Everything below concerns thiol. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-11-25. Where a claim depends on a specific study, the study is described rather than over-claimed.
Cells synthesize glutathione through two ATP-dependent steps: glutamate-cysteine ligase joins glutamate and cysteine, and glutathione synthetase adds glycine to form the complete tripeptide. Breakdown occurs through gamma-glutamyl transpeptidase and subsequent peptidase reactions, forming the gamma-glutamyl cycle. Within cells, glutathione also forms a disulfide-linked dimer called GSSG when two GSH molecules react. The balance between GSH and GSSG is widely used as an indicator of oxidative conditions, although the ratio can vary by compartment and tissue.
Glutathione supports several cellular processes beyond direct antioxidant action. It serves as a cofactor for glutathione peroxidase and glutathione S-transferase enzymes, which reduce peroxides and conjugate electrophiles, respectively. The molecule also acts as a reservoir of cysteine, an amino acid that can limit protein synthesis and redox signaling. In human nutrition, oral glutathione is sold as a supplement, but how much intact glutathione reaches tissues after ingestion remains an active research question. Clinical claims about supplementation are not uniformly supported by controlled trials.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C10H17N3O6S | Reduced form; oxidized dimer is C20H32N6O12S2 |
| Molar mass | 307.32 g/mol | For reduced glutathione (GSH) |
| Appearance | White crystalline powder | Typical laboratory and supplement-grade material |
| Solubility | Soluble in water | Poorly soluble in ethanol and other nonpolar solvents |
| Typical storage | -20 C, desiccated, protected from light | Reduced form can oxidize in solution |
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. It occurs in nearly all living cells, with highest concentrations in liver, kidney, and red blood cells, and exists in reduced (GSH) and oxidized disulfide (GSSG) forms. The cysteine thiol group enables reversible oxidation and reduction reactions. This property makes glutathione a central participant in cellular redox balance. The balance between these forms is often used as an indicator of oxidative stress.
Glutathione synthesis proceeds in two ATP-dependent steps catalyzed by glutamate-cysteine ligase and glutathione synthetase. The first step joins glutamate and cysteine to form gamma-glutamylcysteine and is generally rate-limiting. The second step adds glycine to complete the tripeptide. Cysteine availability, feedback inhibition by glutathione, and oxidative conditions influence flux through this pathway. The pathway is conserved across many organisms, and degradation by gamma-glutamyl transpeptidase and related peptidases recycles amino acids for new synthesis.
Within cells, glutathione serves as a cofactor for glutathione peroxidases and glutathione S-transferases. These enzymes reduce hydrogen peroxide and organic peroxides or conjugate electrophilic compounds to the thiol group. The resulting conjugates can be exported and processed through mercapturic acid pathways. Glutathione also contributes to protein thiol homeostasis and to recycling of other antioxidants such as ascorbate. Its precise roles vary by tissue, and many regulatory effects observed in laboratory systems remain difficult to quantify in whole organisms.
In cells, glutathione exists mainly in a reduced form called GSH. When two GSH molecules react, they form oxidized glutathione, or GSSG, which contains a disulfide bond. The ratio of GSH to GSSG is often used as an indicator of oxidative stress. Enzymes such as glutathione peroxidase and glutathione reductase help cycle the molecule between these two states. This cycling supports antioxidant defense, detoxification of reactive molecules, and regulation of certain signaling pathways.
Glutathione is present in most tissues, with especially high concentrations in the liver. It also serves as a cofactor for some enzymes and helps transport amino acids across cell membranes. In plants and microorganisms, glutathione contributes to stress responses and metal handling. The molecule is synthesized in two ATP-dependent steps, first producing gamma-glutamylcysteine and then adding glycine. Because cysteine availability often limits synthesis, dietary and metabolic factors can influence glutathione levels. Research continues to examine how these levels relate to health and disease.
August Wilhelm joined the conservative nationalist veterans group Der Stahlhelm (English: "The Steel helmet"). In the following years he had increasing contact with the NSDAP. He joined the Nazi Party on 1 April 1930, whereupon he received the low membership number 24, for symbolic reasons. In November 1931, he was accepted into the paramilitary Sturmabteilung (SA) with the rank of Standartenführer. His involvement with the NSDAP and his adoration of Adolf Hitler made August Wilhelm often the subject of mockery by the left-wing press (who gave him the nickname Braunhemdchen Auwi, or "Auwi the Little Brown Shirt"), politicians (French Ambassador André François-Poncet called him Hanswurst "Hans the Brown Sausage") and from the National Socialists themselves (Joseph Goebbels referred to him as a "good-natured but slightly gormless boy"). As a representative of the erstwhile Hohenzollern dynasty, August Wilhelm was deliberately used by the party to gain votes in elections: he was elected as its lead candidate for the Landtag of Prussia in April 1932, and retained his seat until the Landtag's dissolution in October 1933. At the same time, he was appointed an election speaker alongside Hitler, whom he accompanied on flights across Germany. Through his appearances at the party's mass rallies, he addressed himself to sections of the population that were lukewarm towards National Socialism and convinced them "that Hitler was not a threat, but a benefactor of the German people and the German Empire".
Eumelanin (lit. 'true melanin') has two forms linked to 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA). DHI-derived eumelanin is dark brown or black and insoluble, and DHICA -derived eumelanin is lighter and soluble in alkali. Both eumelanins arise from the oxidation of tyrosine in specialized organelles called melanosomes. This reaction is catalyzed by the enzyme tyrosinase. The initial product, dopaquinone can transform into either 5,6-dihydroxyindole (DHI) or 5,6-dihydroxyindole-2-carboxylic acid (DHICA). DHI and DHICA are oxidized and then polymerize to form the two eumelanins. In natural conditions, DHI and DHICA often co-polymerize, resulting in a range of eumelanin polymers. These polymers contribute to the variety of melanin components in human skin and hair, ranging from light yellow/red pheomelanin to light brown DHICA-enriched eumelanin and dark brown or black DHI-enriched eumelanin. These final polymers differ in solubility and color. Analysis of highly pigmented (Fitzpatrick type V and VI) skin finds that DHI-eumelanin comprises the largest portion, approximately 60–70%, followed by DHICA-eumelanin at 25–35%, and pheomelanin only 2–8%. Notably, while an enrichment of DHI-eumelanin occurs in during sun tanning, it is accompanied by a decrease in DHICA-eumelanin and pheomelanin. A small amount of black eumelanin in the absence of other pigments causes grey hair. A small amount of eumelanin in the absence of other pigments causes blond hair. Eumelanin is present in the skin and hair, etc.
Italian merchants, particularly the Venetians, Genoese, and Pisans, took control of international trade, thus reducing the influence of native merchants. The political system grew increasingly extractive and authoritarian, contributing to the empire's collapse in 1204. The fall of Constantinople during the Fourth Crusade in 1204 destroyed centuries of its wealth. Large landholdings were confiscated, and the empire fragmented into smaller rump states ruled by competing factions, making governance inefficient and increasing the costs of doing business. The state gradually lost control over trade practices, price regulations, the outflow of precious metals, and possibly even the minting of coins. Italian merchants further dominated trade as the events of 1204 opened the Black Sea to Western merchants, permanently altering the empire's fortunes. Farmers and manufacturers increasingly produced goods for local use and were affected by the insecurity of constant warfare. Despite these challenges, the empire's mixed economy (characterised by state interventions, public works, and market liberalisation) remained a model of medieval economic adaptability, even as it deteriorated under external pressures.
Sources: en.wikipedia.org
The method for removal of thiocarbonyl containing end groups includes reacting the polymers containing the end-groups with en excess of radicals which add to the reactive C=S bond of the end group forming an intermediate radical (shown below). The remaining radical on the polymer chain can be hydrogenated by what is referred to as a trapping group and terminate; this results in a polymer that is free of the end groups at the α and ω positions.
== Applications == To date, PAMPA models have been developed that exhibit a high degree of correlation with permeation across a variety of barriers, including Caco-2 cultures, the gastrointestinal tract, blood–brain barrier and skin. The donor and/or acceptor compartments may contain solubilizing agents, or additives that bind the drugs as they permeate. To improve the in vitro - in vivo correlation and performance of the PAMPA method, the lipid, pH and chemical composition of the system is often designed with biomimetic considerations in mind. Although active transport is not modeled by the artificial PAMPA membrane, up to 95% of known drugs are absorbed by passive transport. Some experts support a lower figure, so the amount is open to some interpretation. Microtiter plates with 96 wells can be used for the assay which increases the speed and lowers the per sample cost.
In 2005 MeMe Roth began an obesity campaign that led to several appearances in American mainstream media. Programs such as Eat Smart, Move More, Weigh Less, developed in 2007 by writing teams from North Carolina State University and North Carolina Division of Public Health, and now available beyond North Carolina, aim to combat obesity by a combination of healthy eating and increased exercise. In 2008, the state of Pennsylvania enacted a law, the "School Nutrition Policy Initiative," aimed at the elementary level. These "interventions included removing all sodas, sweetened drinks, and unhealthy snack foods from selected schools, 'social marketing' to encourage the consumption of nutritious foods and outreach to parents." The results were a "50 percent drop in incidence of obesity and overweight", as opposed to those individuals who were not part of the study. In the past decade, there have been school-based programs that target the prevention and management of childhood obesity. There is evidence that long term school-based programs have been effective in reducing the prevalence of childhood obesity. For two years, Duke University psychology and global health professor Gary Bennett and eight colleagues followed 365 obese patients who had already developed hypertension. They found that regular medical feedback, self-monitoring, and a set of personalized goals can help obese patients in a primary care setting lose weight and keep it off. Major U.S.
Sources: en.wikipedia.org
==== Bones ==== Local osteoporosis occurs in RA around the inflamed joints. It is postulated to be partially caused by inflammatory cytokines. More general osteoporosis is probably contributed to by immobility, systemic cytokine effects, local cytokine release in bone marrow, and corticosteroid therapy.
=== Temperature === Conversion of both CO and CO2 to CH4 starts at a catalyst temperature below 300°C, but the conversion is incomplete and peak tailing is evident. At around 340°C, conversion is complete, as indicated by area measurements, but some tailing limits the peak height. At 360-380°C, tailing is eliminated and there is little change in peak height up to 400°C. Operating temperatures for various methanizers range from 350-400°C. Although carbonization of CO has been reported at temperatures above 350°, it is rather a rare phenomenon.
In 1548, the house steward of Cosimo de' Medici, the grand duke of Tuscany, wrote to the Medici private secretary informing him that the basket of tomatoes sent from the grand duke's Florentine estate at Torre del Gallo "had arrived safely". Tomatoes were grown mainly as ornamentals early on after they arrived in Italy. For example, the Florentine aristocrat Giovanvettorio Soderini wrote how they "were to be sought only for their beauty", and were grown only in gardens or flower beds. The tomato's ability to mutate and create new and different varieties helped contribute to its success and spread throughout Italy. However, in areas where the climate supported growing tomatoes, their habit of growing close to the ground suggested low status. They were not adopted as a staple of the peasant population because they were not as filling as other crops. Additionally, both toxic and inedible varieties discouraged many people from attempting to consume or prepare any other varieties. In certain areas of Italy, such as Florence, the fruit was used solely as a tabletop decoration until it was incorporated into the local cuisine in the late 17th or early 18th century. The earliest discovered cookbook with tomato recipes was published in Naples in 1692, though the author had apparently obtained these recipes from Spanish sources. Varieties were developed over the following centuries for drying, for sauce, for pizzas, and for long-term storage. These varieties are usually known for their place of origin as much as by a variety name.
If arterial/venous is not specified for an acid–base or blood gas value, then it generally refers to arterial, and not venous which otherwise is standard for other blood tests. Acid–base and blood gases are among the few blood constituents that exhibit substantial difference between arterial and venous values. Still, pH, bicarbonate and base excess show a high level of inter-method reliability between arterial and venous tests, so arterial and venous values are roughly equivalent for these.
Sources: en.wikipedia.org
It is a tripeptide of glutamic acid, cysteine, and glycine. The linkage between glutamate and cysteine uses the gamma-carboxyl group, which is unusual for peptides.
GSH is the reduced form with a free thiol group. GSSG is the oxidized dimer formed when two GSH molecules join by a disulfide bond.
It is synthesized inside cells and is not classified as an essential dietary nutrient for most people. Dietary and supplemental sources are studied, but direct requirements are not established in the same way as for vitamins.
Glutathione is a sulfur-containing tripeptide made from glutamate, cysteine, and glycine. It is found in most cells and participates in redox balance and detoxification reactions.