Search results
Results from the WOW.Com Content Network
In plants, all phenylpropanoids are derived from the amino acids phenylalanine and tyrosine. Phenylalanine ammonia-lyase (PAL, a.k.a. phenylalanine/tyrosine ammonia-lyase) is an enzyme that transforms L-phenylalanine and tyrosine into trans-cinnamic acid and p-coumaric acid, respectively.
In plants, the shikimate pathway first leads to the formation of chorismate, which is the precursor of phenylalanine, tyrosine, and tryptophan. These aromatic amino acids are the precursors of many secondary metabolites , all essential to a plant's biological functions, such as the hormones salicylate and auxin .
The enzyme phenylalanine ammonia lyase (EC 4.3.1.24) catalyzes the conversion of L-phenylalanine to ammonia and trans-cinnamic acid.: [1] L -phenylalanine = trans -cinnamate + NH 3 Phenylalanine ammonia lyase (PAL) is the first and committed step in the phenyl propanoid pathway and is therefore involved in the biosynthesis of the polyphenol ...
The pathway starts with two substrates, phosphoenol pyruvate and erythrose-4-phosphate, and ends with chorismate (chrorismic acid), a substrate for the three aromatic amino acids. The fifth enzyme involved is the shikimate kinase , an enzyme that catalyzes the ATP -dependent phosphorylation of shikimate to form shikimate 3-phosphate (shown in ...
In enzymology, chorismate mutase (EC 5.4.99.5) is an enzyme that catalyzes the chemical reaction for the conversion of chorismate to prephenate in the pathway to the production of phenylalanine and tyrosine, also known as the shikimate pathway. Hence, this enzyme has one substrate, chorismate, and one product, prephenate. Chorismate mutase is ...
4-Hydroxyphenylpyruvic acid (4-HPPA) is an intermediate in the metabolism of the amino acid phenylalanine. The aromatic side chain of phenylalanine is hydroxylated by the enzyme phenylalanine hydroxylase to form tyrosine. The conversion from tyrosine to 4-HPPA is in turn catalyzed by tyrosine aminotransferase. [2]
Flavonoids are synthesized by the phenylpropanoid metabolic pathway in which the amino acid phenylalanine is used to produce 4-coumaroyl-CoA. [1] This can be combined with malonyl-CoA to yield the true backbone of flavonoids, a group of compounds called chalcones , which contain two phenyl rings.
Phenylalanine is a precursor for tyrosine, the monoamine neurotransmitters dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline), and the biological pigment melanin. It is encoded by the messenger RNA codons UUU and UUC. Phenylalanine is found naturally in the milk of mammals.