synthesis

The endoplasmic reticulum (ER) is indeed involved in protein synthesis, playing a crucial role in the process.
Location and Function: The rough endoplasmic reticulum (RER) is the site where protein synthesis occurs. Ribosomes, which are responsible for protein synthesis, are attached to the membrane of the RER. The RER processes and packages the newly synthesized proteins and transports them in vesicles to the cell membrane or to other organelles such as the Golgi apparatus. Some of these proteins will be utilized by the cell, while others will be sent out into the intercellular space.
Ribosome Attachment sebdermatitis.net The ribosomes that synthesize proteins are directly attached to the ER membrane. These membrane-bound ribosomes coat the surface of the ER, creating regions termed rough endoplasmic reticulum. Regions of ER that lack bound ribosomes are called smooth endoplasmic reticulum, which is involved in the synthesis and storage of lipids.
Role in Protein Folding: The ER also plays a critical role in the correct folding of newly made proteins. Only properly folded proteins are transported from the rough ER to the Golgi apparatus, while unfolded proteins can cause an unfolded protein response as a stress response in the ER.
In summary, the endoplasmic reticulum, particularly the rough endoplasmic reticulum, is intricately involved in protein synthesis, processing, and packaging, playing a vital role in the production and transport of proteins within the cell.