It consists of series of tubules, flattened sacs called cisternae, and membrane-bound spheres called vesicles. There are two types of ER. The rough endoplasmic reticulum (RER) has rows of knobs called ribosomes on its surface. Ribosomes synthesize proteins that, for the most part, are transported out of the cell. read more
The presence of these ribosomes on the outer layer of the RER distinguishes it from smooth endoplasmic reticulum, which is known as the SER. In addition to producing proteins, the RER plays an essential role in many other functions. read more
The rough endoplasmic reticulum (RER) has rows of knobs called ribosomes on its surface. Ribosomes synthesize proteins that, for the most part, are transported out of the cell. The RER is found only in the soma. read more
The rough endoplasmic reticulum is especially prominent in cells such as hepatocytes. The smooth endoplasmic reticulum lacks ribosomes and functions in lipid manufacture and metabolism, the production of steroid hormones, and detoxification. The smooth ER is especially abundant in mammalian liver and gonad cells. read more