This collection of membranes is called the endoplasmic reticulum , or ER . The ER stretches from the nuclear membrane to the plasma membrane. It serves as a pathway through the cytoplasm, as a support structure for the attachment of other organelles, and as a workstation for the ribosomes. The rough ER has ribosomes attached to it and provides a surface along which the process of protein assembly can occur. The smooth ER does not have ribosomes and is much more tubular in appearance.
Ribosomes manufacture proteins.
The Ribosomes Ribosomes, the workers that build proteins, are manufactured by the nucleolus. Ribosomes attach to the rough ER . Now let's take a look at how final processing occurs. Inc. All rights reserved.