Virion

Definition

A virion is a complete virus particle that consists of an RNA or DNA core with a protein coat and, in some cases, other layers. It is the extracellular form of a virus that can infect host cells.

5 Must Know Facts For Your Next Test

1. Virions are responsible for the transmission of viral genetic material between hosts.
2. They can be composed of either single-stranded or double-stranded RNA or DNA.
3. The protein coat surrounding the nucleic acid is known as a capsid.
4. In some viruses, the virion also includes an envelope derived from the host cell membrane.
5. Virions are not capable of metabolic activity and must infect a host cell to replicate.

Review Questions

Related terms

Capsid:

The protein shell that encloses the viral genome.

Envelope:

A lipid membrane derived from the host cell that surrounds some viruses.

Nucleocapsid: The combination of viral nucleic acid and capsid proteins within a virion.