Biochemistry General 42f8ee19 An essential amino acid in man is A Aspartate B Tyrosine C Methionine D Serine High-Yield Explanation Isoleucine, Leucine, Threonine, Lysine, Methionine, Phenylalanine, Tryptophan, and Valine are essential amino acids. Reference: Vasudevan 7th ed, pg 27