Diacylglycerol

Part of speech: noun

Definitions

1. A type of lipid molecule consisting of two fatty acid chains attached to a glycerol backbone
2. A structural component of cell membranes, serving both as an energy source and a signaling molecule in various biochemical pathways
3. An important intermediary in lipid metabolism, playing a key role in energy storage and cell signaling processes

Etymology: Diacylglycerol is a technical coinage, built in a fairly mechanical way from two parts. The first, "di-", comes from the Greek "dis", meaning "two" or "twice", and reached English through Latin and scientific usage as a standard prefix for "two of something." The second part, "acylglycerol," names a family of fat molecules in which a glycerol backbone, a three-carbon alcohol, has been joined to one or more acyl groups, the fatty-acid residues that give fats their character. Put together, the name describes exactly what the molecule is: a glycerol backbone carrying two acyl groups, with the third position of the glycerol left free. Chemists needed names like this to distinguish the monoacyl, diacyl and triacyl forms, which differ in structure and in how the body handles them. Because the prefix is so regular, the word reads transparently to anyone who knows the pattern, and its meaning can be worked out from its parts without any special history behind it.

Synonyms: DAG, diglyceride, glycerol diester