What is the primary function of the smooth endoplasmic reticulum?

The primary function of the smooth endoplasmic reticulum (SER) is lipid synthesis. Unlike the rough endoplasmic reticulum, which is studded with ribosomes and primarily involved in the synthesis of proteins, the smooth endoplasmic reticulum lacks these ribosomes and is primarily focused on the production of lipids. This includes fatty acids, phospholipids, and steroids, which are critical components of cell membranes and serve various roles in cellular functions. Additionally, the smooth endoplasmic reticulum is involved in the metabolism of carbohydrates and the detoxification of drugs and poisons, further supporting its role in lipid metabolism and cellular homeostasis.