The Rough Endoplasmic Reticulum

The reason that the rough Endoplasmic Reticulum is called the rough Endoplasmic Reticulum is because of the ribosomes that are held onto the Endoplasmic Reticulum by hydrophobic proteins. The rough Endoplasmic Reticulum secretes proteins made by ribosomes. In pancreas cells, it gives off the protein insulin into the blood stream. A polypeptide is threaded into the rough Endoplasmic Reticulum which then goes into the cisternal area of the ER. Most proteins secreted would be the glycoprotein, a protein, which is covalent bonded to a carbohydrate, then which is wrapped in bubbles and secreted out of the rough Endoplasmic Reticulum.

The secreted proteins leave the rough Endoplasmic Reticulum by means of a special region called the transport vesicles of the RER. Thus, the bubbles made by the RER, adds phosolipids and membranes to wherever, in the cell, they are needed.