Question

In describing the release of mature enveloped viruses from host cells, the term exocytosis and ________________ are interchangeable.

Answer 1

Exocytosis and budding are interchangeable terms that describe how enveloped viruses exit a host cell. Budding involves the virions leaving the cell individually, taking a piece of the cell's membrane, whereas non-enveloped viruses cause the cell to lyse or undergo apoptosis to release all virions simultaneously.

Step-by-step explanation:

In describing the release of mature enveloped viruses from host cells, the term exocytosis and budding are interchangeable.

During the last stage of viral replication, new virions exit the host cell to infect adjacent cells. This process—known as egress—can occur in two main ways. Enveloped viruses often leave the host cell through budding. In this process, virions are enveloped in a portion of the cell's plasma membrane as they exit individually. This method of viral exit is less destructive to the host cell compared to the abrupt release that occurs when the cell is lysed or undergoes apoptosis.

On the other hand, for non-enveloped viruses, such as rhinoviruses, the approach to exiting the host cell is different. These viruses accumulate inside the cell until they receive a signal to induce cell lysis or apoptosis, at which point all the virions are released collectively, often resulting in the destruction of the host cell.

Answer 2

In virology, the term budding is used interchangeably with exocytosis to describe the release of mature enveloped viruses from the host cell, which involves the virus acquiring an envelope from the host cell's membrane.

Step-by-step explanation:

In the context of viral replication, the release of mature enveloped viruses from host cells through exocytosis is often called budding.

This process allows the virus to exit the cell while wrapping itself in a portion of the host cell's plasma membrane, thus acquiring its envelope. Unlike exocytosis, which also involves vesicles fusing with the plasma membrane to release material, the budding process is specific to certain animal viruses and is part of their replication cycle, ultimately leading to the release of new virions.

During budding, the cell does not necessarily undergo immediate death (or cell necrosis), but the damage incurred by the virus infecting the host cell may impair its normal functions. Egress, or the final step in the viral life cycle, encompasses both the budding process for enveloped viruses and the burst release of virions for non-enveloped viruses that occurs when a host cell undergoes lysis or apoptosis.