(n)an essential amino acid found in proteins and needed for growth of children and for protein metabolism in children and adults; abundant in milk and eggs; it is normally converted to tyrosine in the human body
n. [ Aldehyde + the ending -ine. The -n- is a euphonic insertion. ] (Chem.) one of the natural amino acids found combined in the proteins of most living tissues. It can be isolated as a white crystalline base, C3H7NO2. The natural form is the L-configuration. [ 1913 Webster +PJC ]