This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Structure and function of protein, Subject name: Biochemistry
All are essential amino acids except 
Select and explain. 
A. Glycine, B. Valine, C. Isoleucine, D. Tryptophan
A: Glycine
Answer: A: Glycine 
Explanation: Essential or indispensable amino acids: The amino acids which cannot be synthesized by the body and, therefore, need to be supplied through the diet are called essential amino acids. They are required for proper Growth and maintenance of the individual. The ten amino acids listed below are essential for humans (and also rats): Arginine, Valine, Histidine, isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan. the code A.U HILL, MP., T. T. (first letter of each amino acid) may be memorized to recall essential amino acids. Other useful codes are H. VITTAL, LMP; PH. VILMA, TT, PW TIM HALL and MATTVILPhLy.IRef: Biochemistry, U. Satyanarayana, 3rd edition, page no: 47