A reducing sugar is any sugar that, in basic solution, forms some aldehyde or ketone. This allows the sugar to act as a reducing agent, for example in the Maillard reaction and Benedict's reaction. Reducing sugars include glucose, glyceraldehyde, lactose, arabinose and maltose. All monosaccharides which contain ketone groups are known as ketoses, and those which contain aldehyde groups are known as aldoses. Significantly, sucrose is not a reducing sugar. It is in fact known as a non-reducing sugar. An aldehyde. ... Ketone group A ketone (pronounced as key tone) is either the functional group characterized by a carbonyl group (O=C) linked to two other carbon atoms or a chemical compound that contains this functional group. ... A reducing agent (also called a reductant or reducer) is the element or a compound in a redox (reduction-oxidation) reaction (see electrochemistry) that reduces another species. ... The Maillard reaction is a chemical reaction between an amino acid and a reducing sugar, usually requiring the addition of heat. ... Benedicts Reagent (also called Benedicts solution or Benedicts test) is a reagent named after an American chemist, Stanley Rossiter Benedict. ... Glucose (Glc), a monosaccharide (or simple sugar), is an important carbohydrate in biology. ... Fischer projection of D-glyceraldehyde Glyceraldehyde is a triose monosaccharide with chemical formula C3H6O3. ... Lactose is a disaccharide that consists of β-D-galactose and β-D-glucose molecules bonded through a β1-4 glycosidic linkage. ... Fischer projection of L-arabinose The chemical structure of D-arabinofuranose Arabinose is an aldopentose — a monosaccharide containing five carbon atoms, and including an aldehyde (CHO) functional group. ... α-Maltose Maltose (also: malt sugar, di-glucose) is a disaccharide with the molecular formula C12H22O11. ... Ketone group A ketone (pronounced as key tone) is either the functional group characterized by a carbonyl group (O=C) linked to two other carbon atoms or a chemical compound that contains this functional group. ... A ketose is a sugar containing one ketone group per molecule. ... An aldehyde. ... Fischer projection of D-glyceraldehyde An aldose is a sugar containing one aldehyde group per molecule and having a chemical formula of the form C3nH6nO3n. ... Sucrose (common name: table sugar, also called saccharose) is a disaccharide (glucose + fructose) with the molecular formula C12H22O11. ... A reducing sugar is any sugar that, in basic solution, forms some aldehyde or ketone. ...

Benedict's reagent is used to determine if a reducing sugar is present. If it is a reducing sugar, the mixture will turn green/orange/red. Fehling's solution can also be used for the same purpose, as both contain copper (II) ions, which are reduced to a brick red precipitate of copper (I) oxide when the solution is heated. Benedicts Reagent (also called Benedicts solution or Benedicts test) is a reagent named after an American chemist, Stanley Rossiter Benedict. ... Fehlings solution is a solution used to deferentiate between aldehyde or ketone functional groups. ...

A reducing sugar occurs when its anomeric carbon is free. Since sugars occur in a chain as well as a ring structure, it is possible to have an equilibrium between these two forms. When the hemi-acetal or ketal hydroxylgroup is free, it is not locked, not linked to another (sugar)molecule, the aldehyde (or keto-) form (i.e. the chain-form) is available for reducing copper (II) ions. When a sugar is oxidized its carbonyl group (i.e. aldehyde or ketone group) is converted to a carboxyl group. It has been suggested that this article or section be merged with Anomeric carbon. ...