Carbohydrates

thumb|Sugars (clockwise from top-left): white refined, unrefined, brown sugar|brown, unprocessed cane sugar

thumb|class=skin-invert-image|upright=1.25|Lactose is a [[disaccharide found in animal milk. It consists of a molecule of D-galactose and a molecule of D-glucose bonded by beta-1-4 glycosidic linkage.]]

thumb|Structure of the amylose molecule thumb|Structure of the amylopectin molecule

thumb|400px|class=skin-invert-image|Summary of aerobic respirationGlycolysis is the metabolic pathway that converts glucose () into pyruvate and, in most organisms, occurs in the liquid part of cells (the cytosol). The free energy released in this process is used to form the high-energy molecules adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide (NADH). Glycolysis is a sequence of ten reactions catalyzed by enzymes. thumb|375x375px|Summary of the 10 reactions of the glycolysis pathway

Amylopectin is a water-insoluble polysaccharide and highly branched polymer of α-glucose units found in plants. It is one of the two components of starch, the other being amylose. thumb|Relation of amylopectin to starch granule|center Plants store starch within specialized organelles called amyloplasts. To generate energy, the plant hydrolyzes the starch, releasing the glucose subunits. Humans and other animals that eat plant foods also use amylase, an enzyme that assists in breaking down amylopectin, to initiate the hydrolysis of starch.

Lactulose is a non-absorbable sugar used in the treatment of constipation and hepatic encephalopathy. It is administered orally for constipation, and either orally or rectally for hepatic encephalopathy. It generally begins working after 8–12 hours, but may take up to 2 days to improve constipation.

thumb|A typical legume lectin monomer (lentil lectin), complexed with a sugar ([[glucose). The four sugar-binding loops are shown in different colours. The variable loop that confers monosaccharide specificity is shown in orange.]]

thumb|Crystalline trehalose dihydrate powder Trehalose is a sugar derived from two molecules of glucose. Trehalose is a disaccharide formed by a bond between two α-glucose units. It is found in nature as a disaccharide and also as a monomer in some polymers. Two other stereoisomers exist: α,β-trehalose, also called neotrehalose, and β,β-trehalose, also called isotrehalose. Neither of these alternate isomers has been isolated from living organisms, but isotrehalose has been found in starch hydroisolates. Some bacteria, fungi, plants and invertebrate animals synthesize trehalose as a source of e

covalent bond joining a sugar molecule to another group

Glycosylation is the reaction in which a carbohydrate (or 'glycan'), i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule (a glycosyl acceptor) in order to form a glycoconjugate. In biology (but not always in chemistry), glycosylation usually refers to an enzyme-catalysed reaction, whereas glycation (also 'non-enzymatic glycation' and 'non-enzymatic glycosylation') may refer to a non-enzymatic reaction.

projection formula in which the ring is drawn as if planar and the substituents points straight up or straight down perpendicular to the ring

In stereochemistry, mutarotation is the change in optical rotation of a chiral material in a solution due to a change in proportion of the two constituent anomers (i.e. the interconversion of their respective stereocenters) until equilibrium is reached. Cyclic sugars show mutarotation as α and β anomeric forms interconvert. The optical rotation of the solution depends on the optical rotation of each anomer and their ratio in the solution.

In carbohydrate chemistry, anomers () are specific types of stereoisomers found in sugars.

sugars that contain free OH group at the anomeric carbon atom

Glycation (non-enzymatic glycosylation) is the covalent attachment of a sugar to a protein, lipid or nucleic acid molecule. Typical sugars that participate in glycation are glucose, fructose, galactose, and their derivatives. Glycation is the non-enzymatic process responsible for many (e.g. micro and macrovascular) complications in diabetes mellitus and is implicated in other diseases and in aging.

class of enzymes

Methanediol, also known as formaldehyde monohydrate or methylene glycol, is an organic compound with chemical formula . It is the simplest geminal diol. In aqueous solutions it coexists with oligomers (short polymers). The compound is closely related and convertible to the industrially significant derivatives paraformaldehyde (), formaldehyde (), and 1,3,5-trioxane ().

thumb|right|250px|Glucosinolate structure; side group R varies. Glucosinolates are natural components of many pungent plants such as mustard, cabbage, and horseradish. The pungency of those plants is due to mustard oils produced from glucosinolates when the plant material is chewed, cut, or otherwise damaged. These natural chemicals most likely contribute to plant defence against pests and diseases, and impart a characteristic bitter flavor property to cruciferous vegetables.

thumb|Most glycosyltransferase enzymes form one of two folds: GT-A or GT-B Glycosyltransferases (GTFs, Gtfs) are enzymes (EC 2.4) that establish natural glycosidic linkages. They catalyze the transfer of saccharide moieties from an activated nucleotide sugar (also known as the "glycosyl donor") to a nucleophilic glycosyl acceptor molecule, the nucleophile of which can be oxygen- carbon-, nitrogen-, or sulfur-based.

chemical compound

FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) are short-chain carbohydrates that are poorly absorbed in the small intestine and ferment in the colon. They include short-chain oligosaccharide polymers of fructose (fructans) and galactooligosaccharides (stachyose, raffinose), disaccharides (lactose), monosaccharides (fructose), and sugar alcohols (polyols), such as sorbitol, mannitol, xylitol, and maltitol. Most FODMAPs are naturally present in food and the human diet, but the polyols may be added artificially in commercially prepared foods and beverages.

thumb|right|A segment of galactomannan showing mannose backbone (below) with a branching galactose unit (top) Galactomannans are polysaccharides consisting of a mannose backbone with galactose side groups, more specifically, a (1-4)-linked beta-D-mannopyranose backbone with branchpoints from their 6-positions linked to alpha-D-galactose, (i.e. 1-6-linked alpha-D-galactopyranose).

In molecular biology and biochemistry, glycoconjugates are a subfamily for carbohydrates where saccharides are covalently linked with proteins, peptides, lipids. Glycoconjugates are formed in processes termed glycosylation. Glycoconjugates are involved in cell–cell interaction, including cell–cell recognition; in cell–matrix interactions; and in detoxification processes.

Glucocerebroside (also called glucosylceramide) is any of the cerebrosides in which the monosaccharide head group is glucose.

thumb|right|200px|Ball-and-stick model of glucosazone

thumb|500px|Subunit of a typical mannan showing four 1,4-linked beta-D-mannose units, one with a galactose side chain. Mannans are polymers containing the sugar mannose as a principal component. They are a type of polysaccharide found in hemicellulose, a major source of biomass found in higher plants such as softwoods. These polymers also typically contain two other sugars, galactose and glucose. They are often branched (unlike cellulose).

chemical reaction involving the formation of sugars from formaldehyde

stereoelectronic effect, tendency of heteroatomic substituents adjacent to a heteroatom within a cyclohexane ring to prefer the axial orientation instead of the less hindered equatorial orientation that would be expected from steric considerations

thumb|Beta-amylase, a type of glucosidase Glucosidases are the glycoside hydrolase enzymes categorized under the EC number 3.2.1.

enzyme class, includes alll types of glycogen/starch synthases

Galactan (galactosan) is a polysaccharide consisting of polymerized galactose. In general, galactans in natural sources contain a core of galactose units connected by α(1→3) or α(1→6), with structures containing other monosaccharides as side-chains.

reaction in organic chemistry

thumb|right|100px|Glucal, the glycal formed from glucose Glycal is a name for cyclic enol ether derivatives of sugars having a double bond between carbon atoms 1 and 2 of the ring. The term "glycal" should not be used for an unsaturated sugar that has a double bond in any position other than between carbon atoms 1 and 2.