amino acid

Amino acids are molecules that combine to form proteins. 20 amino acids make up the proteins of the human body. Of these, 8 are essential (our body cannot synthesise them, they must be supplied by the diet): isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine.
Arginine and histidine are semi-indispensable. In fact, only infants need to take them from their food.
Cysteine, glycine and tyrosine may be indispensable for certain populations