enzyme n.

word-forming element meaning "near, at, in, on, within," from Greek en "in," cognate with Latin in (from PIE root *en "in"), and thus with en- (1). Typically assimilated to em- before -p-, -b-, -m-, -l-, and -r-.

branch of chemistry which deals with wine-making and brewing, 1868, from Greek zymo-, combining form of zymē "a leaven" (from PIE root *yeue-; see juice) + -ourgia "a working," from ergon "work" (from PIE root *werg- "to do").

The last word in many standard English dictionaries (and this one); but Century Dictionary ends with Zyxomma ("A genus of Indian dragon-flies") and in the OED [2nd ed.] the last word is zyxt, an obsolete Kentish form of the second person singular of see (v.).

At the dictionary's letter A

Mr. Brandt is young and gay

But when at last he reaches zed

He's in his wheelchair, nearly dead

[Einar Haugen]

type of immune-system enzyme found in tears, saliva, egg-whites, etc., 1922, named by its discoverer, Alexander Fleming (six years before he discovered penicillin), who coined it from lyso- "loosening, dissolving" + suffix from enzyme. So called because it attack bacteria cell walls.