Answer
The endoplasmic reticulum is an organelle that is closely associated with the nuclear envelope and is made of flattened membrane sacs called cisternae. Its function is to synthesize proteins which are then sent to the golgi aparatus.
Work Step by Step
The endoplasmic reticulum contains 80S ribosomes that actually do the synthesis of proteins throughout the cisternae. The endoplasmic reticulum contains two sections, the rough endoplasmic reticulum (rER) and the smooth endoplasmic reticulum (sER). 80S ribosomes are located within the rER and actually do the synthesis of proteins, it is then transported by vesicles to the golgi apparatus. While the sER contains enzymes on the surface and one of its function is to produce phospholipids to construct the cell membrane.