Pepsin

Part of speech: noun

Pronunciation: /ˈpɛpsɪn/

Definitions

1. A type of enzyme secreted in the stomach that facilitates the degradation of proteins into smaller components
2. An enzyme responsible for the breakdown of protein molecules into peptides during digestion
3. A digestive enzyme produced in the stomach that catalyzes the conversion of proteins into smaller peptides for absorption

Etymology: Pepsin was named in 1836 by the German physiologist Theodor Schwann, who isolated it from the stomach lining. Its name was built from the Ancient Greek "pépsis", meaning "digestion" (from "péptein", "to cook or digest"), with the chemical suffix "-in" added, the standard German ending for substances of this kind. The word is therefore a deliberate scientific coinage rather than an old term. Ancient Greek physicians had no concept of a stomach enzyme, so the Greek root was borrowed to name a substance that only became identifiable in the nineteenth century, and the suffix marks it as a purified protein-digesting agent.