Describe that viruses can only replicate in living cells

Sourav PanNovember 2, 2024

Answered

Viruses are unique infectious agents that can only replicate within living cells, relying entirely on the host’s cellular machinery for their reproduction. Here are the key points that explain this characteristic:

1. Obligate Intracellular Parasites: Viruses are classified as obligate intracellular parasites, meaning they must enter a living host cell to reproduce. Outside of a host, they exist as inert particles called virions and cannot carry out any metabolic processes or replicate on their own.
2. Lack of Cellular Machinery: Viruses do not possess the cellular structures necessary for metabolism or protein synthesis, such as ribosomes and enzymes. Instead, they hijack the host cell’s machinery to replicate their genetic material and produce viral proteins. This dependence on the host’s cellular environment is a defining feature of viruses.
3. Replication Process: The replication cycle of a virus involves several stages:
   • Attachment: The virus binds to specific receptors on the surface of a host cell.
   • Entry: The viral genome enters the host cell.
   • Uncoating: The viral capsid is removed, releasing the viral genetic material.
   • Replication: The virus uses the host’s cellular machinery to replicate its genome and synthesize viral proteins.
   • Assembly: New viral particles are assembled from the replicated genetic material and proteins.
   • Release: Newly formed virions exit the host cell, often destroying it in the process, to infect new cells.
4. Diversity of Hosts: Viruses can infect a wide range of living organisms, including animals, plants, and bacteria. Each virus has evolved to target specific types of cells within these hosts.