色氨酸 Traditional form: 色氨酸 Pinyin (reading): sè'ānsuān Definitions: tryptophan (Trp), an essential amino acid Characters: 色 - color, tint, hue, shade; beauty, form; sex 氨 - ammonia 酸 - tart, sour; spoiled; acid Traditional characters: 色 - color, tint, hue, shade; beauty, form; sex 氨 - ammonia 酸 - tart, sour; spoiled; acid