Microbiology Practice Exam

What is the primary function of reverse transcriptase?

1. Converts DNA to RNA

2. Converts RNA to DNA

3. Replicates DNA

4. Transcribes RNA

The correct answer is: Converts RNA to DNA

The primary function of reverse transcriptase is to convert RNA into DNA. This enzyme is most commonly associated with retroviruses, such as HIV. In these viruses, reverse transcriptase synthesizes complementary DNA (cDNA) from the viral RNA genome. Once the RNA template is converted into cDNA, this newly formed DNA can integrate into the host cell's genome, allowing for viral replication and proliferation. This process is a critical step in the life cycle of retroviruses, enabling these pathogens to hijack the host's cellular machinery for their own replication. Unlike transcription, which involves converting DNA into RNA, reverse transcription is the reverse process, hence the name "reverse transcriptase." The other options describe functions that are not performed by reverse transcriptase, further underscoring the uniqueness of its role in molecular biology and virology.