What is the role of the endoplasmic reticulum in protein synthesis?
Ribosomes are the site of protein synthesis, and can occur freely in the cytoplasm though more commonly on the outer surface of rough endoplasmic reticulum. The endoplasmic reticulum presents a large surface area on which these ribosomes can be situated, therefore allowing protein synthesis to occur on a large scale. Rough endoplasmic reticulum is particularly abundant in growing cells which demand a high turnover of materials in its growth. Rough ER is responsible for transporting the newly synthesised proteins to the Golgi apparatus. The smooth endoplasmic reticulum (SER) has no such bound ribosomes and is not involved in protein synthesis. However, the SER is involved in: cholesterol metabolism, membrane synthesis, detoxification, Ca++ storage along with other cellular processes.
