Smooth endoplasmic reticulum is primarily involved with the production of lipids and removing drugs or poisons from the body, according to the British Society for Cell Biology. Rough endoplasmic reticulum is involved in the production, folding, correcting and dispatching of proteins.
The endoplasmic reticulum, often shortened to ER, is a fairly large and highly important organelle found in eukaryotic cells of both plants and animals. It makes up roughly half of an animal cell's total membrane, says BSCB. It is the site of the cell where proteins and lipids are produced and transported to either other parts of the cell, or outside to other cells entirely. The endoplasmic reticulum is divided into two distinct categories, each with their own function and distinct texture: smooth ER and rough ER.
Rough ER is so called due to its texture, as it is covered with ribosomes that give it a bumpy appearance, according to BSCB. These ribosomes are what is used to assemble amino acids into protein units, a process called "translation," which are then transported into the rough ER for further processing. The end result are proteins that can be used in the cell or throughout the body; for example, cells of the pancreas and digestive tracts produce large quantities of proteins which are used as digestive enzymes.
Smooth ER lacks the ribosomes found on its counterpart, and is devoted almost entirely to the production, and occasionally metabolism, of lipids. While the production of lipids is used in the metabolising of carbohydrates, the metabolising of lipids allows the smooth ER to serve the function of detoxifying substances that enter the body. In cells that serve this function, such as the liver, organic chemicals are converted to water-soluble products, which are easier to transport out of the body, says BSCB.