20 amino acids: tryptophan, glycine etc.

acid alanine amine amino arginine asparagine aspartic background biology carbon carboxyl chemical chemistry cysteine element etc formula glutamic glutamine glycine health histidine icon isoleucine lab laboratory leucine lysine medicine methionine molecular molecule organic periodic phenylalanine proline research school science serine sign structure symbol test threonine tryptophan tube tyrosine valine vector white