t/f HIV uses an enzyme called reverse transcriptase to synthesize complementary DNA from its RNA genome when in host cells
The Correct Answer and Explanation is:
True
HIV (Human Immunodeficiency Virus) is a retrovirus, meaning it carries its genetic information in the form of RNA rather than DNA. When HIV infects a host cell, it must convert its RNA genome into DNA in order to integrate into the host’s genome and replicate. This process is made possible by an enzyme called reverse transcriptase.
Reverse transcriptase is unique to retroviruses and plays a crucial role in the HIV life cycle. Once HIV enters a host cell, it releases its RNA genome along with reverse transcriptase. This enzyme catalyzes the synthesis of a complementary DNA (cDNA) strand from the viral RNA template. The process begins with the creation of a single-stranded DNA complementary to the viral RNA. Then, the enzyme degrades the original RNA strand and synthesizes a second DNA strand to form a double-stranded DNA molecule.
This newly synthesized viral DNA is then transported into the host cell’s nucleus, where it is integrated into the host’s genome by another enzyme called integrase. Once integrated, the viral DNA is transcribed and translated using the host’s cellular machinery, leading to the production of new viral proteins and RNA genomes. These components are assembled into new viral particles that bud from the host cell and go on to infect other cells.
The presence and function of reverse transcriptase are key targets in antiretroviral therapy. Many drugs designed to treat HIV aim to inhibit this enzyme, thereby preventing the virus from replicating. Reverse transcriptase inhibitors come in two main forms: nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs). By blocking the activity of reverse transcriptase, these drugs help reduce the viral load in HIV-positive individuals and slow the progression of the disease.
In summary, HIV’s use of reverse transcriptase is essential for its replication and is a defining characteristic of its classification as a retrovirus.
