smooth endoplasmic reticulum

    In eukaryotic cells, the smooth ER is a major site where membrane lipids are synthesized (Cooper). Membrane lipids must be synthesized on the cytosolic side of the ER membrane, or outside of the ER membrane (Cooper). After the lipids are synthesized they follow a similar pathway to proteins where vesicles transport the lipids to their final destinations. The smooth ER more specifically synthesizes three important membrane lipids: ceramide, cholesterol, and glycerol phospholipids (Cooper). Ceramide undergoes further processing in the Golgi to become sphingomyelin. Therefore the smooth ER produces a variety of lipids that either act as precursors that require more processing or are final products (Cooper).