Envelope

Definition

An envelope is a lipid bilayer membrane that surrounds the capsid of some viruses. It is derived from portions of the host cell membranes and may contain viral glycoproteins.

5 Must Know Facts For Your Next Test

1. The viral envelope helps the virus bind to and enter host cells.
2. Enveloped viruses are typically more sensitive to environmental conditions like desiccation, heat, and detergents compared to non-enveloped viruses.
3. Glycoproteins embedded in the envelope play crucial roles in host specificity and immune evasion.
4. The process of budding allows enveloped viruses to acquire their envelopes from the host cell’s membrane.
5. Common examples of enveloped viruses include influenza, HIV, and herpesviruses.

Review Questions

• What is the primary function of a viral envelope?
• Why are enveloped viruses generally more sensitive to environmental conditions than non-enveloped viruses?
• How do glycoproteins in the viral envelope aid in infection?

Related terms

Capsid: The protein shell that encloses the genetic material of a virus.

Glycoprotein: A molecule consisting of a protein and carbohydrate that often serves as a receptor or antigen on the surface of cells or viruses.

Budding:

A process by which certain viruses acquire their envelopes by pinching off a portion of the host cell membrane.