Monosodium glutamate, or MSG, is a white, crystalline food additive derived from L-glutamic acid, an amino acid found naturally in a wide range of foods like seared beef, egg yolks, tomatoes ...

The amino acid cysteine has a chemically reactive side chain that can form bonds with another cysteine. Amino acids can also be basic, like lysine, or acidic, like glutamic acid. The sequence and ...