Tyrosine: Tyrosine is an aromatic amino acid that can absorb light. It forms a form of phenylalanine by a reaction catalyzed by phenylalanine hydroxylase. Phenylalanine is an essential amino acid, but tyrosine is not, if the diet contains a sufficient amount of phenylalanine. The reaction is not reversible, so tyrosine can not replace the need for phenylalanine. Tyrosine should avoid action, because if tyrosine is given, it is necessary to reduce the phenylalanine in the body. Both amino acids are ketogenic and at the same time glucogenic. Both have an enormous metabolic role in the body and are metabolized through common routes. The catabolism of tyrosine leads to the formation of acetoacetic acid, phenol, tyramine, adrenaline (adrenaline), no adrenaline (no adrenaline), thyroid hormones and melanin in individual reactions.
Tyrosine is essential for protein synthesis and serves as a precursor to thyroxine, melanin and catecholamine.
The amino acid tyrosine, found in chicken and tuna, improves the chemical properties of the brain, improving motivation and reaction time. The defective metabolic anomalies generated from tyrosine lead to tyrosinosis, alcaptonuria (okkrozu) and albinism; which are described below.
An excess of tyrosine, when serum tyrosine levels increase to 6-12 mg / dL, as in methionine, a condition called tyrosine affects the activity of various enzymes and transport systems. In acute thirst in babies, diarrhea, vomiting with cabbage are like an odor and can not flower. In the absence of treatment, death from liver failure occurs after 6 to 8 months. In chronic thyroid, the symptoms are similar, but milder, and death, at 10 years. Treatment consists of a diet low in phenylalanine and tyrosine; Also several times low even in methionine.
Another metabolic defect is tyrosinosis.
Type II, where the level of tyrosine in serum at a dose of 4-5 mg / dL, is hepatic with damage to the eyes and skin and some mental retardation. It is the only amino acid whose urine concentration increases, while renal clearance and l tyrosine health benefits reuptake are within normal limits. Another disease, neonatal tyrosis, in which levels of tyrosine and phenylalanine increase in the blood, increases the level of tyrosine in the urine. The treatment consists of a low protein diet.
Melanins are polymers of tyrosine catabolites catalyzed by tyrosine hydroxylase.
Albinos l tyrosine side effect hydroxylase: as a negative deficiency of all visual pigments and hair follicles, it is not possible to convert the added tyrosine into a pigment; As a positive, there are some visual pigments and hair follicles that convert tyrosine to eumelanin in vitro.
Tyrosine forms adrenaline and not adrenaline when it becomes cells of nervous origin with the help of enzymes contained in the brain of the adrenal glands. The limitation of the speed of the enzyme in the process of catecholamine biosynthesis is tyrosine hydroxylase. Tyrosine is also a precursor to thyroid hormones. Free tyrosine can be iodized by the reactionary organization. Ascorbic acid (vitamin C) is necessary for the degradation of tyrosine, as well as in the synthesis of adrenaline from tyrosine.