Reaction Process: BioCyc:CAULONA1000_COMPLETE-ARO-PWY
superpathway of phenylalanine, tyrosine, and tryptophan biosynthesis related metabolites
find 11 related metabolites which is associated with chemical reaction(pathway) superpathway of phenylalanine, tyrosine, and tryptophan biosynthesis
4-hydroxyphenylpyruvate + L-glutamate ⟶ 2-oxoglutarate + L-tyrosine
2-Aminobenzoic acid
2-Aminobenzoic acid, also known as anthranilic acid or O-aminobenzoate, belongs to the class of organic compounds known as aminobenzoic acids. These are benzoic acids containing an amine group attached to the benzene moiety. Within humans, 2-aminobenzoic acid participates in a number of enzymatic reactions. In particular, 2-aminobenzoic acid and formic acid can be biosynthesized from formylanthranilic acid through its interaction with the enzyme kynurenine formamidase. In addition, 2-aminobenzoic acid and L-alanine can be biosynthesized from L-kynurenine through its interaction with the enzyme kynureninase. It is a substrate of enzyme 2-Aminobenzoic acid hydroxylase in benzoate degradation via hydroxylation pathway (KEGG). In humans, 2-aminobenzoic acid is involved in tryptophan metabolism. Outside of the human body, 2-Aminobenzoic acid has been detected, but not quantified in several different foods, such as mamey sapotes, prairie turnips, rowals, natal plums, and hyacinth beans. This could make 2-aminobenzoic acid a potential biomarker for the consumption of these foods. 2-Aminobenzoic acid is a is a tryptophan-derived uremic toxin with multidirectional properties that can affect the hemostatic system. Uremic syndrome may affect any part of the body and can cause nausea, vomiting, loss of appetite, and weight loss. Chronic exposure of uremic toxins can lead to a number of conditions including renal damage, chronic kidney disease and cardiovascular disease. It can also cause changes in mental status, such as confusion, reduced awareness, agitation, psychosis, seizures, and coma. 2-Aminobenzoic acid is an organic compound. It is a substrate of enzyme anthranilate hydroxylase [EC 1.14.13.35] in benzoate degradation via hydroxylation pathway (KEGG). [HMDB]. Anthranilic acid is found in many foods, some of which are butternut squash, sunflower, ginger, and hyssop. Acquisition and generation of the data is financially supported in part by CREST/JST. D002491 - Central Nervous System Agents > D000927 - Anticonvulsants CONFIDENCE standard compound; INTERNAL_ID 8844 CONFIDENCE standard compound; INTERNAL_ID 8009 CONFIDENCE standard compound; INTERNAL_ID 115 KEIO_ID A010
Oxoglutaric acid
Oxoglutaric acid, also known as alpha-ketoglutarate, alpha-ketoglutaric acid, AKG, or 2-oxoglutaric acid, is classified as a gamma-keto acid or a gamma-keto acid derivative. gamma-Keto acids are organic compounds containing an aldehyde substituted with a keto group on the C4 carbon atom. alpha-Ketoglutarate is considered to be soluble (in water) and acidic. alpha-Ketoglutarate is a key molecule in the TCA cycle, playing a fundamental role in determining the overall rate of this important metabolic process (PMID: 26759695). In the TCA cycle, AKG is decarboxylated to succinyl-CoA and carbon dioxide by AKG dehydrogenase, which functions as a key control point of the TCA cycle. Additionally, AKG can be generated from isocitrate by oxidative decarboxylation catalyzed by the enzyme known as isocitrate dehydrogenase (IDH). In addition to these routes of production, AKG can be produced from glutamate by oxidative deamination via glutamate dehydrogenase, and as a product of pyridoxal phosphate-dependent transamination reactions (mediated by branched-chain amino acid transaminases) in which glutamate is a common amino donor. AKG is a nitrogen scavenger and a source of glutamate and glutamine that stimulates protein synthesis and inhibits protein degradation in muscles. In particular, AKG can decrease protein catabolism and increase protein synthesis to enhance bone tissue formation in skeletal muscles (PMID: 26759695). Interestingly, enteric feeding of AKG supplements can significantly increase circulating plasma levels of hormones such as insulin, growth hormone, and insulin-like growth factor-1 (PMID: 26759695). It has recently been shown that AKG can extend the lifespan of adult C. elegans by inhibiting ATP synthase and TOR (PMID: 24828042). In combination with molecular oxygen, alpha-ketoglutarate is required for the hydroxylation of proline to hydroxyproline in the production of type I collagen. A recent study has shown that alpha-ketoglutarate promotes TH1 differentiation along with the depletion of glutamine thereby favouring Treg (regulatory T-cell) differentiation (PMID: 26420908). alpha-Ketoglutarate has been found to be associated with fumarase deficiency, 2-ketoglutarate dehydrogenase complex deficiency, and D-2-hydroxyglutaric aciduria, which are all inborn errors of metabolism (PMID: 8338207). Oxoglutaric acid has been found to be a metabolite produced by Corynebacterium and yeast (PMID: 27872963) (YMDB). [Spectral] 2-Oxoglutarate (exact mass = 146.02152) and S-Adenosyl-L-homocysteine (exact mass = 384.12159) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] 2-Oxoglutarate (exact mass = 146.02152) and (S)-Malate (exact mass = 134.02152) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. Flavouring ingredient
4-Hydroxyphenylpyruvic acid
3-(4-hydroxy-phenyl)pyruvic acid, also known as 4-hydroxy a-oxobenzenepropanoate or 3-(p-hydroxyphenyl)-2-oxopropanoate, belongs to phenylpyruvic acid derivatives class of compounds. Those are compounds containing a phenylpyruvic acid moiety, which consists of a phenyl group substituted at the second position by an pyruvic acid. 3-(4-hydroxy-phenyl)pyruvic acid is slightly soluble (in water) and a moderately acidic compound (based on its pKa). 3-(4-hydroxy-phenyl)pyruvic acid can be synthesized from pyruvic acid. 3-(4-hydroxy-phenyl)pyruvic acid can also be synthesized into 4-hydroxyphenylpyruvic acid oxime. 3-(4-hydroxy-phenyl)pyruvic acid can be found in a number of food items such as garden onion (variety), rose hip, sourdough, and horseradish tree, which makes 3-(4-hydroxy-phenyl)pyruvic acid a potential biomarker for the consumption of these food products. 3-(4-hydroxy-phenyl)pyruvic acid can be found primarily in blood and urine, as well as in human prostate tissue. 3-(4-hydroxy-phenyl)pyruvic acid exists in all eukaryotes, ranging from yeast to humans. In humans, 3-(4-hydroxy-phenyl)pyruvic acid is involved in few metabolic pathways, which include disulfiram action pathway, phenylalanine and tyrosine metabolism, and tyrosine metabolism. 3-(4-hydroxy-phenyl)pyruvic acid is also involved in several metabolic disorders, some of which include tyrosinemia type I, phenylketonuria, tyrosinemia, transient, of the newborn, and alkaptonuria. Moreover, 3-(4-hydroxy-phenyl)pyruvic acid is found to be associated with hawkinsinuria and phenylketonuria. 4-Hydroxyphenylpyruvic acid (4-HPPA) is a keto acid that is involved in the tyrosine catabolism pathway. It is a product of the enzyme (R)-4-hydroxyphenyllactate dehydrogenase (EC 1.1.1.222) and is formed during tyrosine metabolism. The conversion from tyrosine to 4-HPPA is catalyzed by tyrosine aminotransferase. Additionally, 4-HPPA can be converted to homogentisic acid which is one of the precursors to ochronotic pigment. The enzyme 4-hydroxyphenylpyruvic acid dioxygenase (HPD) catalyzes the reaction that converts 4-hydroxyphenylpyruvic acid to homogentisic acid. A deficiency in the catalytic activity of HPD is known to lead to tyrosinemia type III, an autosomal recessive disorder characterized by elevated levels of blood tyrosine and massive excretion of tyrosine derivatives into urine. It has been shown that hawkinsinuria, an autosomal dominant disorder characterized by the excretion of hawkinsin, may also be a result of HPD deficiency (PMID: 11073718). Moreover, 4-hydroxyphenylpyruvic acid is also found to be associated in phenylketonuria, which is also an inborn error of metabolism. There are two isomers of HPPA, specifically 4HPPA and 3HPPA, of which 4HPPA is the most common. 4-HPPA has been found to be a microbial metabolite in Escherichia (ECMDB). KEIO_ID H007 4-Hydroxyphenylpyruvic acid is an intermediate in the metabolism of the amino acid phenylalanine. 4-Hydroxyphenylpyruvic acid is an intermediate in the metabolism of the amino acid phenylalanine.
Phenylpyruvate
Phenylpyruvic acid is a keto-acid that is an intermediate or catabolic byproduct of phenylalanine metabolism. It has a slight honey-like odor. Levels of phenylpyruvate are normally very low in blood or urine. High levels of phenylpyruvic acid can be found in the urine of individuals with phenylketonuria (PKU), an inborn error of metabolism. PKU is due to lack of the enzyme phenylalanine hydroxylase (PAH), so that phenylalanine is converted not to tyrosine but to phenylpyruvic acid. In particular, excessive phenylalanine can be metabolized into phenylketones through, a transaminase pathway route involving glutamate. Metabolites of this transamination reaction include phenylacetate, phenylpyruvate and phenethylamine. In persons with PKU, dietary phenylalanine either accumulates in the body or some of it is converted to phenylpyruvic acid. Individuals with PKU tend to excrete large quantities of phenylpyruvate, phenylacetate and phenyllactate, along with phenylalanine, in their urine. If untreated, mental retardation effects and microcephaly are evident by the first year along with other symptoms which include: unusual irritability, epileptic seizures and skin lesions. Hyperactivity, EEG abnormalities and seizures, and severe learning disabilities are major clinical problems later in life. A "musty or mousy" odor of skin, hair, sweat and urine (due to phenylacetate accumulation); and a tendency to hypopigmentation and eczema are also observed. The neural-development effects of PKU are primarily due to the disruption of neurotransmitter synthesis. In particular, phenylalanine is a large, neutral amino acid which moves across the blood-brain barrier (BBB) via the large neutral amino acid transporter (LNAAT). Excessive phenylalanine in the blood saturates the transporter. Thus, excessive levels of phenylalanine significantly decrease the levels of other LNAAs in the brain. But since these amino acids are required for protein and neurotransmitter synthesis, phenylalanine accumulation disrupts brain development, leading to mental retardation. Phenylpyruvic acid is also a microbial metabolite, it can be produced by Lactobacillus plantarum (PMID: 9687465). Flavouring ingredient Phenylpyruvic acid is used in the synthesis of 3-phenyllactic acid (PLA) by lactate dehydrogenase[1]. Phenylpyruvic acid is used in the synthesis of 3-phenyllactic acid (PLA) by lactate dehydrogenase[1].
Nicotinamide adenine dinucleotide phosphate
NADPH is the reduced form of NADP+, and NADP+ is the oxidized form of NADPH. Nicotinamide adenine dinucleotide phosphate (NADP) is a coenzyme composed of ribosylnicotinamide 5-phosphate (NMN) coupled with a pyrophosphate linkage to 5-phosphate adenosine 2,5-bisphosphate. NADP serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). NADP is formed through the addition of a phosphate group to the 2 position of the adenosyl nucleotide through an ester linkage (Dorland, 27th ed). This extra phosphate is added by the enzyme NAD+ kinase and removed via NADP+ phosphatase. NADP is also known as TPN (triphosphopyridine nucleotide) and it is an important cofactor used in anabolic reactions in all forms of cellular life. Examples include the Calvin cycle, cholesterol synthesis, fatty acid elongation, and nucleic acid synthesis (Wikipedia). Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5-phosphate (NMN) coupled by pyrophosphate linkage to the 5-phosphate adenosine 2,5-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed.) [HMDB]. NADPH is found in many foods, some of which are american pokeweed, rice, ginseng, and ostrich fern. COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
NADP+
[C21H29N7O17P3]+ (744.0832754)
[Spectral] NADP+ (exact mass = 743.07545) and NAD+ (exact mass = 663.10912) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
1,4-Dihydronicotinamide adenine dinucleotide
Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine nucleobase and the other nicotinamide. NAD exists in two forms: an oxidized and reduced form, abbreviated as NAD+ and NADH (H for hydrogen) respectively. NADH is the reduced form of NAD+, and NAD+ is the oxidized form of NADH. NAD (or nicotinamide adenine dinucleotide) is used extensively in glycolysis and the citric acid cycle of cellular respiration. The reducing potential stored in NADH can be either converted into ATP through the electron transport chain or used for anabolic metabolism. ATP "energy" is necessary for an organism to live. Green plants obtain ATP through photosynthesis, while other organisms obtain it via cellular respiration. NAD is a coenzyme composed of ribosylnicotinamide 5-diphosphate coupled to adenosine 5-phosphate by a pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). NADP is formed through the addition of a phosphate group to the 2 position of the adenosyl nucleotide through an ester linkage. NADH is the reduced form of NAD+, and NAD+ is the oxidized form of NADH, A coenzyme composed of ribosylnicotinamide 5-diphosphate coupled to adenosine 5-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). It forms NADP with the addition of a phosphate group to the 2 position of the adenosyl nucleotide through an ester linkage.(Dorland, 27th ed) [HMDB]. NADH is found in many foods, some of which are dill, ohelo berry, fox grape, and black-eyed pea. Acquisition and generation of the data is financially supported in part by CREST/JST. COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
D-Erythrose 4-phosphate
D-Erythrose 4-phosphate is a phosphorylated derivative of erythrose that serves as an important intermediate in the pentose phosphate pathway. It is also used in phenylalanine, tyrosine and tryptophan biosynthesis, and it plays a role in vitamin B6 metabolism (KEGG); Erythrose 4-phosphate is an intermediate in the pentose phosphate pathway and the Calvin cycle. In addition, it serves as a precursor in the biosynthesis of the aromatic amino acids tyrosine, phenylalanine, and tryptophan. D-Erythrose 4-phosphate is found in many foods, some of which are shea tree, bog bilberry, arrowhead, and dock. D-Erythrose 4-phosphate is a phosphorylated derivative of erythrose that serves as an important intermediate in the pentose phosphate pathway. It is also used in phenylalanine, tyrosine and tryptophan biosynthesis, and it plays a role in vitamin B6 metabolism (KEGG). Acquisition and generation of the data is financially supported in part by CREST/JST.
Water
Water is a chemical substance that is essential to all known forms of life. It appears colorless to the naked eye in small quantities, though it is actually slightly blue in color. It covers 71\\% of Earths surface. Current estimates suggest that there are 1.4 billion cubic kilometers (330 million m3) of it available on Earth, and it exists in many forms. It appears mostly in the oceans (saltwater) and polar ice caps, but it is also present as clouds, rain water, rivers, freshwater aquifers, lakes, and sea ice. Water in these bodies perpetually moves through a cycle of evaporation, precipitation, and runoff to the sea. Clean water is essential to human life. In many parts of the world, it is in short supply. From a biological standpoint, water has many distinct properties that are critical for the proliferation of life that set it apart from other substances. It carries out this role by allowing organic compounds to react in ways that ultimately allow replication. All known forms of life depend on water. Water is vital both as a solvent in which many of the bodys solutes dissolve and as an essential part of many metabolic processes within the body. Metabolism is the sum total of anabolism and catabolism. In anabolism, water is removed from molecules (through energy requiring enzymatic chemical reactions) in order to grow larger molecules (e.g. starches, triglycerides and proteins for storage of fuels and information). In catabolism, water is used to break bonds in order to generate smaller molecules (e.g. glucose, fatty acids and amino acids to be used for fuels for energy use or other purposes). Water is thus essential and central to these metabolic processes. Water is also central to photosynthesis and respiration. Photosynthetic cells use the suns energy to split off waters hydrogen from oxygen. Hydrogen is combined with CO2 (absorbed from air or water) to form glucose and release oxygen. All living cells use such fuels and oxidize the hydrogen and carbon to capture the suns energy and reform water and CO2 in the process (cellular respiration). Water is also central to acid-base neutrality and enzyme function. An acid, a hydrogen ion (H+, that is, a proton) donor, can be neutralized by a base, a proton acceptor such as hydroxide ion (OH-) to form water. Water is considered to be neutral, with a pH (the negative log of the hydrogen ion concentration) of 7. Acids have pH values less than 7 while bases have values greater than 7. Stomach acid (HCl) is useful to digestion. However, its corrosive effect on the esophagus during reflux can temporarily be neutralized by ingestion of a base such as aluminum hydroxide to produce the neutral molecules water and the salt aluminum chloride. Human biochemistry that involves enzymes usually performs optimally around a biologically neutral pH of 7.4. (Wikipedia). Water, also known as purified water or dihydrogen oxide, is a member of the class of compounds known as homogeneous other non-metal compounds. Homogeneous other non-metal compounds are inorganic non-metallic compounds in which the largest atom belongs to the class of other nonmetals. Water can be found in a number of food items such as caraway, oxheart cabbage, alaska wild rhubarb, and japanese walnut, which makes water a potential biomarker for the consumption of these food products. Water can be found primarily in most biofluids, including ascites Fluid, blood, cerebrospinal fluid (CSF), and lymph, as well as throughout all human tissues. Water exists in all living species, ranging from bacteria to humans. In humans, water is involved in several metabolic pathways, some of which include cardiolipin biosynthesis CL(20:4(5Z,8Z,11Z,14Z)/18:0/20:4(5Z,8Z,11Z,14Z)/18:2(9Z,12Z)), cardiolipin biosynthesis cl(i-13:0/i-15:0/i-20:0/i-24:0), cardiolipin biosynthesis CL(18:0/18:0/20:4(5Z,8Z,11Z,14Z)/22:5(7Z,10Z,13Z,16Z,19Z)), and cardiolipin biosynthesis cl(a-13:0/i-18:0/i-13:0/i-19:0). Water is also involved in several metabolic disorders, some of which include de novo triacylglycerol biosynthesis tg(i-21:0/i-13:0/21:0), de novo triacylglycerol biosynthesis tg(22:0/20:0/i-20:0), de novo triacylglycerol biosynthesis tg(a-21:0/i-20:0/i-14:0), and de novo triacylglycerol biosynthesis tg(i-21:0/a-17:0/i-12:0). Water is a drug which is used for diluting or dissolving drugs for intravenous, intramuscular or subcutaneous injection, according to instructions of the manufacturer of the drug to be administered [fda label]. Water plays an important role in the world economy. Approximately 70\\% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a major source of food for many parts of the world. Much of long-distance trade of commodities (such as oil and natural gas) and manufactured products is transported by boats through seas, rivers, lakes, and canals. Large quantities of water, ice, and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a wide variety of chemical substances; as such it is widely used in industrial processes, and in cooking and washing. Water is also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, and diving .
Carbon dioxide
Carbon dioxide is a colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals. Carbon dioxide is produced during respiration by all animals, fungi and microorganisms that depend on living and decaying plants for food, either directly or indirectly. It is, therefore, a major component of the carbon cycle. Additionally, carbon dioxide is used by plants during photosynthesis to make sugars which may either be consumed again in respiration or used as the raw material to produce polysaccharides such as starch and cellulose, proteins and the wide variety of other organic compounds required for plant growth and development. When inhaled at concentrations much higher than usual atmospheric levels, it can produce a sour taste in the mouth and a stinging sensation in the nose and throat. These effects result from the gas dissolving in the mucous membranes and saliva, forming a weak solution of carbonic acid. Carbon dioxide is used by the food industry, the oil industry, and the chemical industry. Carbon dioxide is used to produce carbonated soft drinks and soda water. Traditionally, the carbonation in beer and sparkling wine comes about through natural fermentation, but some manufacturers carbonate these drinks artificially. Leavening agent, propellant, aerating agent, preservative. Solvent for supercritical extraction e.g. of caffeine in manufacture of caffeine-free instant coffee. It is used in carbonation of beverages, in the frozen food industry and as a component of controlled atmosphere packaging (CAD) to inhibit bacterial growth. Especies effective against Gram-negative spoilage bacteria, e.g. Pseudomonas V - Various > V03 - All other therapeutic products > V03A - All other therapeutic products > V03AN - Medical gases
Hydrogen Ion
Hydrogen ion, also known as proton or h+, is a member of the class of compounds known as other non-metal hydrides. Other non-metal hydrides are inorganic compounds in which the heaviest atom bonded to a hydrogen atom is belongs to the class of other non-metals. Hydrogen ion can be found in a number of food items such as lowbush blueberry, groundcherry, parsley, and tarragon, which makes hydrogen ion a potential biomarker for the consumption of these food products. Hydrogen ion exists in all living organisms, ranging from bacteria to humans. In humans, hydrogen ion is involved in several metabolic pathways, some of which include cardiolipin biosynthesis cl(i-13:0/a-25:0/a-21:0/i-15:0), cardiolipin biosynthesis cl(a-13:0/a-17:0/i-13:0/a-25:0), cardiolipin biosynthesis cl(i-12:0/i-13:0/a-17:0/a-15:0), and cardiolipin biosynthesis CL(16:1(9Z)/22:5(4Z,7Z,10Z,13Z,16Z)/18:1(11Z)/22:5(7Z,10Z,13Z,16Z,19Z)). Hydrogen ion is also involved in several metabolic disorders, some of which include de novo triacylglycerol biosynthesis TG(20:3(8Z,11Z,14Z)/22:6(4Z,7Z,10Z,13Z,16Z,19Z)/22:5(7Z,10Z,13Z,16Z,19Z)), de novo triacylglycerol biosynthesis TG(18:2(9Z,12Z)/20:0/20:4(5Z,8Z,11Z,14Z)), de novo triacylglycerol biosynthesis TG(18:4(6Z,9Z,12Z,15Z)/18:3(9Z,12Z,15Z)/18:4(6Z,9Z,12Z,15Z)), and de novo triacylglycerol biosynthesis TG(24:0/20:5(5Z,8Z,11Z,14Z,17Z)/24:0). A hydrogen ion is created when a hydrogen atom loses or gains an electron. A positively charged hydrogen ion (or proton) can readily combine with other particles and therefore is only seen isolated when it is in a gaseous state or a nearly particle-free space. Due to its extremely high charge density of approximately 2×1010 times that of a sodium ion, the bare hydrogen ion cannot exist freely in solution as it readily hydrates, i.e., bonds quickly. The hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes. Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions . Hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes. Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions. Under aqueous conditions found in biochemistry, hydrogen ions exist as the hydrated form hydronium, H3O+, but these are often still referred to as hydrogen ions or even protons by biochemists. [Wikipedia])