What Is the Function of the Rough ER?

The rough endoplasmic reticulum (ER) performs several crucial functions, such as manufacturing lysosomal enzymes, manufacturing secreted proteins, integrating proteins in the cell membrane and facilitating glycosylation. The rough ER is an ancillary component of the broader endoplasmic reticulum, which contains a smooth surface in addition to the rough edges of the ER. Despite sharing a location, the smooth and rough ER perform different functions to facilitate basic operations within cells.

The difference between the rough ER and smooth ER starts at the surface level. The surface of the rough ER is dotted with protein-manufacturing ribosomes, which give it a studded and uneven appearance. According to Georgia State University, the rough ER is identified by the presence of ribosomes because the smooth ER does not attract or retain these cell components. The rough ER contains a key binding site, called the translocon, which attracts and captures ribosomes. Ribosomes only attach to the ER surface for brief periods of time; however, they stay long enough to complete the formation of a protein-nucleic acid. In addition to serving as a housing spot for ribosomes, rough ERs produce several enzymes and proteins, which are then secreted into the surrounding cell. Rough ERs also generate protective pockets, which transport protein to the Golgi complex.