Question

One group of medications used to treat HIV infections is reverse transcriptase inhibitors. There are two types of these medications, nucleoside reverse transcriptase inhibitors (like AZT) and non-nucleoside reverse transcriptase inhibitors. AZT resembles thymine and is inserted into DNA during replication, leading to the termination of replication. Non-nucleoside reverse transcriptase inhibitors bind to reverse transcriptase and inhibit it in that manner. Non-nucleoside reverse transcriptase inhibitors tend to have fewer side effects. Which of the following best describes why this is the case?
a) Non-nucleoside reverse transcriptase inhibitors are less specific and therefore more effective.
b) Non-nucleoside reverse transcriptase inhibitors are less likely to stimulate cell growth.
c) Nucleoside reverse transcriptase inhibitors may interfere with DNA replication by the host, not just by the virus.
d) HIV can rapidly develop resistance to nucleoside reverse transcriptase inhibitors.

Answer 1

Answer:

c) Nucleoside reverse transcriptase inhibitors may interfere with DNA replication by the host, not just by the virus.

Explanation:

A drug that targets the structures or processes specific to the pathogen or microbe has fewer side effects than the drugs that target the more general structures and processes exhibited by both the pathogen and host cells.

According to the given information, the nucleoside reverse transcriptase inhibitors resemble thymine and terminate the process of DNA replication. Thymine base is also one of the nitrogenous bases present in the human cells and other organisms. Therefore, the nucleoside reverse transcriptase inhibitors would terminate the process of DNA replication in both the virus and the host organism.

On the other hand, the non-nucleoside reverse transcriptase inhibitors specifically target the reverse transcriptase enzyme that is not present in host organisms. Therefore, the non-nucleoside reverse transcriptase inhibitors have fewer side effects than the nucleoside reverse transcriptase inhibitors.