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Definition of Lysine
1. Noun. An essential amino acid found in proteins; occurs especially in gelatin and casein. 
Generic synonyms: Essential Amino Acid
Definition of Lysine
1. an amino acid [n -S]
Medical Definition of Lysine
1. 
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1. Noun. An essential amino acid found in proteins; occurs especially in gelatin and casein. 
1. an amino acid [n -S]
1.