase - a viral enzyme. HIV can only replicate itself within living cells. It uses cells' replication enzymes to makes these copies of itself. The reverse transcriptase enzyme copies the retroviral RNA into DNA.
DNA is the genetic material of living organisms; RNA is genetic material that is typically single-stranded. The HIV virus infects cells of the immune system. Its terrible effect is that it destroys these cells. In addition, this retrovirus destroy's the immune system's ability to fight off invaders that seek to compromise the immune system and cause health problems.
In essence, retroviruses have a unique method of reproduction. Retroviruses utilize the enzyme (protein catalyst) reverse transcriptase (RT) to incorporate their genetic material (RNA) into the genetic material (DNA) of the infected host's cells. The DNA subsequently undergoes incorporation into the host cell chromosome. Consequently, when the retrovirus integrates its genetic material with the host's, it become's part of the host's genome for life.
Retroviruses, belonging to the Retroviridae family, carry their genetic information in RNA. Most cellular organisms carry their genetic material in the aforementioned DNA.