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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 wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbohydrate
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or may not be different from ''n''), which does not mean the H has covalent bonds with O (for example with , H has a covalent bond with C but not with O). However, not all carbohydrates conform to this precise stoichiometric definition (e.g., uronic acids, deoxy-sugars such as fucose), nor are all chemicals that do conform to this definition automatically classified as carbohydrates (e.g. formaldehyde and acetic acid). The term is most common in biochemistry, where it is a synonym of saccharide (), a group that includes sugars, starch, and cellulose. The saccharides are divided into four chemical groups: monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Monosaccharides and disaccharides, the smallest (lower mo ... [...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. Suga ... [...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-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. Su ... [...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 a ... [...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-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. Su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycosidic Linkage
A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate. A glycosidic bond is formed between the hemiacetal or hemiketal group of a saccharide (or a molecule derived from a saccharide) and the hydroxyl group of some compound such as an alcohol. A substance containing a glycosidic bond is a glycoside. The term 'glycoside' is now extended to also cover compounds with bonds formed between hemiacetal (or hemiketal) groups of sugars and several chemical groups other than hydroxyls, such as -SR (thioglycosides), -SeR (selenoglycosides), -NR1R2 (N-glycosides), or even -CR1R2R3 (C-glycosides). Particularly in naturally occurring glycosides, the compound ROH from which the carbohydrate residue has been removed is often termed the aglycone, and the carbohydrate residue itself is sometimes referred to as the 'glycone'. S-, N-, C-, and O-glycosidic bonds Glycosidic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactose
Lactose is a disaccharide sugar synthesized by galactose and glucose subunits and has the molecular formula C12H22O11. Lactose makes up around 2–8% of milk (by mass). The name comes from ' (gen. '), the Latin word for milk, plus the suffix ''-ose'' used to name sugars. The compound is a white, water-soluble, non-hygroscopic solid with a mildly sweet taste. It is used in the food industry. Structure and reactions Lactose is a disaccharide derived from the condensation of galactose and glucose, which form a β-1→4 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 only have 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 Woehlk- and Fearon's test. Both can be easily used in school experiments to visualise the different lactose conte ... [...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 the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trehalose
Trehalose (from Turkish '' tıgala'' – a sugar derived from insect cocoons + -ose) is a sugar consisting of two molecules of glucose. It is also known as mycose or tremalose. Some bacteria, fungi, plants and invertebrate animals synthesize it as a source of energy, and to survive freezing and lack of water. Extracting trehalose was once a difficult and costly process, but around 2000, the Hayashibara company (Okayama, Japan) discovered an inexpensive extraction technology from starch. Trehalose has high water retention capabilities, and is used in food, cosmetics and as a drug. A procedure developed in 2017 using trehalose allows sperm storage at room temperatures. Structure 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 isomers exist, α,β-trehalose, otherwise known as neotrehalose, and β,β-trehalose (also referred to as isotrehalose). Neotrehalose has n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycosidic Bond
A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate. A glycosidic bond is formed between the hemiacetal or hemiketal group of a saccharide (or a molecule derived from a saccharide) and the hydroxyl group of some compound such as an alcohol. A substance containing a glycosidic bond is a glycoside. The term 'glycoside' is now extended to also cover compounds with bonds formed between hemiacetal (or hemiketal) groups of sugars and several chemical groups other than hydroxyls, such as -SR (thioglycosides), -SeR (selenoglycosides), -NR1R2 (N-glycosides), or even -CR1R2R3 (C-glycosides). Particularly in naturally occurring glycosides, the compound ROH from which the carbohydrate residue has been removed is often termed the aglycone, and the carbohydrate residue itself is sometimes referred to as the 'glycone'. S-, N-, C-, and O-glycosidic bonds Glycosidic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellobiose
Cellobiose is a disaccharide with the formula (C6H7(OH)4O)2O. It is classified as a reducing sugar. In terms of its chemical structure, it is derived from the condensation of a pair of β-glucose molecules forming a β(1→4) bond. It can be hydrolyzed to glucose enzymatically or with acid. Cellobiose has eight free alcohol (OH) groups, one acetal linkage and one hemiacetal linkage, which give rise to strong inter- and intramolecular hydrogen bonds. It is a white solid. It can be obtained by enzymatic or acidic hydrolysis of cellulose and cellulose-rich materials such as cotton, jute, or paper. Cellobiose can be used as an indicator carbohydrate for Crohn's disease and malabsorption syndrome. Treatment of cellulose with acetic anhydride and sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen ... [...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, 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 a refined form of 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 food. Some other chemical substances, such as glycerol and sugar alcohols, may have a sweet taste, but are not classified as sugar. Sugars are found in the tissues of most plants. Honey and fruits are abundant natural sources of simple su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
