Final answer:
The plasma membrane of a cell is similar to the envelope of a virus. Both are composed of a lipid bilayer and proteins. Viruses use part of the host cell's plasma membrane to form their envelope during budding.
Step-by-step explanation:
The organelle of a cell that functions similarly to the envelope of a virus is the plasma membrane of the cell. Just like the viral envelope, the plasma membrane is composed of a lipid bilayer with embedded proteins that can function in communication and transport. When enveloped viruses, such as influenza virus or HIV, exit a host cell, they bud off from the cell, incorporating part of the plasma membrane to form their protective envelope. This incorporates host cell lipids and membrane proteins along with virus-encoded proteins like glycoproteins, which help the virus attach and enter other host cells.
Within a eukaryotic cell, organelles like the endoplasmic reticulum (ER) and Golgi apparatus are also involved in the synthesis and packaging of proteins and membranes, showing the integral role of membranes in both cellular and viral life cycles. The endomembrane system within a cell manages the production and export of cellular products, mirroring the way a virus uses host cell membranes for the assembly and release of new virions.