🦠microbiology review

Viral capsid

Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025

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.

AP course connection

Topic 15.3: 15.3 Virulence Factors of Bacterial and Viral Pathogens

Unit 15

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.
2,589 studying →