Glycopeptide

Part of speech: noun

Definitions

1. A molecule made of a carbohydrate chain chemically bonded to a short chain of amino acids, found in many biological structures
2. A compound in which a sugar unit is linked to a peptide, forming a hybrid molecule common in cell surfaces and antibiotics
3. Any organic molecule combining a carbohydrate component with a peptide backbone, such as many glycoproteins and certain antibiotics

Etymology: Glycopeptides are built from two parts whose names both trace back to ancient Greek roots, though the pieces arrived in English by different routes. "Glyco-" comes from the Greek "glukus," meaning sweet, and it is the element that signals a sugar component. "Peptide" is the more interesting half. The Greek verb "pessō" meant to cook or digest, and the noun "peptón," meaning digested or cooked, gave rise to "pepton," a term coined in nineteenth-century German for the products of protein digestion. English borrowed "peptone" from that German word, and chemists later built "peptide" on it, using the Latin-derived suffix "-ide" that marks a chemical compound. A glycopeptide, then, is a peptide, a chain of amino acids, with a sugar attached. The compound name is a modern scientific coinage, so the Greek elements were assembled by chemists rather than used by ancient writers.