精氨酸

argnine (Arg), an essential amino acid

essence / extract / vitality / energy / semen / sperm / mythical goblin spirit / highly perfected / elite / the pick of sth / proficient (refined ability) / extremely (fine) / selected rice (archaic)

sour / tart / sick at heart / grieved / sore / aching / pedantic / impractical / to make sarcastic remarks about sb / an acid

ammonia