Amino Acid Metabolism

Described for its complexity brought about by the large number involved, amino acid metabolism can actually be split into 20 protein block- builders that are significant for biosynthesis.

Functioning as precursors for the manufacturing of a lot of molecules that send signals, they are also unique from the peculiar ones that are utilized for a variety of intermediary pathways and activated one- carbon unit for the aromatic production.



Prior to the metabolic fate of the carbon atoms, they can actually be detected to all the chief intermediates due to the close interaction of amino acid metabolism with the citric acid cycle and glycolysis. Those intermediates comprises of carbons from pyruvate, acetyl- CoA, acetoacetyl- CoA, a- ketoglutarate, succinyl- CoA, fumarate, malate and oxaloacetate.

It is actually separated into several pathways according to the diverse length of carbon structures engaged. They are referred to as C3, C4 and C5 families of protein block- builders that generate common end products during catabolism. C3 includes alanine, serine and cysteine which are all corrupted to pyruvate. C4 have aspartate and asparagoine that are tainted to oxaloacetate that are closely linked to glutamate. C5 comprises of glutamine, proline, arginine and hitidine that are all deaminated to alpha- ketoglutarate.

Aromatic Engineers

Phenylalanine, tyrosine trytophan are the three pungent amino acid metabolism. They all contain benzene ring which are hydroxylated. The relationships they have for each other actually cause the acceleration to an intricate nutritional liberty. The disorder in the otherhand like the impairment of fabricating tyrosine from phenylalanine makes the previous one of the essentials needed very much in the body. The lack of biosynthetic pathways in human beings is the reason why there are plenty of sicknesses associated with malnutrition.


First converted to tyrosine by the accumulation of a hydroxyl unit, phenylalanine is a reaction catalyzed by phenylalanine hydroxylase. This is actually a liver specific enzyme which belongs to the group of monooxygenases. Such requires molecular oxygen, NADPH and coenzyme tetra- hydrobiopterine. Rememeber that hydroxylation of the benzene ring is utilized to destabilize in the preparation of the ring formation for breakup.


An amino acid metabolism that is a liver resident process, Tyrosine starts out with alteration of its amino group to alpha- ketoglutarate by a certain method used. This is similar to both that accepts transminases and less substrate which acts on aspartate. It is an enzyme isoform that is obtained from aromatic amino acid transaminase by restrained proteolysis.


With the degradation in human that yields to precursors for glucose synthesis, tryptophan is the first step that is catalyzed and controlled by cortisol. It stimulates its own degradation by allosterically activating tryptophan oxygenase. The product of the said reaction is L- formylkynurenine that is further degraded by kynurenine formidase.