Reaction Process: Reactome:R-MTU-936721
Cysteine synthesis from O-acetylserine related metabolites
find 13 related metabolites which is associated with chemical reaction(pathway) Cysteine synthesis from O-acetylserine
OAcSer + S(2-) ⟶ CH3COO- + L-Cys
Adenosine monophosphate
Adenosine monophosphate, also known as adenylic acid or amp, is a member of the class of compounds known as purine ribonucleoside monophosphates. Purine ribonucleoside monophosphates are nucleotides consisting of a purine base linked to a ribose to which one monophosphate group is attached. Adenosine monophosphate is slightly soluble (in water) and a moderately acidic compound (based on its pKa). Adenosine monophosphate can be found in a number of food items such as kiwi, taro, alaska wild rhubarb, and skunk currant, which makes adenosine monophosphate a potential biomarker for the consumption of these food products. Adenosine monophosphate can be found primarily in most biofluids, including blood, feces, cerebrospinal fluid (CSF), and urine, as well as throughout all human tissues. Adenosine monophosphate exists in all living species, ranging from bacteria to humans. In humans, adenosine monophosphate is involved in several metabolic pathways, some of which include josamycin action pathway, methacycline action pathway, nevirapine action pathway, and aspartate metabolism. Adenosine monophosphate is also involved in several metabolic disorders, some of which include hyperornithinemia-hyperammonemia-homocitrullinuria [hhh-syndrome], molybdenum cofactor deficiency, xanthinuria type I, and mitochondrial DNA depletion syndrome. Adenosine monophosphate is a drug which is used for nutritional supplementation, also for treating dietary shortage or imbalanc. Adenosine monophosphate, also known as 5-adenylic acid and abbreviated AMP, is a nucleotide that is found in RNA. It is an ester of phosphoric acid with the nucleoside adenosine. AMP consists of the phosphate group, the pentose sugar ribose, and the nucleobase adenine. AMP can be produced during ATP synthesis by the enzyme adenylate kinase. AMP has recently been approved as a Bitter Blocker additive to foodstuffs. When AMP is added to bitter foods or foods with a bitter aftertaste it makes them seem sweeter. This potentially makes lower calorie food products more palatable. [Spectral] AMP (exact mass = 347.06308) and Guanine (exact mass = 151.04941) and 3,4-Dihydroxy-L-phenylalanine (exact mass = 197.06881) and Glutathione disulfide (exact mass = 612.15196) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] AMP (exact mass = 347.06308) and Glutathione disulfide (exact mass = 612.15196) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] AMP (exact mass = 347.06308) and Adenine (exact mass = 135.0545) 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. Adenosine monophosphate. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=67583-85-1 (retrieved 2024-07-01) (CAS RN: 61-19-8). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). Adenosine monophosphate is a key cellular metabolite regulating energy homeostasis and signal transduction. Adenosine monophosphate is a key cellular metabolite regulating energy homeostasis and signal transduction. Adenosine monophosphate is a key cellular metabolite regulating energy homeostasis and signal transduction.
Coenzyme A
Coenzyme A (CoA, CoASH, or HSCoA) is a coenzyme notable for its role in the synthesis and oxidization of fatty acids and the oxidation of pyruvate in the citric acid cycle. It is adapted from beta-mercaptoethylamine, panthothenate, and adenosine triphosphate. It is also a parent compound for other transformation products, including but not limited to, phenylglyoxylyl-CoA, tetracosanoyl-CoA, and 6-hydroxyhex-3-enoyl-CoA. Coenzyme A is synthesized in a five-step process from pantothenate and cysteine. In the first step pantothenate (vitamin B5) is phosphorylated to 4-phosphopantothenate by the enzyme pantothenate kinase (PanK, CoaA, CoaX). In the second step, a cysteine is added to 4-phosphopantothenate by the enzyme phosphopantothenoylcysteine synthetase (PPC-DC, CoaB) to form 4-phospho-N-pantothenoylcysteine (PPC). In the third step, PPC is decarboxylated to 4-phosphopantetheine by phosphopantothenoylcysteine decarboxylase (CoaC). In the fourth step, 4-phosphopantetheine is adenylylated to form dephospho-CoA by the enzyme phosphopantetheine adenylyl transferase (CoaD). Finally, dephospho-CoA is phosphorylated using ATP to coenzyme A by the enzyme dephosphocoenzyme A kinase (CoaE). Since coenzyme A is, in chemical terms, a thiol, it can react with carboxylic acids to form thioesters, thus functioning as an acyl group carrier. CoA assists in transferring fatty acids from the cytoplasm to the mitochondria. A molecule of coenzyme A carrying an acetyl group is also referred to as acetyl-CoA. When it is not attached to an acyl group, it is usually referred to as CoASH or HSCoA. Coenzyme A is also the source of the phosphopantetheine group that is added as a prosthetic group to proteins such as acyl carrier proteins and formyltetrahydrofolate dehydrogenase. Acetyl-CoA is an important molecule itself. It is the precursor to HMG CoA which is a vital component in cholesterol and ketone synthesis. Furthermore, it contributes an acetyl group to choline to produce acetylcholine in a reaction catalysed by choline acetyltransferase. Its main task is conveying the carbon atoms within the acetyl group to the citric acid cycle to be oxidized for energy production (Wikipedia). Coenzyme A (CoA, CoASH, or HSCoA) is a coenzyme, notable for its role in the synthesis and oxidization of fatty acids, and the oxidation of pyruvate in the citric acid cycle. It is adapted from beta-mercaptoethylamine, panthothenate and adenosine triphosphate. Acetyl-CoA is an important molecule itself. It is the precursor to HMG CoA, which is a vital component in cholesterol and ketone synthesis. Furthermore, it contributes an acetyl group to choline to produce acetylcholine, in a reaction catalysed by choline acetyltransferase. Its main task is conveying the carbon atoms within the acetyl group to the citric acid cycle to be oxidized for energy production. -- Wikipedia [HMDB]. Coenzyme A is found in many foods, some of which are grape, cowpea, pili nut, and summer savory. Coenzyme A (CoASH) is a ubiquitous and essential cofactor, which is an acyl group carrier and carbonyl-activating group for the citric acid cycle and fatty acid metabolism. Coenzyme A plays a central role in the oxidation of pyruvate in the citric acid cycle and the metabolism of carboxylic acids, including short- and long-chain fatty acids[1]. Coenzyme A (CoASH) is a ubiquitous and essential cofactor, which is an acyl group carrier and carbonyl-activating group for the citric acid cycle and fatty acid metabolism. Coenzyme A plays a central role in the oxidation of pyruvate in the citric acid cycle and the metabolism of carboxylic acids, including short- and long-chain fatty acids[1]. Coenzyme A, a ubiquitous essential cofactor, is an acyl group carrier and carbonyl-activating group for the citric acid cycle and fatty acid metabolism. Coenzyme A plays a central role in the metabolism of carboxylic acids, including short- and long-chain fatty acids. Coenzyme A. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=85-61-0 (retrieved 2024-10-17) (CAS RN: 85-61-0). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0).
O-Acetylserine
O-Acetylserine is an α-amino acid with the chemical formula HO2CCH(NH2)CH2OC(O)CH3. It is an intermediate in the biosynthesis of the common amino acid cysteine in bacteria and plants. O-Acetylserine is biosynthesized by acetylation of the serine by the enzyme serine transacetylase. The enzyme O-acetylserine (thiol)-lyase, using sulfide sources, converts this ester into cysteine, releasing acetate. O-Acetylserine belongs to the class of organic compounds known as l-alpha-amino acids. These are alpha amino acids which have the L-configuration of the alpha-carbon atom. O-Acetylserine (OASS) is an acylated amino acid derivative. O-Acetylserine exists in all living species, ranging from bacteria to humans. Outside of the human body, O-Acetylserine has been detected, but not quantified in several different foods, such as okra, vaccinium (blueberry, cranberry, huckleberry), rapes, sparkleberries, and lingonberries. This could make O-acetylserine a potential biomarker for the consumption of these foods. O-acetyl-l-serine, also known as L-serine, acetate (ester) or (2s)-3-acetyloxy-2-aminopropanoate, is a member of the class of compounds known as L-alpha-amino acids. L-alpha-amino acids are alpha amino acids which have the L-configuration of the alpha-carbon atom. O-acetyl-l-serine is soluble (in water) and a moderately acidic compound (based on its pKa). O-acetyl-l-serine can be found in a number of food items such as sorrel, summer savory, purslane, and cherimoya, which makes O-acetyl-l-serine a potential biomarker for the consumption of these food products. O-acetyl-l-serine can be found primarily in blood and urine, as well as in human prostate tissue. O-acetyl-l-serine exists in all living species, ranging from bacteria to humans. Acquisition and generation of the data is financially supported in part by CREST/JST. O-Acetylserine (O-Acetyl-L-serine) is an intermediate in the biosynthesis of the amino acid cysteine in bacteria and plants.
Adenosine phosphosulfate
C10H14N5O10PS (427.01989940000004)
Adenosine phosphosulfate, also known as adenylylsulfate or adenosine sulfatophosphate, belongs to the class of organic compounds known as purine ribonucleoside monophosphates. These are nucleotides consisting of a purine base linked to a ribose to which one monophosphate group is attached. Adenosine phosphosulfate exists in all living species, ranging from bacteria to humans. Within humans, adenosine phosphosulfate participates in a number of enzymatic reactions. In particular, adenosine phosphosulfate can be biosynthesized from sulfate through the action of the enzyme bifunctional 3-phosphoadenosine 5-phosphosulfate synthase 2. In addition, adenosine phosphosulfate can be converted into phosphoadenosine phosphosulfate; which is catalyzed by the enzyme bifunctional 3-phosphoadenosine 5-phosphosulfate synthase 2. In humans, adenosine phosphosulfate is involved in sulfate/sulfite metabolism. Outside of the human body, Adenosine phosphosulfate has been detected, but not quantified in several different foods, such as chia, yardlong beans, swiss chards, sapodilla, and chicory leaves. This could make adenosine phosphosulfate a potential biomarker for the consumption of these foods. An adenosine 5-phosphate having a sulfo group attached to one the phosphate OH groups. Adenosine phosphosulfate (also known as APS) is the initial compound formed by the action of ATP sulfurylase (or PAPS synthetase) on sulfate ions after sulfate uptake. PAPS synthetase 1 is a bifunctional enzyme with both ATP sulfurylase and APS kinase activity, which mediates two steps in the sulfate activation pathway. The first step is the transfer of a sulfate group to ATP to yield adenosine 5-phosphosulfate (APS), and the second step is the transfer of a phosphate group from ATP to APS yielding 3-phosphoadenylylsulfate (PAPS). In mammals, PAPS is the sole source of sulfate; APS appears to be only an intermediate in the sulfate-activation pathway. [HMDB]. Adenosine phosphosulfate is found in many foods, some of which are muskmelon, garlic, caraway, and peach (variety).
Acetyl-CoA
C23H38N7O17P3S (809.1257688000001)
The main function of coenzyme A is to carry acyl groups (such as the acetyl group) or thioesters. Acetyl-CoA is an important molecule itself. It is the precursor to HMG CoA, which is a vital component in cholesterol and ketone synthesis. (wikipedia). acetyl CoA participates in the biosynthesis of fatty acids and sterols, in the oxidation of fatty acids and in the metabolism of many amino acids. It also acts as a biological acetylating agent. The main function of coenzyme A is to carry acyl groups (such as the acetyl group) or thioesters. Acetyl-CoA is an important molecule itself. It is the precursor to HMG CoA, which is a vital component in cholesterol and ketone synthesis. (wikipedia)
Acetic acid
Acetic acid is a two-carbon, straight-chain fatty acid. It is the smallest short-chain fatty acid (SCFA) and one of the simplest carboxylic acids. is an acidic, colourless liquid and is the main component in vinegar. Acetic acid has a sour taste and pungent smell. It is an important chemical reagent and industrial chemical that is used in the production of plastic soft drink bottles, photographic film; and polyvinyl acetate for wood glue, as well as many synthetic fibres and fabrics. In households diluted acetic acid is often used as a cleaning agent. In the food industry acetic acid is used as an acidity regulator. Acetic acid is found in all organisms, from bacteria to plants to humans. The acetyl group, derived from acetic acid, is fundamental to the biochemistry of virtually all forms of life. When bound to coenzyme A (to form acetylCoA) it is central to the metabolism of carbohydrates and fats. However, the concentration of free acetic acid in cells is kept at a low level to avoid disrupting the control of the pH of the cell contents. Acetic acid is produced and excreted in large amounts by certain acetic acid bacteria, notably the Acetobacter genus and Clostridium acetobutylicum. These bacteria are found universally in foodstuffs, water, and soil. Due to their widespread presence on fruit, acetic acid is produced naturally as fruits and many other sugar-rich foods spoil. Several species of anaerobic bacteria, including members of the genus Clostridium and Acetobacterium can convert sugars to acetic acid directly. However, Clostridium bacteria are less acid-tolerant than Acetobacter. Even the most acid-tolerant Clostridium strains can produce acetic acid in concentrations of only a few per cent, compared to Acetobacter strains that can produce acetic acid in concentrations up to 20\\%. Acetic acid is also a component of the vaginal lubrication of humans and other primates, where it appears to serve as a mild antibacterial agent. Acetic acid can be found in other biofluids such as urine at low concentrations. Urinary acetic acid is produced by bacteria such as Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Enterobacter, Acinetobacter, Proteus mirabilis, Citrobacter frundii, Enterococcus faecalis, Streptococcus group B, Staphylococcus saprophyticus (PMID: 22292465). Acetic acid concentrations greater than 30 uM/mM creatinine in the urine can indicate a urinary tract infection, which typically suggests the presence of E. coli or Klebshiella pneumonia in the urinary tract. (PMID: 24909875) Acetic acid is also produced by other bacteria such as Akkermansia, Bacteroidetes, Bifidobacterium, Prevotella and Ruminococcus (PMID: 20444704; PMID: 22292465). G - Genito urinary system and sex hormones > G01 - Gynecological antiinfectives and antiseptics > G01A - Antiinfectives and antiseptics, excl. combinations with corticosteroids > G01AD - Organic acids S - Sensory organs > S02 - Otologicals > S02A - Antiinfectives > S02AA - Antiinfectives D019995 - Laboratory Chemicals > D007202 - Indicators and Reagents D000890 - Anti-Infective Agents > D000900 - Anti-Bacterial Agents It is used for smoking meats and fish C254 - Anti-Infective Agent KEIO_ID A029
Sulfite
Endogenous sulfite is generated as a consequence of the bodys normal processing of sulfur-containing amino acids. Sulfites occur as a consequence of fermentation and also occur naturally in a number of foods and beverages. As food additives, sulfiting agents were first used in 1664 and have been approved in the United States since the 1800s. Sulfite is an allergen, a neurotoxin, and a metabotoxin. An allergen is a compound that causes allergic reactions such as wheezing, rash, or rhinitis. A neurotoxin is a substance that causes damage to nerves or brain tissues. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. As an allergen, sulfite is known to induce asthmatic reactions. Sulfite sensitivity occurs most often in asthmatic adults (predominantly women), but it is also occasionally reported in preschool children. Adverse reactions to sulfites in nonasthmatics are extremely rare. Asthmatics who are steroid-dependent or who have a higher degree of airway hyperreactivity may be at greater risk of experiencing a reaction to sulfite-containing foods. Sulfite sensitivity reactions vary widely, ranging from no reaction to severe. The majority of reactions are mild. These manifestations may include dermatologic, respiratory, or gastrointestinal signs and symptoms. The precise mechanisms of the sensitivity responses have not been completely elucidated: inhalation of sulfur dioxide (SO2) generated in the stomach following ingestion of sulfite-containing foods or beverages, a deficiency in a mitochondrial enzyme, and an IgE-mediated immune response have all been implicated. Exogenously supplied sulfite is detoxified by the enzyme sulfite oxidase. Sulfite oxidase (EC 1.8.3.1) is 1 of 3 enzymes in humans that require molybdenum as a cofactor. Under certain circumstances, chronically high levels of sulfite can lead to serious neurotoxicity. Sulfite oxidase deficiency (also called molybdenum cofactor deficiency) is a rare autosomal inherited disease that is typified by high concentrations of sulfite in the blood and urine. It is characterized by severe neurological symptoms such as untreatable seizures, attenuated growth of the brain, and mental retardation. It results from defects in the enzyme sulfite oxidase, which is responsible for the oxidation of sulfite to sulfate. This sulfite to sulfate reaction is the final step in the degradation of sulfur-containing metabolites (including the amino acids cysteine and methionine). The term "isolated sulfite oxidase deficiency" is used to define the deficiency caused by mutations in the sulfite oxidase gene. This differentiates it from another version of sulfite oxidase deficiency that is due to defects in the molybdenum cofactor biosynthetic pathway (with mutations in the MOCS1 or MOCS2 genes). Isolated sulfite oxidase deficiency is a rare but devastating neurologic disease that usually presents in early infancy with seizures and alterations in muscle tone (PMID: 16234925, 16140720, 8586770). Sulfite oxidase deficiency (as caused by MOCS1 or MOCS2) may be treated with cPMP, a precursor of the molybdenum cofactor (PMID: 20385644). The mechanism behind sulfite neurotoxicity appears to be related to its ability to bind and inhibit glutamate dehydrogenase (GDH). Inhibition of GDH leads to a decrease in alpha-ketoglutarate and a diminished flux through the tricarboxylic acid cycle. This is accompanied by a decrease in NADH through the mitochondrial electron transport chain, which leads to a decrease in mitochondrial membrane potential and in ATP synthesis. Since glutamate is a major metabolite in the brain, inhibition of GDH by sulfite appears to contribute to neural damage characteristic of sulfite oxidase deficiency in human infants (PMID: 15273247). The hydrogen sulfite, or bisulfite, ion is the ion HSO3-. It is the conjugate base of sulfurous acid, H2SO3. Bisulfite has long been recognized as a reagent to react with organic compound... Food additive listed on the EAFUS Food Additive Database (Jan. 2001)
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 .
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])