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Disaccharide
A disaccharide (also called a double sugar or ''biose'') is the sugar formed when two monosaccharides are joined by glycosidic linkage. Like monosaccharides, disaccharides are simple sugars soluble in water. Three common examples are sucrose, lactose, and maltose. Disaccharides are one of the four chemical groupings of carbohydrates (monosaccharides, disaccharides, oligosaccharides, and polysaccharides). The most common types of disaccharides—sucrose, lactose, and maltose—have 12 carbon atoms, with the general formula C12H22O11. The differences in these disaccharides are due to atomic arrangements within the molecule. The joining of monosaccharides into a double sugar happens by a condensation reaction, which involves the elimination of a water molecule from the functional groups only. Breaking apart a double sugar into its two monosaccharides is accomplished by hydrolysis with the help of a type of enzyme called a disaccharidase. As building the larger sugar ejects a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbohydrate
A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' may differ). This formula does not imply direct covalent bonding between hydrogen and oxygen atoms; for example, in , hydrogen is covalently bonded to carbon, not oxygen. While the 2:1 hydrogen-to-oxygen ratio is characteristic of many carbohydrates, exceptions exist. For instance, uronic acids and deoxy-sugars like fucose deviate from this precise stoichiometric definition. Conversely, some compounds conforming to this definition, such as formaldehyde and acetic acid, are not classified as carbohydrates. The term is predominantly used in biochemistry, functioning as a synonym for saccharide (), a group that includes sugars, starch, and cellulose. The saccharides are divided into four chemical groups: monosaccharides, disaccharides, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reducing Sugar
A reducing sugar is any sugar that is capable of acting as a reducing agent. In an alkaline solution, a reducing sugar forms some aldehyde or ketone, which allows it to act as a reducing agent, for example in Benedict's reagent. In such a reaction, the sugar becomes a carboxylic acid. All monosaccharides are reducing sugars, along with some disaccharides, some oligosaccharides, and some polysaccharides. The monosaccharides can be divided into two groups: the aldoses, which have an aldehyde group, and the ketoses, which have a ketone group. Ketoses must first tautomerize to aldoses before they can act as reducing sugars. The common dietary monosaccharides galactose, glucose and fructose are all reducing sugars. Disaccharides are formed from two monosaccharides and can be classified as either reducing or nonreducing. Nonreducing disaccharides like sucrose and trehalose have glycosidic bonds between their anomeric carbons and thus cannot convert to an open-chain form with an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sugar
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ..., fructose, and galactose. Compound sugars, also called disaccharides or double sugars, are molecules made of two bonded monosaccharides; common examples are sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (two molecules of glucose). White sugar is almost pure sucrose. In the body, compound sugars are hydrolysed into simple sugars. Longer chains of monosaccharides (>2) are not regarded as sugars and are called oligosaccharides or polysaccharides. Starch is a glucose polymer found in plants, the most abundant source of energy in human foo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sucrose Molecule
Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula . For human consumption, sucrose is extracted and refined from either sugarcane or sugar beet. Sugar mills – typically located in tropical regions near where sugarcane is grown – crush the cane and produce raw sugar which is shipped to other factories for refining into pure sucrose. Sugar beet factories are located in temperate climates where the beet is grown, and process the beets directly into refined sugar. The sugar-refining process involves washing the raw sugar crystals before dissolving them into a sugar syrup which is filtered and then passed over carbon to remove any residual colour. The sugar syrup is then concentrated by boiling under a vacuum and crystallized as the final purification process to produce crystals of pure sucrose that are clear, odorless, and sweet. Sugar is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sucrose
Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula . For human consumption, sucrose is extracted and refined from either sugarcane or sugar beet. Sugar mills – typically located in tropical regions near where sugarcane is grown – crush the cane and produce raw sugar which is shipped to other factories for refining into pure sucrose. Sugar beet factories are located in temperate climates where the beet is grown, and process the beets directly into refined sugar. The Sugar refinery, sugar-refining process involves washing the raw sugar crystals before dissolving them into a sugar syrup which is filtered and then passed over carbon to remove any residual colour. The sugar syrup is then concentrated by boiling under a vacuum and crystallized as the final purification process to produce crystals of pure sucrose that are clear, odorless, and sweet. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disaccharidase
Disaccharidases are glycoside hydrolases, enzymes that break down certain types of sugars called disaccharides into simpler sugars called monosaccharides. In the human body, disaccharidases are made mostly in an area of the small intestine's wall called the brush border, making them members of the group of "brush border enzymes". A genetic defect in one of these enzymes will cause a disaccharide intolerance, such as lactose intolerance or sucrose intolerance. Examples of disaccharidases * Lactase (breaks down lactose into glucose and galactose) * Maltase (breaks down maltose into 2 glucoses) * Sucrase (breaks down sucrose into glucose and fructose) * Trehalase (breaks down trehalose into 2 glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...s) For a thorough scien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of Biomolecule, biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g., sucrose being broken down into glucose and fructose), this is recognized as saccharification. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water. Types Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both the su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactose
Lactose is a disaccharide composed of galactose and glucose and has the molecular formula C12H22O11. Lactose makes up around 2–8% of milk (by mass). The name comes from (Genitive case, gen. ), the Latin word for milk, plus the suffix ''-ose'' used to name sugars. The compound is a white, water-soluble, non-Hygroscopy, hygroscopic solid with a mildly sweet taste. It is used in the food industry. Structure and reactions Lactose is a disaccharide composed of galactose and glucose, which form a β-1→4 Glycosidic bond, glycosidic linkage. Its systematic name is β-D-galactopyranosyl-(1→4)-D-glucose. The glucose can be in either the α-pyranose form or the β-pyranose form, whereas the galactose can have only the β-pyranose form: hence α-lactose and β-lactose refer to the anomeric form of the glucopyranose ring alone. Detection reactions for lactose are the Alfred Wöhlk, Wöhlk and William Fearon, Fearon tests. They can be used to detect the different lactose content o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monosaccharide
Monosaccharides (from Greek '' monos'': single, '' sacchar'': sugar), also called simple sugars, are the simplest forms of sugar and the most basic units (monomers) from which all carbohydrates are built. Chemically, monosaccharides are polyhydroxy aldehydes with the formula or polyhydroxy ketones with the formula with three or more carbon atoms. They are usually colorless, water- soluble, and crystalline organic solids. Contrary to their name (sugars), only some monosaccharides have a sweet taste. Most monosaccharides have the formula (CH2O)''x'' (though not all molecules with this formula are monosaccharides). Examples of monosaccharides include glucose (dextrose), fructose (levulose), and galactose. Monosaccharides are the building blocks of disaccharides (such as sucrose, lactose and maltose) and polysaccharides (such as cellulose and starch). The table sugar used in everyday vernacular is itself a disaccharide sucrose comprising one molecule of each of the two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maltase
Maltase is an informal name for a family of enzymes that catalyze the hydrolysis of disaccharide maltose into two simple sugars of glucose. Maltases are found in plants, bacteria, yeast, humans, and other vertebrates. Digestion of starch requires six intestinal enzymes. Two of these enzymes are luminal endo-glucosidases named alpha-amylases. The other four enzymes have been identified as different maltases, exo-glucosidases bound to the luminal surface of enterocytes. Two of these maltase activities were associated with sucrase-isomaltase (maltase Ib, maltase Ia). The other two maltases with no distinguishing characteristics were named maltase-glucoamylase (maltases II and III). The activities of these four maltases are also described as alpha-glucosidase because they all digest linear starch oligosaccharides to glucose. Structure Maltases are members of a group of intestinal enzymes called FamilyGH13 (Glycoside hydrolase family 13) that are responsible for breaking apart the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maltose
} Maltose ( or ), also known as maltobiose or malt sugar, is a disaccharide formed from two units of glucose joined with an α(1→4) bond. In the isomer isomaltose, the two glucose molecules are joined with an α(1→6) bond. Maltose is the two-unit member of the amylose homologous series, the key structural motif of starch. When beta-amylase breaks down starch, it removes two glucose units at a time, producing maltose. An example of this reaction is found in germinating seeds, which is why it was named after malt. Unlike sucrose, it is a reducing sugar. History Maltose was discovered by Augustin-Pierre Dubrunfaut, although this discovery was not widely accepted until it was confirmed in 1872 by Irish chemist and brewer Cornelius O'Sullivan. Its name comes from malt, combined with the suffix ' -ose' which is used in names of sugars. Structure and nomenclature Carbohydrates are generally divided into monosaccharides, oligosaccharides, and polysaccharides depending on th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sucrase
Sucrases are digestive enzymes that catalyze the hydrolysis of sucrose to its component monosaccharides, fructose and glucose. One form, sucrase-isomaltase, is secreted in the small intestine on the brush border. The enzyme invertase, which occurs more commonly in plants, fungi and bacteria, also hydrolyzes sucrose (and other fructosides) but by a different mechanism: it is a fructosidase, whereas sucrase is a glucosidase. Types * is sucrase-isomaltase * is sucrose alpha-glucosidase Physiology Sucrose intolerance (also known as congenital sucrase-isomaltase deficiency (CSID), genetic sucrase-isomaltase deficiency (GSID), or sucrase-isomaltase deficiency) occurs when sucrase is not being secreted in the small intestine. With sucrose intolerance, the result of consuming sucrose is excess gas production and often diarrhea and malabsorption. Lactose intolerance is a similar condition that reflects an individual's inability to hydrolyze the disaccharide lactose. Sucrase is secret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
