Tyrosine facts

• Tyrosine is a conditionally essential amino acid
• Tyrosine functions as a building block of protein in the body
• Tyrosine is required for phenylalanine metabolism

While tyrosine is not an essential amino acid most of the time (essential amino acids are required in the diet as the body cannot manufacture them), there are certain special circumstances which makes it conditionally essential; this means glycine becomes an essential amino acid under special conditions, especially when intake of the essential amino acid phenylalanine are very low.

Tyrosine, just like all the other amino acids, is one of the building blocks of all proteins in the body, which not only include muscles, but also all the other proteins required for normal function of the body.

Tyrosine is needed for the body to properly metabolise and use the essential amino acid phenylalanine> and this is important for people who have the genetic disorder phenylketonuria. Studies show that tyrosine has important implications in the development of phenylketonuria in the unborn foetus. Studies have suggested that part of the mental retardation that occurs with phenylketonuria may be due to not just phenylalanine excess, but also tyrosine deficiency. This is an example of how tyrosine is a conditionally essential amino acid due to a genetic uniqueness in metabolism.