Question

The envelope of a virus is derived from the host's a. nucleic acids b. membrane structures c. cytoplasm d. genome

Short answer

The correct answer is b. membrane structures.

Step-by-step solution

Understand the Question

Identify the main elements of the question. It asks from where the envelope of a virus is derived, providing four choices: nucleic acids, membrane structures, cytoplasm, or genome.

Analyze Each Option

Examine each option to see if it accurately describes the origin of the virus envelope. Consider the biological context of each term.

Option a: Nucleic Acids

Nucleic acids such as DNA and RNA are the building blocks of genetic material, not the structure forming the virus envelope.

Option b: Membrane Structures

Membrane structures are part of the host cell's organelles, such as the cell membrane, which is often used by viruses to form their envelopes.

Option c: Cytoplasm

Cytoplasm is the jelly-like substance within the cell where organelles reside but is not related to the formation of viral envelopes.

Option d: Genome

The genome consists of nucleic acids and defines the genetic material of the virus, but it does not contribute directly to physical structures like the envelope.

Conclusion

Based on the analysis, the option that correctly describes the source of the virus envelope is membrane structures.

Key concepts

host cell membrane

Viruses are clever at finding ways to replicate and spread. One way they do this effectively is by using the host cell membrane to form their own viral envelopes. The viral envelope is an outer layer that wraps around the virus's capsid, providing an extra shield. This envelope is composed of lipids and proteins taken directly from the host's cell membrane. This process involves the virus budding off from the host cell, effectively 'stealing' part of the host membrane to create its envelope.
This strategy helps the virus in several ways:

• It provides a protective outer coating.
• It can help the virus evade the host’s immune system by mimicking the host's cells.
• It aids in the fusion with new host cells for infection.

Understanding the role of the host cell membrane in viral envelope formation helps in studying viral replication and finding ways to disrupt this process to combat viral infections.

virus structure

The structure of a virus is key to its ability to infect and replicate within host cells. A typical virus consists of

• a core of genetic material (either DNA or RNA)
• a protein coat called a capsid that protects this genetic material
• for some viruses, an additional lipid envelope derived from the host cell membrane

These structural components determine how a virus interacts with the host cell and can influence its infectiousness and resistance to treatments. The viral envelope, if present, houses proteins that are critical for binding to host cell receptors, facilitating entry into the host cell.
The structure and composition of viruses vary significantly across different types, affecting their mode of transmission and the strategies needed for prevention and treatment.
Analyzing virus structures allows scientists to develop targeted antiviral therapies and vaccines.

biological membranes

Biological membranes are essential components of cells, providing structure and regulating the movement of substances into and out of the cell. These membranes are made up of a phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates that contribute to its fluidity and function.
Some key functions of biological membranes include:

• Encasing cellular organelles and maintaining cell integrity
• Facilitating communication between cells through receptor proteins
• Regulating the transport of nutrients, waste, and signaling molecules

When viruses infect host cells, they exploit these membranes to their advantage. Enveloped viruses acquire their outer layer from the host's biological membranes during the budding process. This not only provides the virus with camouflage, preventing detection by the immune system, but also equips them with the necessary tools to fuse with other host cells and spread the infection.
Understanding biological membranes is fundamental to comprehending how viruses hijack cellular machinery and provides critical insights into developing antiviral drugs that can block these processes.