Describe viral replication - AQA - A-Level Biology - Question 4 - 2022 - Paper 1

Viral replication proceeds through several key stages:

1. Attachment: Attachment proteins on the virus bind to specific receptors on the surface of the host cell, facilitating entry into the cell. This step is crucial for identifying the target cell type.

2. Entry: The viral nucleic acid penetrates the host cell membrane and enters the cytoplasm. Once inside, it hijacks the host's cellular machinery.

3. Replication: The viral nucleic acid is replicated within the host cell. This can involve reverse transcriptase if the virus is retroviral, converting RNA to DNA, which is then integrated into the host's genome.

4. Assembly: New viral particles are assembled using the replicated nucleic acids and synthesized protein components (capsid and enzymes).

5. Release: Finally, the newly formed viruses are released from the host cell, often leading to cell lysis, which allows the virus to infect additional cells.