Lysine, Tryptophan or Glutamine for Example

This page is the CodyCross answer for the clue below from Mesopotamia, Group 973, Puzzle 4 (Cereal Crops).

Question is: Lysine, Tryptophan or Glutamine for Example

and the answer is: AMINOACID

Word Meaning:

AMINO ACID — (biochemistry) Any organic compound containing both an amino and a carboxylic acid functional group.

Definitions from Wiktionary.