zwitterion comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-10-31. Where a claim depends on a specific study, the study is described rather than over-claimed.
In chemical terms, creatine monohydrate is often described as N-(aminoiminomethyl)-N-methylglycine monohydrate, though nomenclature varies. Its solid state consists of zwitterionic creatine molecules linked with water through hydrogen bonding. The compound dissolves in water, but dissolution rate depends on particle size, temperature, and agitation. Once dissolved, the hydrate water becomes part of the solvent, leaving free creatine in solution. The monohydrate is not the same as creatine anhydrous, which lacks the water of crystallization and has a higher creatine fraction by mass.
Commercial creatine monohydrate is typically a white to off-white powder with low odor. It is commonly sold as a fine powder, micronized powder, or larger crystals, but these are physical forms of the same chemical. Purity grades vary, and products may contain small amounts of related substances such as creatinine, dicyandiamide, or moisture. The monohydrate is often selected for supplements and research because its production is well established and its behavior in water is predictable. Analytical certificates usually report assay, loss on drying, and heavy metals.
Creatine monohydrate is a crystalline compound formed from creatine and one water molecule in its solid lattice. Creatine itself is a nitrogen-containing organic acid involved in energy transfer in muscle and other tissues. The monohydrate form is the most common solid form used in research and commercial products because it is stable and easy to handle. The term "monohydrate" refers to the fixed one-to-one ratio of water to creatine in the crystal, not to moisture content. This distinction matters when comparing labels or calculating creatine content.
Creatine monohydrate is sold as a dietary ingredient in some countries and as a food supplement in others. Regulatory frameworks vary, so purity limits, labeling rules, and permitted claims are not globally uniform. In the United States, it falls under dietary supplement rules, whereas the European Union treats it as a food supplement ingredient. Pharmacopeial monographs, where they exist, can provide public quality standards, but not every product is required to meet them. Questions about long-term effects and patterns of use remain areas of active study rather than settled regulatory findings.
Solid creatine monohydrate is generally stable when kept cool and dry, but it can hydrolyze to creatinine over time. Moisture, heat, and acidic conditions accelerate this conversion, which reduces assay values and changes the material's properties. Creatinine is a cyclic dehydration product that is also a normal human metabolite, so its presence in a sample is not necessarily a health concern by itself. In quality testing, creatinine is monitored as a marker of degradation and purity.
| Property | Value | Notes |
|---|---|---|
| Chemical name | N-(aminoiminomethyl)-N-methylglycine monohydrate | Nomenclature varies across sources. |
| Common synonyms | Creatine hydrate; creatine monohydrate | “Monohydrate” specifies one water per creatine. |
| Appearance | White to off-white crystalline powder | Particle size and flowability vary by grade. |
| Solubility class | Soluble in water; slightly soluble in ethanol | Dissolution increases with temperature and stirring. |
| Typical storage | Tightly closed container at 15–25 °C | Protect from moisture and excessive heat. |
Identity and purity are commonly assessed by high-performance liquid chromatography, often with ultraviolet detection, and by spectroscopic techniques such as infrared or nuclear magnetic resonance. These methods can distinguish creatine from creatinine and detect related impurities. Moisture content may be measured by Karl Fischer titration or loss on drying. Particle size, bulk density, and heavy metal limits are additional quality parameters. Not every product is tested by every method, so specifications depend on the intended use and regulatory framework.
Solid creatine monohydrate is generally stable when kept dry and protected from extremes of heat and humidity. In the presence of moisture, it can gradually convert to creatinine, a cyclic dehydration product that has little value for phosphocreatine synthesis. Elevated temperatures and acidic conditions accelerate this conversion in solution. Because the reaction is slow in cool, dry storage, typical shelf lives are measured in years rather than weeks. Packaging that limits moisture and oxygen exposure helps maintain purity.
Part-time training was compulsory for all white males between 18 and 55, with a small number of exceptions for those in reserved occupations. On 25 May 1940 Southern Rhodesia, the last country to join the EATS, became the first to start operating an air school under it, beating Canada by a week. The SRAF was absorbed into the British Royal Air Force in April 1940, with No. 1 Squadron becoming No. 237 Squadron. The RAF subsequently designated two more Rhodesian squadrons, namely No. 266 Squadron in 1940 and No. 44 Squadron in 1941, in a manner similar to the Article XV squadrons from Australia, Canada and New Zealand.
The reaction proceeds in three oxidations, each catalysed by the enzyme, which is a cytochrome P450 protein containing heme, isolated from Artemisia annua. It requires a partner cytochrome P450 reductase for functional expression. This uses nicotinamide adenine dinucleotide phosphate. The product is used by the plant in the biosynthesis of artemisinin.
As of 2019, the pathophysiology is largely not understood, although it is increasingly becoming accepted that calcium dysregulation plays a role. Calpain 3 is unique from other calpain proteases in that it is relatively specific to muscle. Calpain 3 is both a protease and a structural protein. As a protease, it cleaves proteins of the sarcomere and cytoskeleton, designating them to be degraded by proteasomes, a part of muscle remodeling. The structural role of calpain 3 is stabilization of the triad protein complexes. A triad protein complex plays a role converting electrical excitation into calcium release, and it is composed of two calcium channels, the ryanodine receptor (RYR1), and the dihydropyridine receptor (DHPR). With calpain 3 mutation, proteins typically found at the triad are reduced, including CaMKII (Ca2+/calmodulin-dependent protein kinase II). Decreased CaMKII activity impairs induction of slow oxidative gene expression, which in turn impairs genes involving the mitochondria and lipid metabolism.
In the anterior pituitary, the term "acidophil" is used to describe two different types of cells which stain well with acidic dyes. Somatotrophs, which secrete growth hormone (a peptide hormone) Lactotrophs, which secrete prolactin (a peptide hormone) When using standard staining techniques, they cannot be distinguished from each other (though they can be distinguished from basophils and chromophobes), and are therefore identified simply as "acidophils". Eosinophilic Acidophile (histology) Basophilic Chromophobe cell Melanotroph Chromophil Basophil cell Oxyphil cell Oxyphil cell (parathyroid) Pituitary gland Neuroendocrine cell
The structures of human P-TEFb containing Cdk9 and cyclin T1 and the HIV Tat•P-TEFb complex have been solved using X-ray crystallography. The first structure solved demonstrated that the two subunits were arranged as has been found in other cyclin dependent kinases. Three amino acid substitutions were inadvertently introduced in the subunits used for the original structure and a subsequent structure determination using the correct sequences demonstrated the same overall structure except for a few significant changes around the active site. The structure of HIV Tat bound to P-TEFb demonstrated that the viral protein forms extensive contacts with the cyclin T1 subunit (Figure 2).
Sources: en.wikipedia.org
== Alleged ruthenium-106 leak == In September 2017 an estimated amount of 100 to 300 TBq (0.3 to 1 g) of 106Ru was released in Russia, probably in the Ural region. It was, after ruling out release from a reentering satellite, concluded that the source was either in nuclear fuel cycle facilities or radioactive source production. In France levels up to 0.036mBq/m3 of air were measured. It was estimated that for distances of the order of a few tens of kilometres, contamination levels may have exceeded the limits for non-dairy foodstuffs.
The first whole genome sequencing study to comprehensively catalog de novo structural variation at a much higher resolution than DNA microarray studies has shown that the mutation rate is approximately 20% and not elevated in autism compared to sibling controls. Structural variants in individuals with autism are much larger and four times more likely to disrupt genes, mirroring findings from CNV studies. CNV studies were closely followed by exome sequencing studies, which sequence the 1–2% of the genome that codes for proteins (the "exome"). These studies found that de novo gene inactivating mutations were observed in approximately 20% of individuals with autism, compared to 10% of unaffected siblings, suggesting the etiology of autism is driven by these mutations in around 10% of cases. There are predicted to be 350-450 genes that significantly increase susceptibility to autism when impacted by inactivating de novo mutations. A further 12% of cases are predicted to be caused by protein altering missense mutations that change an amino acid but do not inactivate a gene. Therefore, approximately 30% of individuals with autism have a spontaneous de novo large CNV that deletes or duplicates genes, or mutation that changes the amino acid code of an individual gene. A further 5–10% of cases have inherited structural variation at loci known to be associated with autism, and these known structural variants may arise de novo in the parents of affected children.
=== Early history (1900–1946) === The origins of football in Colombia are disputed, as no single city or date is universally accepted. Most accounts place the first organised matches in the early 20th century on the Caribbean coast, particularly around Barranquilla and Santa Marta, where British railway workers on the Puerto Colombia line and English sailors introduced association football to local communities. Bogotá and Pasto have also laid claim to the sport's introduction, and among the earliest documented fixtures is an October 1909 friendly in Santa Marta between a United Fruit Company works team fielding English players and a side of local labourers. One documented account places the first match on 6 August 1904, when executives and workers of The Colombia Railways Company played in Barranquilla, following informal games organised by employees since around 1900. Colombian football's first governing body was founded in Barranquilla on 12 October 1924 as the Liga de Football del Atlántico, gaining legal recognition from the national government by resolution in 1927. Reconstituted as the Asociación Colombiana de Fútbol, it joined both FIFA and CONMEBOL in 1936, and adopted its present name, the Colombian Football Federation, upon receiving definitive FIFA recognition in 1971. Colombia's first recorded international match came on 17 February 1926, when a side representing the Atlantic coast and playing as Selección Atlántico defeated Costa Rica 4–1 at the Estadio Moderno Julio Torres in Barranquilla.
When a surface is immersed in a solution containing electrolytes, it develops a net surface charge. This is often because of ionic adsorption. Aqueous solutions universally contain positive and negative ions (cations and anions, respectively), which interact with partial charges on the surface, adsorbing to and thus ionizing the surface and creating a net surface charge. This net charge results in a surface potential [L], which causes the surface to be surrounded by a cloud of counter-ions, which extends from the surface into the solution, and also generally results in repulsion between particles. The larger the partial charges in the material, the more ions are adsorbed to the surface, and the larger the cloud of counter-ions. A solution with a higher concentration of electrolytes also increases the size of the counter-ion cloud. This ion/counterion layer is known as the electric double layer. A solution's pH can also greatly affect surface charge because functional groups present on the surface of particles can often contain oxygen or nitrogen, two atoms which can be protonated or deprotonated to become charged. Thus, as the concentration of hydrogen ions changes, so does the surface charge of the particles. At a certain pH, the average surface charge will be equal to zero; this is known as the point of zero charge (PZC). A list of common substances and their associated PZCs is shown to the right.
== External links == "Peptide P518 Receptor". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. This article incorporates text from the United States National Library of Medicine, which is in the public domain.
Sources: en.wikipedia.org
It is a solid form of creatine that contains one water molecule per creatine molecule in the crystal lattice. The hydrate water is part of the crystal structure rather than loose moisture. The term is often used for the common crystalline powder grade.
Creatine anhydrous lacks the water of crystallization and therefore contains a higher creatine fraction by mass. The monohydrate is more common in commerce and research because it is stable and easy to handle. The two forms are not identical in solid state, though both yield creatine when dissolved.
Creatine is the base molecule, while creatine monohydrate is a hydrate of that molecule. Once dissolved, the hydrate water becomes part of the solvent and free creatine is present. In casual usage the names are often shortened to creatine, but the solid forms differ.
A sealed container kept at room temperature and away from moisture is typical. Heat and humidity promote conversion to creatinine and can reduce assay values. Long-term storage under dry conditions helps maintain the original crystalline form.