USA Biology Olympiad (USABO) Practice Exam

What enzyme does HIV use to convert RNA to DNA?

1. DNA Polymerase

2. Reverse Transcriptase

3. RNA Polymerase

4. Ligase

The correct answer is: Reverse Transcriptase

HIV, or Human Immunodeficiency Virus, is a retrovirus that relies on a specific enzyme known as reverse transcriptase to convert its viral RNA genome into DNA. This process is essential for the virus to integrate its genetic material into the host cell's DNA and replicate within the host. Reverse transcriptase functions by transcribing RNA into complementary DNA (cDNA). The resulting DNA can then be incorporated into the host's genome, allowing the virus to hijack the cellular machinery for its replication. This process is a hallmark of retroviral infections, distinguishing them from other types of viral replication. Other enzymes mentioned in the options have different roles. DNA polymerase synthesizes DNA from nucleotides during DNA replication but does not perform reverse transcription. RNA polymerase synthesizes RNA from a DNA template, which does not apply in the case of converting RNA into DNA. Ligase is involved in joining DNA strands together, which is also not relevant to the process of reverse transcription. Understanding the function of reverse transcriptase in HIV's life cycle highlights the target for certain antiviral therapies, making it a critical area of study in virology and infectious diseases.