Physical world and mathematics

Glutamic acid

Glutamic acid (L-glutamate) is a proteinogenic amino acid with an acidic side chain; as glutamate it is the brain's principal excitatory neurotransmitter and the source of umami taste.

Glutamine

Glutamine (symbol Gln) is a polar, proteinogenic amino acid and the amide of glutamic acid, the principal carrier of nitrogen in cells and the most abundant free amino acid.

Glutamine (amino acid)

Glutamine (L-glutamine, abbreviated Gln or Q) is a nonessential amino acid and the body's most abundant free amino acid, serving as its principal nitrogen carrier between organs.

Glutaraldehyde

Glutaraldehyde, also known as glutaral or pentanedial, is a five-carbon dialdehyde, a colorless oily liquid used as a high-level disinfectant, chemical sterilant, and protein cross-linking reagent.

Glutaric Acid

Glutaric acid, also called pentanedioic acid, is a five-carbon dicarboxylic acid with formula C5H8O4, produced as a by-product of adipic acid manufacture and used in polymers.

Glyceraldehyde, also called glyceral, is the simplest aldose, a sweet, colorless three-carbon sugar of formula C3H6O3 that acts as an intermediate in carbohydrate metabolism and sets the D/L convention for sugars.

Glycerol

Glycerol, also called glycerin or propane-1,2,3-triol, is a colorless, sweet-tasting, viscous alcohol that forms the backbone of fats and oils, used widely in foods, cosmetics, and pharmaceuticals.

Glycerol carbonate

Glycerol carbonate, also called glycerine carbonate, is a cyclic carbonate ester of glycerol made from biodiesel's glycerol byproduct and used as a green solvent, electrolyte component, and chemical intermediate.

Glycerol electrooxidation

Glycerol electrooxidation, usually written GEOR or GOR, is the electrocatalytic oxidation of glycerol at an electrode into value-added chemicals such as lactic acid and formate.

Glycerol oxidation

Glycerol oxidation is the family of chemical, electrochemical, and biological reactions that turn cheap byproduct glycerol from biodiesel into higher-value products such as glyceraldehyde, dihydroxyacetone, and glyceric acid.

Glycerol production

Glycerol production is the set of industrial processes that make glycerol, now overwhelmingly recovered from biodiesel and fat and oil processing rather than synthesized from propene.

Glycerolysis

Glycerolysis is the esterification reaction in which free fatty acids react with glycerol to form monoacylglycerols, diacylglycerols, and triacylglycerols, used to make emulsifiers and to lower the free fatty acid content of oils before biodiesel production.

Glycerophosphocholine

Glycerophosphocholine (GPC), also called alpha-GPC or, as a drug and supplement, choline alfoscerate, is a water-soluble breakdown product of phosphatidylcholine that serves as a choline donor and kidney osmolyte.

Glyceryl monostearate

Glyceryl monostearate, also known as monostearin or glycerol monostearate (GMS), is the glycerol ester of stearic acid, a waxy solid used as an emulsifier in foods, cosmetics, and pharmaceuticals.

Glycidol

Glycidol, also known as 2,3-epoxy-1-propanol, is a colorless, slightly viscous epoxide alcohol used industrially as a chemical intermediate, reactive diluent, and sterilant, and classified as probably carcinogenic to humans.

Glycidyl methacrylate

Glycidyl methacrylate (GMA) is a colorless liquid monomer carrying both a polymerizable methacrylate group and a reactive epoxide, produced at high volume for epoxy resins and dental sealants.

Glycine

Glycine (Gly, G), NH2CH2COOH, the simplest amino acid, first isolated by Braconnot in 1820. Non-essential; builds collagen, glutathione, purines, creatine, heme; inhibitory neurotransmitter and NMDA co-agonist; found in meteorites including Bennu.

Glycolic acid

Glycolic acid, also known as hydroxyacetic acid, is the smallest alpha hydroxy acid, made industrially from formaldehyde and carbon monoxide and used in skin care, peels, and biodegradable polymers.

Glycosidic bond

A glycosidic bond, also called a glycosidic linkage, is the covalent link that joins sugar units into disaccharides and polysaccharides, formed at the anomeric carbon.

Glycyrrhizin

Glycyrrhizin, also called glycyrrhizic acid or glycyrrhizinic acid, is a triterpenoid saponin glycoside from licorice root that is about 50 times sweeter than sugar and drives licorice's pharmacological effects.

Glyoxal

Glyoxal, also called ethanedial or ethane-1,2-dial, is the smallest dialdehyde, a yellow crystalline solid with formula OHC–CHO. It cross-links textiles and paper and forms in the atmosphere from isoprene oxidation.

Glyoxylic acid

Glyoxylic acid, also known as oxoacetic acid, is the simplest α-keto acid, a two-carbon molecule with both aldehyde and carboxylic acid groups, used in the pharmaceutical, food, and perfume industries.

GM Aur

GM Aur, or GM Aurigae, is a classical T Tauri star in the Taurus-Auriga star-forming region, about 155 parsecs from Earth, with a well-studied transitional protoplanetary disk.

GMTKN55

GMTKN55 is a benchmark database of about 1,500 chemically diverse reaction energies and barrier heights for main-group compounds, introduced by Lars Goerigk and Stefan Grimme's group in 2017 to assess DFT functionals.

GN-z11

GN-z11 is a luminous star-forming galaxy in the GOODS-North field, seen 430 million years after the Big Bang and announced in 2016 as the farthest galaxy then measured.

Gneiss

Gneiss is a coarse-grained, foliated metamorphic rock formed at high temperatures and pressures, with light bands of quartz and feldspar alternating with dark mica or hornblende bands.

Gnomon

A gnomon is the shadow-casting component of a sundial, typically a rod, plate, or raised edge, and the oldest astronomical instrument, in use since the second millennium B.C.

Sep 29, 2026

GNSS reflectometry

GNSS reflectometry (GNSS-R) is a bistatic remote sensing technique that retrieves ocean winds, sea surface height, soil moisture, and sea ice from reflected GPS and other navigation satellite signals.

GNU MPFR

GNU MPFR (Multiple Precision Floating-Point Reliable) is a portable C library for arbitrary-precision floating-point arithmetic, built on GNU MP and providing correctly rounded, reproducible results.