Question

Place the following events of HIV infection of a cell in sequence from first to last.

1) Viral RNA is converted to single-stranded viral DNA with the assistance of reverse transcriptase.
2) Viral DNA is sliced into the cell genome using the enzyme integrase.
3) GP120 proteins on the viral envelope combine with CD4 receptors of body cells.
4) Cell replicates infected daughter cells and makes more HIV.
5) Viral RNA and reverse transcriptase enzyme enter host Cd₄⁺ T cell.
6) Long strands of viral RNA are cut in the presence of protease.
7) Single-stranded viral DNA replicates into double-stranded DNA.

Answer 1

The correct sequence of HIV infection begins with GP120 proteins attaching to CD4 receptors, followed by the entry of viral RNA and enzymes into the host cell, reverse transcription into single-stranded DNA, replication into double-stranded DNA, integration into the host genome, protease activity, and finally, the replication of new HIV particles.

Step-by-step explanation:

Sequence of HIV Infection of a Cell

The sequence of an HIV infection of a cell is a complex process that involves various stages. Let's place the events in the correct order:

1. GP120 proteins on the viral envelope combine with CD4 receptors of body cells. This is the initial attachment of the virus to the target cell.
2. Viral RNA and reverse transcriptase enzyme enter host CD4+ T cell. The virus fuses with the cell membrane, allowing its contents to enter the cell.
3. Viral RNA is converted to single-stranded viral DNA with the assistance of reverse transcriptase. This is the reverse transcription process that converts the viral RNA into DNA.
4. Single-stranded viral DNA replicates into double-stranded DNA. After the first DNA strand is synthesized, a second DNA strand complements the first.
5. Viral DNA is inserted into the cell genome using the enzyme integrase. This integrated DNA is known as a provirus.
6. Long strands of viral RNA are cut in the presence of protease. This step involves the processing of the viral proteins necessary for the assembly of new virions.
7. Cell replicates infected daughter cells and makes more HIV. The provirus uses the host cell's machinery to produce more viral particles, which are then released to infect other cells.

The HIV infection process is a critical target for antiretroviral drugs, which can inhibit enzymes like reverse transcriptase and integrase, thus preventing the replication of the virus and the onset of AIDS.