All of the following are essential amino acids include all, EXCEPT:

The essential amino acids are leucine, isoleucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, and histidine. Protein is required for growth and for maintenance of body structure and function. The true requirement is for nine essential amino acids plus additional nitrogen for protein synthesis. Adequate protein must be consumed each day to replace essential amino acids lost through protein turnover. Allowing for differences in protein quality and utilization and for individual variability, the RDA (USA) for protein is 56 g/d for men and 45 g/d for women. Ref: Baron R.B. (2013). Chapter 29. Nutritional Disorders. In M.A. Papadakis, S.J. McPhee, M.W. Rabow (Eds), CURRENT Medical Diagnosis & Treatment 2013.