Smooth endoplasmic reticulum
(cell biology) (A part of) endoplasmic reticulum that is tubular in form (rather than sheet-like) and lacks ribosomes, and is associated with lipid synthesis, carbohydrate metabolism, calcium concentration, drug detoxification, and attachment of receptors on cell membrane proteins
The endoplasmic reticulum (ER) is an organelle made up of a network of flattened sacs or tubules. The membranes of the ER are connected to the nuclear membrane and run through the cytoplasm. There are two types of ER: (1) the rough endoplasmic reticulum (rER) and (2) the smooth endoplasmic reticulum (sER).
The sER is seen connected to the nuclear envelope, and consists of tubules and vesicles that branch forming a network to increase surface area for the action or storage of key enzymes. Its functions include lipid synthesis, carbohydrate metabolism, calcium concentration, drug detoxification, and attachment of receptors on cell membrane proteins. It contains the enzyme Glucose-6-phosphatase (which converts glucose-6-phosphate to glucose), a step in gluconeogenesis. A specialized form of SER (called sarcoplasmic reticulum) occurs in muscle cells where calcium ions are stored. It is also abundant in hepatocytes to process and detoxify lipophilic drugs. In muscle cells, the smooth endoplasmic reticulum is called sarcoplasmic reticulum.
Abbreviation / Acronym: sER