Viral capsid

Definition

A viral capsid is the protein shell that encases and protects the genetic material of a virus. It plays a crucial role in the infectivity and stability of the virus.

5 Must Know Facts For Your Next Test

1. The capsid is composed of protein subunits called capsomeres.
2. Capsids can exhibit different shapes such as helical, icosahedral, or complex structures.
3. The viral capsid not only protects viral nucleic acids but also facilitates their delivery into host cells.
4. Certain virulence factors are associated with the structural properties of the capsid, influencing how efficiently a virus can infect its host.
5. Some viruses have an additional lipid envelope surrounding the capsid, derived from host cell membranes.

Review Questions

• What are the primary functions of a viral capsid?
• How do capsomeres contribute to the structure of a viral capsid?
• In what ways does the shape of a viral capsid affect its pathogenicity?

Related terms

capsomere: Protein subunit that makes up the viral capsid.

viral envelope: Lipid membrane derived from host cell membranes that surrounds some viruses' capsids.

virion: Complete virus particle that includes both nucleic acid and a protein coat, and sometimes an envelope.