In an enveloped virus, what is the primary function of the surface projections (spikes/peplomers)?

• A. Prevent mutation by proofreading newly copied viral genomes
• B. Mediate attachment to specific host cell receptors and promote entry into the host cell
• C. Synthesize viral nucleic acids and proteins using viral ribosomes
• D. Provide energy for viral replication by carrying out ATP production

Answer: (B)

Verified step by step guidance

1. Understand that enveloped viruses have a lipid bilayer membrane derived from the host cell, which contains embedded proteins called surface projections or spikes (also known as peplomers).
2. Recognize that these surface projections are specialized glycoproteins that extend from the viral envelope and interact with the external environment.
3. Identify the role of these spikes in the viral life cycle, particularly their involvement in recognizing and binding to specific receptors on the surface of potential host cells.
4. Know that this binding is crucial because it determines the virus's host range and initiates the process of viral entry into the host cell, often by facilitating membrane fusion or endocytosis.
5. Conclude that the primary function of the surface projections is to mediate attachment to specific host cell receptors and promote entry into the host cell, rather than functions like proofreading, nucleic acid synthesis, or energy production.