Answer:
Endoplasmic reticulum
Step-by-step explanation:
The endoplasmic reticulum is part of the endomembrane system inside almost all eukaryotic cells.
The membrane is continuous with the nuclear membrane. The endoplasmic reticulum is very important for modifying proteins and transporting them in vesicles to the Golgi body for further processing and transport to their final destinations.
The endoplasmic reticulum can be rough (have ribosomes attached) or smooth (lack ribosomes).