NationMaster - Encyclopedia: Phenylalanine

Phenyl alanine is an α-amino acid with the formula HO₂CCH(NH₂)CH₂C₆H₅. This essential amino acid is classified as nonpolar because of the hydrophobic nature of the benzyl side chain. The codons for L-phenylalanine are UUU and UUC. It is a white, powdery solid. L-Phenylalanine (LPA) is an electrically-neutral amino acid, one of the twenty common amino acids used to biochemically form proteins, coded for by DNA. IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... This article or section does not cite any references or sources. ... The molecular mass (abbreviated Mr) of a substance, formerly also called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ... In physics, density is mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: Ï (rho) is the density of the substance, measured in kgÂ·m-3 m is the mass of the substance, measured in kg V is... The isoelectric point (pI) is the pH at which a molecule or surface carries no net electrical charge. ... The acid dissociation constant (Ka), also known as the acidity constant or the acid-ionization constant, is a specific equilibrium constant for the reaction of an acid with its conjugate base in aqueous solution [1]. // When an acid dissolves in water, it partly dissociates forming hydronium ions and its conjugate... PubChem is a database of chemical molecules. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ... Image File history File links Download high resolution version (1551x1581, 28 KB) Licensing File links The following pages link to this file: Amino acid Phenylalanine User:Benjah-bmm27/Gallery ... Image File history File links Download high resolution version (687x722, 26 KB) Licensing File links The following pages link to this file: Phenylalanine User:Benjah-bmm27/Gallery ... Phenylalanine is one of the standard amino acids. ... This article or section does not cite any references or sources. ... An essential amino acid or indispensable amino acid, is an amino acid that cannot be synthesized de novo by the organism (usually referring to humans), and therefore must be supplied in the diet. ... In chemistry, a nonpolar compound is one that does not have concentrations of positive or negative electric charge. ... In chemistry, hydrophobic or lipophilic species, or hydrophobes, tend to be electrically neutral and nonpolar, and thus prefer other neutral and nonpolar solvents or molecular environments. ... Benzyl is the Organic chemistry term for the radical C6H5CH2-. It is obtained by removing a proton from benzene. ... RNA codons. ... For other uses, see Solid (disambiguation). ... Phenylalanine is one of the standard amino acids. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... The structure of part of a DNA double helix Deoxyribonucleic acid, or DNA, is a nucleic acid molecule that contains the genetic instructions used in the development and functioning of all known living organisms. ...

Biosynthesis

Phenylalanine cannot be made by animals, which have to obtain it from their diet. It is produced by plants and most microorganisms from prephenate, an intermediate on the shikimate pathway.^[1] Prephenic acid, more commonly known by its anionic form prephenate, is an intermediate in the biosynthesis of the aromatic amino acids phenylalanine and tyrosine. ... Shikimic acid, more commonly known as its anionic form shikimate, is an important biochemical intermediate in plants and microorganisms. ...

Prephenate is decarboxylated with loss of the hydroxyl group to give phenylpyruvate. This species is transaminated using glutamate as the nitrogen source to give phenylalanine and α-ketoglutarate. Image File history File links Download high resolution version (1557x433, 13 KB) Description: Biosynthesis of phenylalanine. ... A Decarboxylation is any chemical reaction in which a carboxyl group (-COOH) is split off from a compound as carbon dioxide (CO2). ... // Hydroxyl group The term hydroxyl group is used to describe the functional group -OH when it is a substituent in an organic compound. ... Transamination is the reaction between an amino acid and an alpha-keto acid. ... Glutamic acid (Glu, E), is the protonated form of glutamate (the anion). ... Ketoglutaric acid is used for either of two crystalline keto derivatives C5H6O5 of glutaric acid. ...

Other biological roles

L-phenylalanine can also be converted into L-tyrosine, another one of the DNA-encoded amino acids. L-tyrosine in turn is converted into L-DOPA, which is further converted into dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline) (the latter three are known as the catecholamines). Tyrosine (from the Greek tyros, meaning cheese, as it was first discovered in 1846 by German chemist Justus von Liebig in cheese[1][2]), 4-hydroxyphenylalanine, or 2-amino-3(4-hydroxyphenyl)-propanoic acid, is one of the 20 amino acids that are used by cells to synthesize proteins. ... // Therapeutic use L-DOPA is used to replace dopamine lost in Parkinsons disease because dopamine itself cannot cross the blood-brain barrierwhere its precursor can. ... Dopamine is a phenethylamine naturally produced by the human body. ... Norepinephrine (INN)(abbr. ... Adrenaline redirects here. ... Catecholamines are chemical compounds derived from the amino acid tyrosine that act as hormones or neurotransmitters. ...

Phenylalanine uses the same active transport channel as tryptophan to cross the blood-brain barrier, and, in large quantities, interferes with the production of serotonin. Tryptophan is an essential amino acid involved in human nutrition. ... The blood-brain barrier (BBB) is a membranic structure that acts primarily to protect the brain from chemicals in the blood, while still allowing essential metabolic function. ... Serotonin (pronounced ) (5-hydroxytryptamine, or 5-HT) is a monoamine neurotransmitter synthesized in serotonergic neurons in the central nervous system (CNS) and enterochromaffin cells in the gastrointestinal tract of animals including humans. ...

Lignin is derived from phenylalanine and from tyrosine. Phenylalanine is converted to cinnamic acid by the enzyme phenylalanine ammonia lyase.^[1] Lignin (sometimes lignen) is a chemical compound (complex, highly cross-linked aromatic polymer) that is most commonly derived from wood and is an integral part of the cell walls of plants, especially in tracheids, xylem fibres and sclereids. ... Tyrosine (from the Greek tyros, meaning cheese, as it was first discovered in 1846 by German chemist Justus von Liebig in cheese[1][2]), 4-hydroxyphenylalanine, or 2-amino-3(4-hydroxyphenyl)-propanoic acid, is one of the 20 amino acids that are used by cells to synthesize proteins. ... Cinnamic acid has the formula C6H5CHCHCOOH and is an odorless white crystalline acid, which is slightly soluble in water. ...

Phenylketonuria

The genetic disorder phenylketonuria (PKU) is the inability to metabolize phenylalanine. Individuals with this disorder are known as "phenylketonurics" and must abstain from consumption of phenylalanine. This dietary restriction also applies to pregnant women with hyperphenylalanine (high levels of phenylalanine in blood) because they do not properly metabolize the amino acid phenylalanine. Phenylalanine is present in many sugarless gums, Monster Munch crisps, sugarless soft drinks (such as Diet sodas), some forms of Lipton Tea, Icebreakers Mints, Clear Splash flavored water, and a number of other food products, all of which must be labeled: "Phenylketonurics: Contains phenylalanine." (In the UK, foods containing aspartame must carry ingredients panels that refer to the presence of 'aspartame or E951', says the country's Food Standards Agency [1] - and they 'must be labelled with a warning "Contains a source of phenylalanine".' This is usually the last line of the ingredients. 'Products containing sweeteners such as aspartame must show the statement "with sweetener(s)",' the agency adds. This should be 'close to the main product name'. And 'foods that contain both sugar and sweetener must carry the statement "with sugar and sweetener(s)". In addition, foods that contain aspartame must be labelled with a warning 'contains a source of phenylalanine'. This warning is specifically to aid individuals who suffer from PKU, so that they can avoid such foods.') Image File history File links This is a lossless scalable vector image. ... PhenylKetonUria (PKU) is an autosomal recessive genetic disorder characterized by a deficiency in the enzyme phenylalanine hydroxylase (PAH). ... PhenylKetonUria (PKU) is an autosomal recessive genetic disorder characterized by a deficiency in the enzyme phenylalanine hydroxylase (PAH). ... Two packets of Flamin Hot flavour Monster Munch. ...

Phenylalanine itself is not present in the food. Rather, the artificial sweetener sold under the names "Equal" and "NutraSweet" contain aspartame, an ester that is hydrolyzed in the body to give phenylalanine, aspartic acid, and methanol (wood alcohol). Thus, aspartame is problematic for persons with PKU. The amounts produced by aspartame pose a risk however, as far larger quantities of the amino acid would be obtained through consuming normal protein^{[citation needed]}. Interestingly, the macaque genome was recently sequenced and it was found that macaques naturally have a mutation that is found in humans who have PKU.[2] Aspartame (or APM) (IPA: ) is the name for an artificial, non-saccharide sweetener, aspartyl-phenylalanine-1-methyl ester; i. ... Hydrolysis is a chemical reaction or process in which a chemical compound reacts with water. ... Aspartic acid (Asp, D), also known as aspartate, the name of its anion, is one of the 20 natural proteinogenic amino acids which are the building blocks of proteins. ... Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naptha or wood spirits, is a chemical compound with chemical formula CH3OH. It is the simplest alcohol, and is a light, volatile, colourless, flammable, poisonous liquid with a distinctive odor that is somewhat milder and sweeter than ethanol (ethyl alcohol). ... Type Species Simia inuus Linnaeus, 1758 = Simia sylvanus Linnaeus, 1758 Species See text. ...

D- and DL-phenylalanine

D-phenylalanine (DPA) either as a single enantiomer or as a component of the racemic mixture is available through conventional organic synthesis. It does not participate in protein biosynthesis although it is found in proteins, in small amounts, particularly aged proteins and food proteins that have been processed. The biological functions of D-amino acids remain unclear. Some D-amino acids, such as D-phenylalanine, may have pharmacologic activity. Organic synthesis is the construction of organic molecules via chemical processes. ...

DL-Phenylalanine is marketed as a nutritional supplement for its putative analgesic and antidepressant activities. The putative analgesic activity of DL-phenylalanine may be explained by the possible blockage by D-phenylalanine of enkephalin degradation by the enzyme carboxypeptidase A. The mechanism of DL-phenylalanine's putative antidepressant activity may be accounted for by the precursor role of L-phenylalanine in the synthesis of the neurotransmitters norepinephrine and dopamine. Elevated brain norepinephrine and dopamine levels are thought to be associated with antidepressant effects.

D-phenylalanine is absorbed from the small intestine, following ingestion, and transported to the liver via the portal circulation. A fraction of D-phenylalanine appears to be converted to L-phenylalanine. D-phenylalanine is distributed to the various tissues of the body via the systemic circulation. D-phenylalanine appears to cross the blood-brain barrier with less efficiency than L-phenylalanine. A fraction of an ingested dose of D-phenylalanine is excreted in the urine. Circulation of blood to the liver from the small intestine via the portal vein. ... Systemic circulation is the portion of the cardiovascular system which carries oxygenated blood away from the heart, to the body, and returns deoxygenated blood back to the heart. ... The blood-brain barrier (BBB) is a membranic structure that acts primarily to protect the brain from chemicals in the blood, while still allowing essential metabolic function. ... This article or section is in need of attention from an expert on the subject. ...

History

The genetic codon for phenylalanine was the first to be discovered. Marshall W. Nirenberg discovered that insertion of m-RNA made up of multiple uracil repeats into E. coli, the bacterium produced a new protein, made up solely of repeated phenylalanine amino acids. RNA codons. ... Marshall Nirenberg won a Nobel Prize in 1968 Marshall Warren Nirenberg (born April 10, 1927) was a U.S. biochemist and geneticist. ... Ribonucleic acid or RNA is a nucleic acid polymer consisting of nucleotide monomers that plays several important roles in the processes that translate genetic information from deoxyribonucleic acid (DNA) into protein products; RNA acts as a messenger between DNA and the protein synthesis complexes known as ribosomes, forms vital portions... Uracil is a pyrimidine which is common and naturally occurring. ...

References

External links

Categories: Cleanup from August 2007 | Wikipedia articles needing clarification | All articles with unsourced statements | Articles with unsourced statements since August 2007 | Proteinogenic amino acids | Glucogenic amino acids | Ketogenic amino acids | Aromatic amino acids | Essential amino acids Biochemistry is the study of the chemical processes and transformations in living organisms. ... Peptides (from the Greek Ï€ÎµÏ€Ï„Î¿Ï‚, digestible), are the family of short molecules formed from the linking, in a defined order, of various Î±-amino acids. ... Phenylalanine is one of the standard amino acids. ... Look up nucleic acid in Wiktionary, the free dictionary. ... Lactose is a disaccharide found in milk. ... A polyunsaturated triglyceride. ... Many terpenes are derived from conifer resins, here a pine. ... The orange ring surrounding Grand Prismatic Spring is due to carotenoid molecules, produced by huge mats of algae and bacteria. ... Polypyrrole A Polypyrrole (PPy) is a chemical compound formed from a number of connected pyrrole ring structures. ... A cofactor is any substance that needs to be present in addition to an enzyme to catalyze a certain reaction. ... Steroid skeleton of lanosterol. ... Molecular structure of flavone The term flavonoid refers to a class of plant secondary metabolites based around a phenylbenzopyrone structure. ... Chemical structure of ephedrine, a phenethylamine alkaloid An alkaloid is, strictly speaking, a naturally occurring amine produced by a plant,[1] but amines produced by animals and fungi are also called alkaloids. ... Polyketides are secondary metabolites from bacteria, fungi, plants, and animals. ... A glycoside is a molecule where a sugar group is bonded through its anomeric carbon to a nonsugar group by either an oxygen or a nitrogen atom. ... Phenylalanine is one of the standard amino acids. ... Alanine (Ala, A) also 2-aminopropanoic acid is a non-essential Î±-amino acid. ... Physical properties Hazard properties Flash point - N/A R/S statement R: N/A S: N/A RTECS number: N/A Chemical properties Pharmacological properties OrganicBox_complete References a 206-418-1 EINECS for D-alanine a 200-273-8 EINECS for L-alanine a PubChem 602 a PubChem 5950 This... Arginine (symbol Arg or R) is an Î±-amino acid. ... Physical properties Hazard properties Flash point - N/A R/S statement R: N/A S: N/A RTECS number: N/A Chemical properties Pharmacological properties OrganicBox_complete References a EINECS number 205-866-5 ((-)-D-arginine hydrate) a EINECS number 200-811-1 (for L-arginine) a CID 71070 from PubChem... For other articles using the abbreviation or acronym asn see ASN. Asparagine is one of the 20 most common natural amino acids on Earth. ... Physical properties Hazard properties Flash point - N/A R/S statement R: N/A S: N/A RTECS number: N/A Chemical properties Pharmacological properties OrganicBox_complete References a CID 6267 from PubChem (L-asparagine) This article is maintained by WP:Chemicals (Talk) WP:Drugs (Talk) WP:Molecular and Cellular Biology... Aspartic acid (Asp, D), also known as aspartate, the name of its anion, is one of the 20 natural proteinogenic amino acids which are the building blocks of proteins. ... Physical properties Hazard properties Flash point - N/A R/S statement R: N/A S: N/A RTECS number: N/A Chemical properties Pharmacological properties OrganicBox_complete References a CID 424 from PubChem â€” racemic a CID 83887 from PubChem â€” (D-aspartic acid) a CID 5960 from PubChem â€” (L-aspartic acid) a... Cysteine is a naturally occurring, sulfur-containing amino acid that is found in most proteins, although only in small quantities. ... Physical properties Hazard properties Flash point - N/A R/S statement R: N/A S: N/A RTECS number: N/A Chemical properties Pharmacological properties OrganicBox_complete References a [1] This article is maintained by WP:Chemicals (Talk) WP:Drugs (Talk) WP:Molecular and Cellular Biology (Talk) Categories: ... Glutamic acid (Glu, E), is the protonated form of glutamate (the anion). ... Physical properties Hazard properties Flash point - N/A R/S statement R: N/A S: N/A RTECS number: N/A Chemical properties Pharmacological properties OrganicBox_complete References a CID 23327 from PubChem (D-glutamic acid) a CID 33032 from PubChem (L-glutamic acid) This article is maintained by WP:Chemicals... Glutamine is one of the 20 amino acids encoded by the standard genetic code. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete References a CID 738 from PubChem (Gln) a CID 145815 from PubChem (D) a CID 5961 from PubChem (L) ... For the plant, see Glycine (plant). ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete References a EINECS number 200-272-2 a b c d e CID 750 from PubChem (Glycine) ... Histidine is one of the 20 most common natural amino acids present in proteins. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete References a EINECS number 200-745-3 (D-histidine) a EINECS number 206-513-8 (L-histidine) a CID 71083 from PubChem (D-histidine) a CID 6274 from PubChem (L-histidine) ... Isoleucine is one of the 20 natural amino acids, and is coded for in DNA. Its chemical composition is identical to that of leucine, but the arrangement of its atoms is slightly different, resulting in different properties. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete References a b c d e f g PubChem 6306 ... Leucine is one of the 20 most common amino acids and coded for by DNA. It is isomeric with isoleucine. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete References a b c d e PubChem 6106 Categories: | ... Lysine is one of the 20 amino acids normally found in proteins. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete a EINECS number 200-294-2 (Lysine) a CID 866 from PubChem (DL-Lysine) a CID 5962 from PubChem (L-Lysine) Category: ... Methionine is an Î±-amino acid with the chemical formula HO2CCH(NH2)CH2CH2SCH3. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete a 63-68-3 EINECS for L-Methionine a PubChem 876 a PubChem 6137 Category: ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete a EINECS number 200-568-1 (phenylalanine) a CID 994 from PubChem (phenylalanine) a CID 71567 from PubChem (D-phenylalanine) a CID 6140 from PubChem (L-phenylalanine) Category: ... Proline is an Î±-amino acid with the chemical formula HO2CCH(NH[CH2)3]. L-Proline is one of the twenty DNA-encoded amino acids. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete a 205-702-2 EINECS for Proline a PubChem 6148988 a PubChem 6137 Category: ... Serine (IPA ), organic compound, one of the 20 amino acids commonly found in animal proteins. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete a 200-274-3 EINECS for Serine a PubChem 617 a PubChem 5951 Category: ... Threonine is one of the 20 natural amino acids. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete a EINECS number 200-774-1 (Threonine) a CID 69435 from PubChem (D-Threonine) a CID 6288 from PubChem (L-Threonine) Category: ... Tryptophan is an essential amino acid involved in human nutrition. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete a 73-22-3 EINECS for Tryptophan a PubChem 9060 a PubChem 6305 Category: ... Tyrosine (from the Greek tyros, meaning cheese, as it was first discovered in 1846 by German chemist Justus von Liebig in cheese[1][2]), 4-hydroxyphenylalanine, or 2-amino-3(4-hydroxyphenyl)-propanoic acid, is one of the 20 amino acids that are used by cells to synthesize proteins. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete a 200-460-4 EINECS for Tyrosine a PubChem 71098 a PubChem 1153 Category: ... Valine is an amino acid that cannot be synthesized by humans, so it is considered an essential amino acid for human life. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete a 200-773-6 EINECS for Valine a PubChem 71563 a PubChem 1182 Category: ...

Contents

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