Reaction Process: BioCyc:META_PWY-7195
pyrimidine ribonucleosides salvage III related metabolites
find 7 related metabolites which is associated with chemical reaction(pathway) pyrimidine ribonucleosides salvage III
H+ + H2O + cytosine ⟶ ammonium + uracil
Cytosine
Cytosine, also known as C, belongs to the class of organic compounds known as pyrimidones. Pyrimidones are compounds that contain a pyrimidine ring, which bears a ketone. Pyrimidine is a 6-membered ring consisting of four carbon atoms and two nitrogen centers at the 1- and 3- ring positions. Cytosine is also classified as a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group at position 2). Cytosine is one of the four main bases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). The nucleoside of cytosine is cytidine. In Watson-Crick base pairing, cytosine forms three hydrogen bonds with guanine. Cytosine was discovered and named by Albrecht Kossel and Albert Neumann in 1894 when it was hydrolyzed from calf thymus tissues. Cytosine exists in all living species, ranging from bacteria to plants to humans. Within cells, cytosine can undergo several enzymatic reactions. It can be methylated into 5-methylcytosine by an enzyme called DNA methyltransferase (DNMT) or be methylated and hydroxylated to make 5-hydroxymethylcytosine. The DNA methyltransferase (DNMT) family of enzymes transfer a methyl group from S-adenosyl-l-methionine (SAM) to the 5’ carbon of cytosine in a molecule of DNA. High levels of cytosine can be found in the urine of individuals with severe combined immunodeficiency syndrome (SCID). Cytosine concentrations as high as (23-160 mmol/mol creatinine) were detected in SCID patients compared to normal levels of <2 mmol/mol creatinine (PMID: 262183). Cytosine is an aminopyrimidine that is pyrimidin-2-one having the amino group located at position 4. It has a role as a human metabolite, an Escherichia coli metabolite, a Saccharomyces cerevisiae metabolite and a mouse metabolite. It is a pyrimidine nucleobase, a pyrimidone and an aminopyrimidine. Cytosine is a metabolite found in or produced by Escherichia coli (strain K12, MG1655). Cytosine is a natural product found in Streptomyces antibioticus, Salmonella enterica, and other organisms with data available. Cytosine is a pyrimidine base found in DNA and RNA that pairs with guanine. Cytosine is a metabolite found in or produced by Saccharomyces cerevisiae. A pyrimidine base that is a fundamental unit of nucleic acids. See also: Pyrimidine (related). A pyrimidine base that is a fundamental unit of nucleic acids. The deamination of cytosine alone is apparent and the nucleotide of cytosine is the prime mutagenic nucleotide in leukaemia and cancer. [HMDB]. Cytosine is found in many foods, some of which are beech nut, turmeric, grass pea, and cucurbita (gourd). An aminopyrimidine that is pyrimidin-2-one having the amino group located at position 4. Cytosine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=71-30-7 (retrieved 2024-07-01) (CAS RN: 71-30-7). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). Cytosine is one of the four main bases found in DNA and RNA. Cytosine modifications exhibit circadian oscillations that are involved in epigenetic diversity and aging[1][2]. Cytosine is one of the four main bases found in DNA and RNA. Cytosine modifications exhibit circadian oscillations that are involved in epigenetic diversity and aging[1][2]. Cytosine is one of the four main bases found in DNA and RNA. Cytosine modifications exhibit circadian oscillations that are involved in epigenetic diversity and aging[1][2].
Cytidine
Cytidine is a nucleoside that is composed of the base cytosine linked to the five-carbon sugar D-ribose. Cytidine is a pyrimidine that besides being incorporated into nucleic acids, can serve as a substrate for the salvage pathway of pyrimidine nucleotide synthesis. It is a precursor of cytidine triphosphate (CTP) needed in the phosphatidylcholine (PC) and phosphatidylethanolamine (PE) biosynthetic pathways. These variations probably reflect the species differences in cytidine deaminase, the enzyme that converts cytidine to uridine in the body. The transport of cytidine into the brains extracellular fluid, and then into neurons and glia, are essential prerequisites for cytidine to be utilized in the brain. An efficient mechanism mediating the brain uptake of circulating cytidine has not yet been demonstrated. The biosynthesis of PC, the most abundant phosphatide in the brain, via the Kennedy pathway requires phosphocholine and cytidine triphosphate (CTP), a cytidine nucleotide involved in the rate-limiting step. The enzyme that converts CTP to endogenous CDP-choline (CTP:phosphocholine cytidylyltransferase) is unsaturated at physiological brain CTP levels. APOBEC is a family of enzymes that has been discovered with the ability to deaminate cytidines on RNA or DNA. The human apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G protein (APOBEC3G, or hA3G), provides cells with an intracellular antiretroviral activity that is associated with the hypermutation of viral DNA through cytidine deamination. Indeed, hA3G belongs to a family of vertebrate proteins that contains one or two copies of a signature sequence motif unique to cytidine deaminases (CTDAs) (PMID: 16769123, 15780864, 16720547). Cytidine is a nucleoside that is composed of the base cytosine linked to the five-carbon sugar D-ribose. Cytidine is a pyrimidine that besides being incorporated into nucleic acids, can serve as substrate for the salvage pathway of pyrimidine nucleotide synthesis; as precursor of the cytidine triphosphate (CTP) needed in the phosphatidylcholine (PC) and phosphatidylethanolamine (PE) biosynthetic pathway. These variations probably reflect the species differences in cytidine deaminase, the enzyme that converts cytidine to uridine in the body. The transports of cytidine into the brains extracellular fluid, and then into neurons and glia, are essential prerequisites for cytidine to be utilized in brain. An efficient mechanism mediating the brain uptake of circulating cytidine has not yet been demonstrated. The biosynthesis of PC, the most abundant phosphatide in the brain, via the Kennedy pathway requires phosphocholine and cytidine triphosphate (CTP), a cytidine nucleotide, which is involved in the rate-limiting step. The enzyme that converts CTP to endogenous CDP-choline (CTP: phosphocholine cytidylyltransferase) is unsaturated at physiological brain CTP levels. Cytidine is a white crystalline powder. (NTP, 1992) Cytidine is a pyrimidine nucleoside in which cytosine is attached to ribofuranose via a beta-N(1)-glycosidic bond. It has a role as a human metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite and a mouse metabolite. It is functionally related to a cytosine. Cytidine is a metabolite found in or produced by Escherichia coli (strain K12, MG1655). Cytidine is a natural product found in Fritillaria thunbergii, Castanopsis fissa, and other organisms with data available. Cytidine is a pyrimidine nucleoside comprised of a cytosine bound to ribose via a beta-N1-glycosidic bond. Cytidine is a precursor for uridine. Both cytidine and uridine are utilized in RNA synthesis. Cytidine is a metabolite found in or produced by Saccharomyces cerevisiae. A pyrimidine nucleoside that is composed of the base CYTOSINE linked to the five-carbon sugar D-RIBOSE. A pyrimidine nucleoside in which cytosine is attached to ribofuranose via a beta-N(1)-glycosidic bond. [Spectral] Cytidine (exact mass = 243.08552) and 3,4-Dihydroxy-L-phenylalanine (exact mass = 197.06881) and NAD+ (exact mass = 663.10912) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] Cytidine (exact mass = 243.08552) and 3,4-Dihydroxy-L-phenylalanine (exact mass = 197.06881) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] Cytidine (exact mass = 243.08552) 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. Cytidine is a pyrimidine nucleoside and acts as a component of RNA. Cytidine is a precursor of uridine. Cytidine controls neuronal-glial glutamate cycling, affecting cerebral phospholipid metabolism, catecholamine synthesis, and mitochondrial function[1][2][3]. Cytidine is a pyrimidine nucleoside and acts as a component of RNA. Cytidine is a precursor of uridine. Cytidine controls neuronal-glial glutamate cycling, affecting cerebral phospholipid metabolism, catecholamine synthesis, and mitochondrial function[1][2][3]. Cytidine is a pyrimidine nucleoside and acts as a component of RNA. Cytidine is a precursor of uridine. Cytidine controls neuronal-glial glutamate cycling, affecting cerebral phospholipid metabolism, catecholamine synthesis, and mitochondrial function[1][2][3].
Uracil
Uracil, also known as U, belongs to the class of organic compounds known as pyrimidones. Pyrimidones are compounds that contain a pyrimidine ring, which bears a ketone. Pyrimidine is a 6-membered ring consisting of four carbon atoms and two nitrogen centers at the 1- and 3- ring positions. Uracil is a common naturally occurring pyrimidine found in RNA. It base pairs with adenine and is replaced by thymine in DNA. Uracil is one of the four nucleobases in RNA that are represented by the letters A, G, C and U. Methylation of uracil produces thymine. The name "uracil" was coined in 1885 by the German chemist Robert Behrend, who was attempting to synthesize derivatives of uric acid. Originally discovered in 1900, uracil was isolated by hydrolysis of yeast nuclein that was found in bovine thymus and spleen, herring sperm, and wheat germ. Uracil exists in all living species, ranging from bacteria to plants to humans. Uracils use in the body is to help carry out the synthesis of many enzymes necessary for cell function through bonding with riboses and phosphates. Uracil serves as an allosteric regulator and a coenzyme for many important biochemical reactions. Uracil (via the nucleoside uridine) can be phosphorylated by various kinases to produce UMP, UDP and UTP. UDP and UTP regulate carbamoyl phosphate synthetase II (CPSase II) activity in animals. Uracil is also involved in the biosynthesis of polysaccharides and in the transport of sugars containing aldehydes. Within humans, uracil participates in a number of enzymatic reactions. In particular, uracil and ribose 1-phosphate can be biosynthesized from uridine; which is mediated by the enzyme uridine phosphorylase 2. In addition, uracil can be converted into dihydrouracil through the action of the enzyme dihydropyrimidine dehydrogenase [NADP(+)]. Uracil is rarely found in DNA, and this may have been an evolutionary change to increase genetic stability. This is because cytosine can deaminate spontaneously to produce uracil through hydrolytic deamination. Therefore, if there were an organism that used uracil in its DNA, the deamination of cytosine (which undergoes base pairing with guanine) would lead to formation of uracil (which would base pair with adenine) during DNA synthesis. Uracil can be used for drug delivery and as a pharmaceutical. When elemental fluorine reacts with uracil, it produces 5-fluorouracil. 5-Fluorouracil is an anticancer drug (antimetabolite) that mimics uracil during the nucleic acid (i.e. RNA) synthesis and transcription process. Because 5-fluorouracil is similar in shape to, but does not undergo the same chemistry as, uracil, the drug inhibits RNA replication enzymes, thereby blocking RNA synthesis and stopping the growth of cancerous cells. Uracil is a common and naturally occurring pyrimidine derivative. Originally discovered in 1900, it was isolated by hydrolysis of yeast nuclein that was found in bovine thymus and spleen, herring sperm, and wheat germ. It is a planar, unsaturated compound that has the ability to absorb light. Uracil. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=66-22-8 (retrieved 2024-07-01) (CAS RN: 66-22-8). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). Uracil is a common and naturally occurring pyrimidine derivative and one of the four nucleobases in the nucleic acid of RNA. Uracil is a common and naturally occurring pyrimidine derivative and one of the four nucleobases in the nucleic acid of RNA. Uracil is a common and naturally occurring pyrimidine derivative and one of the four nucleobases in the nucleic acid of RNA.
D-Ribose
D-Ribose, commonly referred to as simply ribose, is a five-carbon sugar found in all living cells. Ribose is not an essential nutrient because it can be synthesized by almost every tissue in the body from other substances, such as glucose. It is vital for life as a component of DNA, RNA, ATP, ADP, and AMP. In nature, small amounts of ribose can be found in ripe fruits and vegetables. Brewers yeast, which has a high concentration of RNA, is another rich source of ribose. D-ribose is also a component of many so-called energy drinks and anti-ageing products available on the market today. Ribose is a structural component of ATP, which is the primary energy source for exercising muscle. The adenosine component is an adenine base attached to the five-carbon sugar ribose. ATP provides energy to working muscles by releasing a phosphate group, hence becoming ADP, which in turn may release a phosphate group, then becoming AMP. During intense muscular activity, the total amount of ATP available is quickly depleted. In an effort to correct this imbalance, AMP is broken down in the muscle and secreted from the cell. Once the breakdown products of AMP are released from the cell, the energy potential (TAN pool) of the muscle is reduced and ATP must then be reformed using ribose. Ribose helps restore the level of adenine nucleotides by bypassing the rate-limiting step in the de novo (oxidative pentose phosphate) pathway, which regenerates phosphoribosyl pyrophosphate (PRPP), the essential precursor for ATP. If ribose is not readily available to a cell, glucose may be converted to ribose. Ribose supplementation has been shown to increase the rate of ATP resynthesis following intense exercise. The use of ribose in men with severe coronary artery disease resulted in improved exercise tolerance. Hence, there is interest in the potential of ribose supplements to boost muscular performance in athletic activities (PMID: 17618002, Curr Sports Med Rep. 2007 Jul;6(4):254-7.). Ribose, also known as D-ribose or alpha-delta-ribose-5, is a member of the class of compounds known as pentoses. Pentoses are monosaccharides in which the carbohydrate moiety contains five carbon atoms. Ribose is very soluble (in water) and a very weakly acidic compound (based on its pKa). Ribose can be found in a number of food items such as lemon verbena, devilfish, watercress, and chicory roots, which makes ribose a potential biomarker for the consumption of these food products. Ribose can be found primarily in most biofluids, including urine, cerebrospinal fluid (CSF), saliva, and feces, as well as throughout most human tissues. Ribose exists in all living species, ranging from bacteria to humans. In humans, ribose is involved in the pentose phosphate pathway. Ribose is also involved in few metabolic disorders, which include glucose-6-phosphate dehydrogenase deficiency, ribose-5-phosphate isomerase deficiency, and transaldolase deficiency. Moreover, ribose is found to be associated with ribose-5-phosphate isomerase deficiency. The ribose β-D-ribofuranose forms part of the backbone of RNA. It is related to deoxyribose, which is found in DNA. Phosphorylated derivatives of ribose such as ATP and NADH play central roles in metabolism. cAMP and cGMP, formed from ATP and GTP, serve as secondary messengers in some signalling pathways . D-Ribose(mixture of isomers) is an energy enhancer, and acts as a sugar moiety of ATP, and widely used as a metabolic therapy supplement for chronic fatigue syndrome or cardiac energy metabolism. D-Ribose(mixture of isomers) is active in protein glycation, induces NF-κB inflammation in a RAGE-dependent manner[1]. D-Ribose(mixture of isomers) is an energy enhancer, and acts as a sugar moiety of ATP, and widely used as a metabolic therapy supplement for chronic fatigue syndrome or cardiac energy metabolism. D-Ribose(mixture of isomers) is active in protein glycation, induces NF-κB inflammation in a RAGE-dependent manner[1]. D-Ribose(mixture of isomers) is an energy enhancer, and acts as a sugar moiety of ATP, and widely used as a metabolic therapy supplement for chronic fatigue syndrome or cardiac energy metabolism. D-Ribose(mixture of isomers) is active in protein glycation, induces NF-κB inflammation in a RAGE-dependent manner[1].
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 .
Ammonium
Ammonium, also known as ammonium(1+) or nh4+, 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. Ammonium can be found in a number of food items such as irish moss, sago palm, sorghum, and malabar spinach, which makes ammonium a potential biomarker for the consumption of these food products. Ammonium can be found primarily in blood and sweat. Ammonium exists in all living species, ranging from bacteria to humans. In humans, ammonium is involved in the the oncogenic action of 2-hydroxyglutarate. Ammonium is also involved in a couple of metabolic disorders, which include the oncogenic action of d-2-hydroxyglutarate in hydroxygluaricaciduria and the oncogenic action of l-2-hydroxyglutarate in hydroxygluaricaciduria. Moreover, ammonium is found to be associated with n-acetylglutamate synthetase deficiency. The ammonium cation is a positively charged polyatomic ion with the chemical formula NH+ 4. It is formed by the protonation of ammonia (NH3). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations (NR+ 4), where one or more hydrogen atoms are replaced by organic groups (indicated by R) . Ammonium is an important source of nitrogen for many plant species, especially those growing on hypoxic soils. However, it is also toxic to most crop species and is rarely applied as a sole nitrogen source. The ammonium (more obscurely: aminium) cation is a positively charged polyatomic cation with the chemical formula NH4+. It is formed by the protonation of ammonia (NH3). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations (NR4+), where one or more hydrogen atoms are replaced by organic radical groups (indicated by R). Ammonium is found to be associated with N-acetylglutamate synthetase deficiency, which is an inborn error of metabolism.
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])
