The short version of tripeptide fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-06-24. Anything still debated is marked as such rather than presented as settled.
Glutathione is a small tripeptide made of glutamic acid, cysteine, and glycine. Its cysteine thiol group allows reversible oxidation and reduction, making it central to cellular redox chemistry. The reduced form, often abbreviated GSH, predominates inside most cells, while the oxidized disulfide form, GSSG, forms when two GSH molecules react. The ratio of GSH to GSSG is widely used as an indicator of oxidative stress in laboratory research, though it does not by itself diagnose a clinical condition.
Biosynthesis occurs in two ATP-dependent steps. The enzyme glutamate-cysteine ligase joins glutamate and cysteine, forming gamma-glutamylcysteine; glutathione synthetase then adds glycine to produce the complete tripeptide. Because the peptide bond from glutamate uses the gamma-carboxyl group, glutathione resists digestion by many ordinary peptidases. Tissues vary in synthesis capacity, and the liver generally contains high concentrations relative to many other organs. This uneven distribution contributes to organ-specific differences in redox buffering and affects how experimental results are interpreted across tissue types.
Glutathione is synthesized in two ATP-dependent steps. First, gamma-glutamylcysteine synthetase links glutamate and cysteine; second, glutathione synthetase adds glycine to form the complete tripeptide. The pathway is feedback-inhibited by GSH itself, which helps maintain steady intracellular levels. Tissues vary widely in glutathione content, with the liver typically containing the highest concentrations, followed by the kidneys, lungs, and erythrocytes. Because cysteine is often limiting, its availability influences synthesis rates, and regulation of this pathway varies by cell type.
Glutathione serves as a cofactor for several enzymes, including glutathione peroxidase and glutathione S-transferase. These enzymes help reduce hydrogen peroxide and lipid peroxides, and they conjugate reactive electrophiles for excretion. The molecule also acts as a reservoir for cysteine, an amino acid that is prone to oxidation. In addition, glutathione participates in the metabolism of nitric oxide, leukotrienes, and prostaglandins. Its roles extend to cell signaling, apoptosis, and the regulation of protein function through S-glutathionylation.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C10H17N3O6S | Reduced glutathione (GSH); oxidized form differs by disulfide linkage. |
| Molar mass | 307.32 g/mol | Calculated for the reduced tripeptide. |
| Appearance | White to off-white crystalline powder | Typical laboratory reagent description. |
| Solubility | Soluble in water | Aqueous solutions are acidic; solubility depends on pH and salt form. |
| CAS Registry Number | 70-18-8 | Refers to reduced L-glutathione; oxidized form has a different number. |
Functionally, glutathione supports redox balance by donating electrons and becoming oxidized. It also serves as a cofactor for enzymes such as glutathione peroxidases and glutathione S-transferases. These enzymes participate in peroxide reduction and in conjugation reactions that help process reactive molecules. Separate from antioxidant roles, glutathione can modify protein cysteines through S-glutathionylation, influencing enzyme activity and signaling. Research continues to examine how these chemical roles translate into whole-organism effects.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. Its glutamate-cysteine linkage uses the gamma-carboxyl group of glutamate, a feature that resists standard peptidases. The cysteine residue provides a thiol group, which gives the molecule its reducing character. In cells, glutathione is often the most abundant small-molecule thiol, with concentrations varying widely by tissue and compartment. It exists mainly in a reduced form called GSH, while oxidation produces a disulfide-linked dimer called GSSG.
Biosynthesis proceeds in two ATP-dependent steps. First, glutamate-cysteine ligase joins glutamate and cysteine. Second, glutathione synthetase adds glycine to the intermediate. The pathway is regulated by cysteine availability, enzyme expression, and feedback inhibition by glutathione itself. Liver tissue has a particularly high capacity for synthesis and export. Because the molecule is made inside cells, circulating glutathione reflects a balance of release, uptake, and breakdown rather than simple dietary supply.
Quality control for glutathione focuses on identity, purity, and oxidation state. Certificates of analysis may report assay value, water content, and the presence of GSSG or other impurities. Chromatographic purity is often expressed as a percentage of peak area. Reference standards help laboratories compare results across instruments and batches. Because glutathione is a small, polar molecule, separation from cysteine, gamma-glutamylcysteine, and related thiols can be challenging. Verification often combines more than one analytical technique.
Measuring glutathione requires attention to sample preparation because the molecule oxidizes readily. Blood, tissue, and cell samples are often treated with acid to precipitate proteins and stabilize the thiol. Without such steps, GSH can convert to GSSG or form mixed disulfides during storage. Analytical methods include spectrophotometric assays, high-performance liquid chromatography, and mass spectrometry. Each approach has different sensitivity, specificity, and susceptibility to interference from related compounds in complex matrices.
=== Asexual === All known cnidarians can reproduce asexually by various means, in addition to regenerating after being fragmented. Hydrozoan polyps only bud, while the medusae of some hydrozoans can divide down the middle. Scyphozoan polyps can both bud and split down the middle. In addition to both of these methods, Anthozoa can split horizontally just above the base. Asexual reproduction makes the daughter cnidarian a clone of the adult. The ability of cnidarians to asexually reproduce ensures a greater number of mature medusa that can mature to reproduce sexually.
Trump signs a bill to fund the Department of Homeland Security, the Secret Service, the Coast Guard, FEMA, TSA, and the Cybersecurity and Infrastructure Security Agency, ending a 76-day partial government shutdown. In ice hockey, the Minnesota Wild defeat the Dallas Stars in six games in the 2026 Stanley Cup playoffs following a 5–2 victory to win a playoff series for the first time since 2015, ending an 11-year drought.
ALK-positive ALCL occurs mostly but not exclusively in children and young adults and is slightly more common in males. Most individuals present with stage III or IV (i.e. advanced) disease. They evidence systemic symptoms including B symptoms such as fever, night sweats, and weight loss in 75% of cases; lymph node enlargement (90%) including those in the mediastinum (36%); and lymphomatous lesions in the skin (26%), bone (14%), soft tissues (15%), lung (12%), and/or liver (8%). Tumor cells are found in the bone marrow in up to 40% of the cases when immunohistochemical analysis is performed. Involvement of the central nervous system or a leukemia-like circulation of malignant cells in the blood occurs only very rarely. Most patients, including up to 90% of young children and adolescents, have circulating autoantibodies directed against the ALK fusion protein expressed by their tumor cells.
Synthesis of RNA typically occurs in the cell nucleus and is usually catalyzed by an enzyme—RNA polymerase—using DNA as a template, a process known as transcription. Initiation of transcription begins with the binding of the enzyme to a promoter sequence in the DNA (usually found "upstream" of a gene). The DNA double helix is unwound by the helicase activity of the enzyme. The enzyme then progresses along the template strand in the 3' to 5' direction, synthesizing a complementary RNA molecule with elongation occurring in the 5' to 3' direction. The DNA sequence also dictates where termination of RNA synthesis will occur. Primary transcript RNAs are often modified by enzymes after transcription. For example, a poly(A) tail and a 5' cap are added to eukaryotic pre-mRNA and introns are removed by the spliceosome. There are also a number of RNA-dependent RNA polymerases that use RNA as their template for synthesis of a new strand of RNA. For instance, a number of RNA viruses (such as poliovirus) use this type of enzyme to replicate their genetic material. Also, RNA-dependent RNA polymerase is part of the RNA interference pathway in many organisms.
Sources: en.wikipedia.org
Diphtheria toxin is produced by virulent Corynebacterium diphtheriae that infect the mucosal membranes of the throat and nasal cavity causing a gray, thickened lining of the throat, sore throat, weakness, mild fever, swollen glands of the neck, and difficulty breathing. Diphtheria toxin is an ADP-ribosyltransferase that inhibits protein synthesis which causes the symptoms associated with the disease. Diphtheria used to be a leading cause of childhood death until the creation of a vaccine. The diphtheria vaccine contains a diphtheria toxoid, antigenically identical yet inactivated and non-toxic. When the toxoid is introduced to the body in a vaccine, an immune response is mounted without sequelae associated with the toxigenicity.
Actinium is found only in traces in uranium ores – one tonne of uranium in ore contains about 0.2 milligrams of 227Ac – and in thorium ores, which contain about 5 nanograms of 228Ac per one tonne of thorium. The actinium isotope 227Ac is a transient member of the uranium-actinium series decay chain, which begins with the parent isotope 235U (or 239Pu) and ends with the stable lead isotope 207Pb. The isotope 228Ac is a transient member of the thorium series decay chain, which begins with the parent isotope 232Th and ends with the stable lead isotope 208Pb. Another actinium isotope (225Ac) is transiently present in the neptunium series decay chain, beginning with 237Np (or 233U) and ending with thallium (205Tl) and near-stable bismuth (209Bi); even though all primordial 237Np has decayed away, it is continuously produced by neutron knock-out reactions on natural 238U. The low natural concentration and the close similarity of physical and chemical properties to those of lanthanum and other lanthanides, which are always abundant in actinium-bearing ores, render separation of actinium from the ore impractical. The most concentrated actinium sample prepared from raw material consisted of 7 micrograms of 227Ac in less than 0.1 milligrams of La2O3, and complete separation was never achieved. Instead, actinium is prepared, in milligram amounts, by the neutron irradiation of 226Ra in a nuclear reactor.
=== Plant breeding === Selective breeding of cannabis plants has expanded and diversified as commercial and therapeutic markets develop. Some growers in the US succeeded in lowering the proportion of CBD-to-THC to accommodate customers who preferred varietals that were more mind-altering due to the higher THC and lower CBD content. In the US, hemp is classified by the federal government as cannabis containing no more than 0.3% THC by dry weight. This classification was established in the 2018 Farm Bill and was refined to include hemp-sourced extracts, cannabinoids, and derivatives in the definition of hemp.
, in order to characterize the geometry. This correction factor, also often referred to as the geometric shape factor, is given by empirically determined series and accounts for the type and geometry of the crack or notch. We thus have:
== Medical uses == Cryoneuralysis has been used to relieve pain after thoracotomy, mastectomy, and knee or shoulder arthroplasty. Combined with ultrasound imaging, the procedure can be administered using a hand-held device in an office, and appears to provide an expedient, safe, and nonpharmacological option for treating various chronic pain conditions.
Sources: en.wikipedia.org
Notwithstanding, nutrition labels on Australian food products typically recommend the average daily energy intake of 8,800 kJ (2,100 kcal). The minimum food energy intake is also higher in cold environments. Increased mental activity has been linked with moderately increased brain energy consumption.
== Early life and career == Born in Afagnan in Lacs Prefecture at the Hospital of the Brothers of the Order of Saint-Jean-de-Dieu d'Afagnan, Faure Essozimna Gnassingbé is of Kabye descent and is one of Gnassingbé Eyadéma's many children; his mother is Séna Sabine Mensah. Gnassingbé received his secondary education in Lomé before studying in Paris at the Université Paris-Dauphine, where he received a degree in financial business management; he subsequently obtained a Master of Business Administration degree from George Washington University in the United States. He was elected to the National Assembly of Togo in the October 2002 parliamentary election as a Deputy for Blitta, and in the National Assembly he was coordinator of the commission in charge of privatization. On 29 July 2003, he was appointed as Minister of Equipment, Mines, Posts, and Telecommunications, serving in that position until becoming president in February 2005. Some in the opposition claimed that the amendment of the Constitution in December 2002, lowering the minimum age for the president from 45 years to 35 years, was intended to benefit Gnassingbé. His appointment to the government in July 2003 came after he had already been appearing with his father at official functions and contributed to speculation that he was intended as his father's successor.
Hydroponics is a type of horticulture and a subset of hydroculture which involves growing plants, usually crops or medicinal plants, without soil, by using water-based mineral nutrient solutions in an artificial environment. Terrestrial or aquatic plants may grow freely with their roots exposed to the nutritious liquid or the roots may be mechanically supported by an inert medium such as perlite, gravel, or other substrates. Despite inert media, roots can cause changes of the rhizosphere pH and root exudates can affect rhizosphere biology and physiological balance of the nutrient solution when secondary metabolites are produced in plants. Transgenic plants grown hydroponically allow the release of pharmaceutical proteins as part of the root exudate into the hydroponic medium. The nutrients used in hydroponic systems can come from many different organic or inorganic sources, including fish excrement, duck manure, purchased chemical fertilizers, or artificial standard or hybrid nutrient solutions. In contrast to field cultivation, plants are commonly grown hydroponically in a greenhouse or contained environment on inert media, adapted to the controlled environment agriculture (CEA) process. Plants commonly grown hydroponically include tomatoes, peppers, cucumbers, strawberries, lettuces, and cannabis, usually for commercial use, as well as Arabidopsis thaliana, which serves as a model organism in plant science and genetics. Hydroponics offers many advantages, notably a decrease in water usage in agriculture. To grow 1 kilogram (2.2 lb) of tomatoes using
Anger over the treatment of demonstrators following the death of Benno Ohnesorg and the attack on Rudi Dutschke, coupled with growing frustration over the lack of success in achieving their aims led to growing militance among students and their supporters. In May 1968, three young people set fire to two department stores in Frankfurt; they were brought to trial and made clear to the court that they regarded their action as a legitimate act in what they described as the "struggle against imperialism". The student movement began to split into different factions, ranging from the unattached liberals to the Maoists and supporters of direct action in every form—the anarchists. Several groups set as their objective the aim of radicalising the industrial workers; taking an example from activities in Italy of the Red Brigades (Brigate Rosse), many students went to work in the factories, but with little or no success. The most notorious of the underground groups was the Red Army Faction, which began by making bank raids to finance their activities and eventually went underground having killed a number of policemen, several bystanders and eventually two prominent West Germans, whom they had taken captive in order to force the release of prisoners sympathetic to their ideas. In the 1990s, attacks were still being committed under the name "RAF". The last action took place in 1993 and the group announced it was giving up its activities in 1998.
Medieval blast furnaces were about 10 feet (3.0 m) tall and made of fireproof brick; forced air was usually provided by hand-operated bellows. Modern blast furnaces have grown much bigger, with hearths fourteen meters in diameter that allow them to produce thousands of tons of iron each day, but essentially operate in much the same way as they did during medieval times. In 1709, Abraham Darby I established a coke-fired blast furnace to produce cast iron, replacing charcoal, although continuing to use blast furnaces. The ensuing availability of inexpensive iron was one of the factors leading to the Industrial Revolution. Toward the end of the 18th century, cast iron began to replace wrought iron for certain purposes, because it was cheaper. Carbon content in iron was not implicated as the reason for the differences in properties of wrought iron, cast iron, and steel until the 18th century. Since iron was becoming cheaper and more plentiful, it also became a major structural material following the building of the innovative first iron bridge in 1778. This bridge still stands today as a monument to the role iron played in the Industrial Revolution. Following this, iron was used in rails, boats, ships, aqueducts, and buildings, as well as in iron cylinders in steam engines. Railways have been central to the formation of modernity and ideas of progress and various languages refer to railways as iron road (e.g. French chemin de fer, German Eisenbahn, Turkish demiryolu, Russian железная дорога, Chinese, Japanese, and Korean 鐵道, Vietnamese đường sắt).
Sources: en.wikipedia.org
GSH is the reduced form of glutathione, with a free thiol group on cysteine. GSSG is the oxidized disulfide form, created when two GSH molecules become linked. The two forms exist together, and their balance is often reported as the GSH/GSSG ratio in laboratory studies.
Glutathione is synthesized inside cells from amino acids rather than being classified as an essential dietary nutrient. Dietary sources can provide glutathione or its precursors, but digestion and absorption alter what reaches tissues. Research continues on how dietary intake relates to cellular glutathione levels.
The liver has high glutathione concentrations and uses the compound in conjugation and antioxidant reactions. These reactions are relevant to the processing of drugs, pollutants, and normal metabolic byproducts. Studies often examine liver glutathione as a marker of oxidative stress or detoxification capacity.
Glutathione is a tripeptide of three amino acids: glutamate, cysteine, and glycine. The cysteine residue provides the sulfhydryl group that gives the molecule its reducing properties.