One of the nonessential
The simplest amino acid (NH 2 CH 2 COOH), it occurs in many proteins ; especially rich sources are silk fibroin and gelatin. It has a sweet taste and is used to reduce the bitter flavour of {{link=saccharin">saccharin . Other uses are in organic synthesis and biochemical research, as a nutrient and feed additive, and to retard rancidity in animal and vegetable fats.