What is the structure composed of a viral capsid with an envelope known as?

The structure composed of a viral capsid along with an envelope is known as a nucleocapsid. This term specifically refers to the combination of the viral genome—contained within the capsid—and any associated proteins that are crucial for the virus’s structure and function. The capsid itself provides protection for the viral genetic material and is essential for the virus’s ability to infect host cells.

The envelope is a lipid bilayer that surrounds the capsid, derived from the host cell's membrane during the budding process. While the envelope is integral for certain viral entry mechanisms and immune evasion, the complete assembly that includes both the capsid and the envelope is termed the nucleocapsid, highlighting the importance of these components in the virus's life cycle. This distinction is critical in understanding virus structure and pathogenesis.