Final answer:
The outer membrane of the nuclear envelope is continuous with the rough endoplasmic reticulum, which is part of the endomembrane system involved in modifying and transporting proteins and lipids in the cell.
Step-by-step explanation:
The outer membrane of the nuclear envelope is continuous with the RER (rough endoplasmic reticulum). This continuity allows the lumen of the RER to be connected with the space between the two membranes of the nuclear envelope. The RER, characterized by the presence of bound ribosomes on its surface, is critical in protein synthesis for proteins that are either secreted from the cell, incorporated into the cell's plasma membrane, or sent to an organelle called the lysosome. The endomembrane system includes various cellular components such as the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and vesicles, as well as the plasma membrane, which all work together to modify, package, tag, and transport proteins and lipids that form the cell's membranes.