Enveloped Virus

Definition

An enveloped virus is a type of virus that has an outer lipid membrane, derived from the host cell it infects, surrounding its protein coat or capsid. This envelope plays a crucial role in the virus's ability to enter host cells, as it facilitates fusion with the host cell membrane. The presence of an envelope also influences how the virus is transmitted and can affect its susceptibility to environmental factors and antiviral treatments.

5 Must Know Facts For Your Next Test

1. Enveloped viruses include notable examples like HIV, influenza virus, and herpes simplex virus, all of which rely on their envelopes for infectivity.
2. The envelope is sensitive to heat, detergents, and desiccation, making enveloped viruses generally less stable in the environment compared to non-enveloped viruses.
3. Enveloped viruses often use glycoproteins on their surface to bind to specific receptors on host cells, a critical step for initiating infection.
4. Transmission routes for enveloped viruses can include respiratory droplets, sexual contact, and blood, largely influenced by the stability of the envelope.
5. Antiviral treatments often target the viral envelope, disrupting its integrity or blocking glycoprotein interactions with host cells.

Review Questions

• How does the structure of an enveloped virus influence its ability to infect host cells?
  • The structure of an enveloped virus includes a lipid membrane derived from the host cell, which is essential for its ability to infect other cells. This envelope facilitates the fusion process between the viral membrane and the host cell membrane. When an enveloped virus encounters a suitable host cell, its glycoproteins can specifically bind to receptors on that cell's surface. This interaction allows the virus to enter the host cell and begin the replication cycle.
• What are some differences between enveloped viruses and non-enveloped viruses regarding their stability and transmission routes?
  • Enveloped viruses are generally more fragile than non-enveloped viruses due to their lipid membranes, which can be easily disrupted by heat and detergents. This makes enveloped viruses less stable in harsh environments compared to non-enveloped viruses that have a more robust protein capsid. In terms of transmission routes, enveloped viruses often spread through direct contact or respiratory droplets due to their sensitivity to desiccation, while non-enveloped viruses may survive longer outside a host and can be transmitted via contaminated surfaces.
• Evaluate the role of glycoproteins in the infectivity of enveloped viruses and their potential as targets for antiviral therapies.
  • Glycoproteins on the surface of enveloped viruses are crucial for their infectivity because they mediate the binding between the virus and specific receptors on host cells. This binding is essential for viral entry and subsequent infection. Given their pivotal role in the viral life cycle, glycoproteins present attractive targets for antiviral therapies. By designing drugs or antibodies that inhibit these glycoprotein interactions or disrupt their function, researchers aim to block viral entry into host cells and mitigate infection spread.

Related terms

Capsid: The protein shell that encases and protects the viral genetic material, playing a vital role in the virus's structure and function.

Viral Replication: The process by which a virus reproduces within a host cell, involving attachment, entry, replication, assembly, and release.

Glycoproteins: Molecules found on the surface of enveloped viruses that assist in recognizing and binding to host cell receptors, facilitating viral entry.