Difference between Virus and Virion (original) (raw)
Last Updated : 23 Jul, 2025
The difference between virus and virion is that virus is the nucleoprotein particle whereas virion is the active, infectious form of the virus. A virus consists of genetic material encased by a protein capsid. It does not show any metabolic activity. Virion is the vector stage of a virus, which permits the transmission of a virus from one infected host cell to another.
Therefore, the virus is the intracellular phase whereas virion is the extracellular phase of the virus. Both virus and virion are two kinds of microscopic, obligatory parasites that are infectious. In this article, we will study the **difference between a virus and a virion, **what a virus is, the **characteristics of a virus, **what a virion is, and the **similarities between a virus and virion.
Table of Content
- Difference Between Virus and Virion
- What is a Virus?
- What is a Virion?
- Similarities Between Virus and Virion
- Conclusion: Difference between Virus and Virion
Difference Between Virus and Virion
The table below highlights the differences between virus and virion:
| Features | **Virus | **Virion |
|---|---|---|
| **Definition | Virus is a small parasite that consists of a nucleic acid molecule covered by a protein coat. | Virion is the complete, infective form of a virus outside the host cell. They consist of both nucleic acid and protein layers. |
| **Significance | Virus is a nucleoprotein particle and a non-cellular entity. | Virion is the infectious form of a virus. |
| **Intracellular/Extracellular | Virus is the intracellular parasite. | Virion is the extracellular parasite. |
| **Size | Virus is comparatively larger than a virion. | Virion is smaller than the virus. |
| **Shape | The shapes of a virus are helical, icosahedral, prolate, envelope, and complex. | Most virions are spheroidal or rod-shaped. |
What is a Virus?
A virus is a **minute, non-cellular structure comprising of a nucleic acid molecule covered by a protein coat. It is an intracellular parasite. It has the ability to proliferate and invade the living cells of plants, animals, and other microorganisms; however, it can only replicate itself within a particular host cell. A virus particle typically consists of a single-stranded or double-stranded, DNA or RNA genome, covered by a protein coat called capsid. Viruses have various sizes spanning from **10–400 nm in diameter.
They are considered to be **non-living entities when outside the host cell as they do not show any metabolic activity. As such, they belong to a unique category that cannot be distinctly classified as either living or non-living. A virus is comparatively larger than a virion and may have different shapes. It can be helical, prolate, envelope, complex or icosahedral among others.
Characteristics of Viruses
Following are a few characteristic of viruses:
- A cell nucleus is absent.
- Their cell structure is **disorganized.
- They usually consist of one or two strands of DNA or RNA.
- They are covered in a protective protein coat called capsid.
- They are able to reproduce even though they cannot grow, respire, or metabolize.
- They are **considered both living and non-living since they are inactive outside the host cell and become active within the host cell.
Also Read: Virus in Biology
What is a Virion?
A virion is not the same as a virus but it is a virus in its extracellular phase. It is the **complete, active, infectious form of a virus that exists outside the host cell. It is an **extracellular parasite. It is composed of **either a **DNA or RNA genome, and is encased in an outer protein shell termed as **capsid. It also contains an additional outer membrane made up of lipids called the envelope.
**Virion is relatively smaller than the virus and is typically **spheroidal in shape. The majority of plant viruses have **rod-shaped virions. Virions perform the function of securely transporting the virus from the original host to a new host. Additionally, they also protect the genetic material from external threats.
Similarities Between Virus and Virion
Following are the similarities between virus and virion:
- The genetic material of both viruses and viron is made up of DNA or **RNA.
- A **protein coat envelops both virion and virus.
- Virion and viruses are both **self-replicating entities.
- Both virus and virion are **non-cellular entities that are host specific.
- Both virus and virion exhibit **lower levels of metabolic activity.
Conclusion: Difference between Virus and Virion
A virus is a broader term that encompasses the entire infectious agent, including its various stages of the life cycle (inside and outside the host cell). On the other hand, a virion specifically refers to the extracellular, infectious form of a virus, which is the particle responsible for initiating new infections.
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