1. After infecting host cells, how does the AIDS virus, which contains RNA, insert viral DNA into the host T-cell?
Answer: B
The AIDS virus inserts viral DNA into the host T-cell using reverse transcriptase.
Reverse transcriptase is an enzyme that the AIDS virus encodes, which facilitates the conversion of viral RNA into DNA after the virus infects a host cell. This step is crucial for the integration of the viral genome into the host's DNA.
A) Receptor proteins located on the surface of the virus
Receptor proteins are involved in the initial attachment of the virus to host cells, allowing entry into the cell. However, they do not play a direct role in the process of inserting viral DNA; thus, this option is incorrect.
B) Reverse transcriptase, an enzyme encoded by the virus
Reverse transcriptase is the correct answer, as it is the enzyme responsible for synthesizing DNA from the viral RNA. This enzyme catalyzes the reverse transcription process, which is essential for the integration of viral genetic material into the host's genome.
C) The phospholipids found on the envelope of the virus
Phospholipids in the viral envelope facilitate the fusion of the virus with the host cell membrane, allowing entry into the cell. However, they do not contribute to the insertion of viral DNA into the host T-cell, making this option incorrect.
D) The protein that makes up the capsid of the virus
The capsid protein protects the viral RNA and enzymes but is not involved in the direct process of inserting viral DNA into the host cell. Therefore, this option is also incorrect.
Conclusion
Reverse transcriptase is critical for the conversion of viral RNA to DNA, allowing the AIDS virus to successfully integrate into the host's genetic material. The other options focus on different aspects of viral infection and entry, but none are involved in the critical process of DNA synthesis and integration, which is why B is the definitive correct choice.