Glycans

Part of speech: noun

Definitions

1. A class of carbohydrates composed of sugar molecules linked together that play essential roles in cellular recognition and signaling
2. Complex sugar chains important in biological processes, including cell communication and immune responses
3. Polysaccharide molecules formed from monosaccharide units that are vital for various physiological functions and structural purposes in organisms

Etymology: "Glycans" is simply the plural of "glycan," a noun for a polysaccharide built from monosaccharide units. The singular is the older formation, so the plural is the form you will meet most often in biochemistry texts discussing many such molecules at once. The word is built from two Greek-derived elements: "glyk-", from Greek "glykys," meaning "sweet," which chemists use for sugars, and the suffix "-an," a standard chemical ending for polysaccharides, as in "cellulose" and "starch" family names. The pairing makes sense once you see the logic. Sugars were named for their taste, so "glyk-" points to sweetness, while the "-an" ending marks a long chain of linked sugar units rather than a single sugar. A glycan is therefore a sweet-based compound in the sense of being made of sugars, even though most glycans, such as the cellulose in plant cell walls, taste of nothing at all.

Synonyms: carbohydrates, polysaccharides, sugars, oligosaccharides