Difference between revisions of "Maltose" - New World Encyclopedia
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| − | ! {{chembox header}}| '''{{{name|{{PAGENAME}}}}}'''<ref>''Merck Index | + | ! {{chembox header}}| '''{{{name|{{PAGENAME}}}}}'''<ref>O'Neil, M. J. 2001. ''The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, N.J.: Merck. '''5595'''. ISBN 0911910131.</ref> |
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| align="center" colspan="2" bgcolor="#ffffff" | [[Image:Maltose structure.svg|199px]] | | align="center" colspan="2" bgcolor="#ffffff" | [[Image:Maltose structure.svg|199px]] | ||
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| [[Density]] | | [[Density]] | ||
| − | | {{{density|1.54}}} g/cm<sup>3</sup> <ref name="MSDS">[http://www.bme.utexas.edu/ugrad/UGLab/resources/MSDS/maltose.pdf MSDS for maltose monohydrate]</ref> | + | | {{{density|1.54}}} g/cm<sup>3</sup> <ref name="MSDS">Biological Engineering Undergraduate Lab, University of Texas. 2002. [http://www.bme.utexas.edu/ugrad/UGLab/resources/MSDS/maltose.pdf Material safety data sheet (MSDS) for D-(+)-maltose monohydrate]. ''University of Texas as Austin''. Retrieved June 30, 2007.</ref> |
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| Solubility | | Solubility | ||
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| − | '''Maltose''', or '''malt sugar''', is a [[disaccharide]] formed from two units of [[glucose]] joined with an α(1→4) linkage. | + | '''Maltose''', or '''malt sugar''', is a [[disaccharide]] formed from two units of [[glucose]] joined with an α(1→4) linkage. Maltose is not common in food, but can be formed from the digestion of [[starch]], and malt, the juice of [[barley]] and other grains is heavy, in maltose. Maltose is a member of an important biochemical series of [[glucose]] chains. As disaccharids, maltose, [[sucrose]], and [[lactose]] have the same chemical formula, (C<sub>12</sub>H<sub>22</sub>O<sub>11</sub>; however, they both differs in structure (see [[#structure|structure]] below). |
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| − | Maltose can be broken down into two glucose molecules by [[hydrolysis]]. In living [[organism]]s, the | + | Maltose can be produced from starch by hydrolysis in the presence of the enzyme diastase. It can be broken down into two glucose molecules by [[hydrolysis]]. In living [[organism]]s, the enzyme [[maltase]] can achieve this very rapidly. In the laboratory, heating with a strong acid for several minutes will produce the same result. |
| − | + | Maltose is important in the fermentation of [[alcohol]] as starch is converted to carbohydrates and is readily broken down into glucose molecules with the maltase present in [[yeast]]. The production of maltose in [[germinating]] [[cereals]], such as [[barley]], is an important part of the [[brewing]] process. When barley is [[malt]]ed, it is brought into a condition in which the concentration of maltose has been maximized. Metabolism of maltose by yeast during fermentation then leads to the production of [[ethanol]] and [[carbon dioxide]]. | |
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| − | The production of maltose in [[germinating]] [[cereals]], such as [[barley]], is an important part of the [[brewing]] process. When barley is [[malt]]ed, it is brought into a condition in which the concentration of maltose has been maximized. Metabolism of maltose by yeast during fermentation then leads to the production of [[ethanol]] and [[carbon dioxide]]. | ||
==Structure== | ==Structure== | ||
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The addition of another glucose unit yields [[maltotriose]]. Further additions will produce [[dextrin]]s, also called maltodextrins, and eventually [starch]. | The addition of another glucose unit yields [[maltotriose]]. Further additions will produce [[dextrin]]s, also called maltodextrins, and eventually [starch]. | ||
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| + | As disaccharids, maltose, [[sucrose]], and [[lactose]] have the same chemical formula, (C<sub>12</sub>H<sub>22</sub>O<sub>11</sub>; however, they both differs in structure. Whereas maltose links two glucose units by an α(1→4) [[glycosidic]] linkage (joins a carbohydrate molecule to an alcohol, which may be another carbohydrate), lactose involves glucose and [galactose]] bonded through a β1-4 glycosidic linkage, and sucrose consists of two [[glucose]] and [[fructose]] joined by a glycosidic bond between carbon atom 1 of the glucose unit and carbon atom 2 of the fructose unit. | ||
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==Function== | ==Function== | ||
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* [[Maltase]] | * [[Maltase]] | ||
* [[Iso maltase]] | * [[Iso maltase]] | ||
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| + | ==Notes== | ||
| + | <references/> | ||
==References== | ==References== | ||
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==External links== | ==External links== | ||
Revision as of 13:58, 30 June 2007
| Maltose[1] | |
|---|---|
| |
| Chemical name | 4-O-α-D-Glucopyranosyl-D-glucose |
| Other names | Maltose Malt sugar Maltobiose |
| Chemical formula | C12H22O11 |
| Molecular mass | 342.1162 g/mol |
| CAS number | [69-79-4] |
| Density | 1.54 g/cm3 [2] |
| Solubility | 1.080 g/ml (20 °C) in water[2] |
| Melting point | 102-103 °C (monohydrate) |
| Boiling point | N/A |
| SMILES | OC[C@H]1O[C@H](O[C@H ]2[C@H](O)[C@@H](O)C(O)O [C@@H]2CO)[C@H](O)[C@@H](O)[C@@H]1O |
| Disclaimer and references | |
Maltose, or malt sugar, is a disaccharide formed from two units of glucose joined with an α(1→4) linkage. Maltose is not common in food, but can be formed from the digestion of starch, and malt, the juice of barley and other grains is heavy, in maltose. Maltose is a member of an important biochemical series of glucose chains. As disaccharids, maltose, sucrose, and lactose have the same chemical formula, (C12H22O11; however, they both differs in structure (see structure below).
Maltose can be produced from starch by hydrolysis in the presence of the enzyme diastase. It can be broken down into two glucose molecules by hydrolysis. In living organisms, the enzyme maltase can achieve this very rapidly. In the laboratory, heating with a strong acid for several minutes will produce the same result.
Maltose is important in the fermentation of alcohol as starch is converted to carbohydrates and is readily broken down into glucose molecules with the maltase present in yeast. The production of maltose in germinating cereals, such as barley, is an important part of the brewing process. When barley is malted, it is brought into a condition in which the concentration of maltose has been maximized. Metabolism of maltose by yeast during fermentation then leads to the production of ethanol and carbon dioxide.
Structure
Carbohydrates are a class of biological molecules that contain primarily carbon (C) atoms flanked by hydrogen (H) atoms and hydroxyl (OH) groups (H-C-OH).
The single most common monosaccharide is the aldohexose D-glucose, represented by the formula C6H12O6. The carbons of glucose are numbered beginning with the more oxidized end of the molecule, the carbonyl group.
In addition to the free monosaccharide, glucose also occurs in disaccharides, which consist of two monosaccharide units linked covalently. Each disaccharide is formed by a condensation reaction in which there is a loss of hydrogen (H) from one molecule and a hydroxyl group (OH) from the other. Glycosidic bonds form between carbon 1 of the first glucose molecule and carbon 4 of the second glucose molecule. The resulting glycosidic bond is the characteristic linkage between sugars. Three common disaccharides are shown in the figure. Maltose (malt sugar) is made up of two glucose units linked together. Lactose (milk sugar) consists of a glucose linked to a galactose. Sucrose (common table sugar) has a glucose linked to a fructose.
Although the disaccharide maltose contains two glucose molecules, it is not the only disaccharide that can be made from two glucoses. When glucose molecules form a glycosidic bond, the linkage will be one of two types, α or β, depending on whether the molecule that bonds its carbon 1 is an α-glucose or β-glucose. An α-linkage with carbon 4 of a second glucose molecule results in maltose, whereas a β-linkage results in cellobiose. Although maltose and cellobiose are disaccharide isomers, both having the formula C12H22O11, they are different compounds with different properties. For example, maltose can be hydrolyzed to its monosaccharides in the human body where as cellobiose cannot. Some organisms have the capacity to break down cellobiose.
Maltose consists of two glucose molecules joined by an alpha glycosidic bond.
The addition of another glucose unit yields maltotriose. Further additions will produce dextrins, also called maltodextrins, and eventually [starch].
As disaccharids, maltose, sucrose, and lactose have the same chemical formula, (C12H22O11; however, they both differs in structure. Whereas maltose links two glucose units by an α(1→4) glycosidic linkage (joins a carbohydrate molecule to an alcohol, which may be another carbohydrate), lactose involves glucose and [galactose]] bonded through a β1-4 glycosidic linkage, and sucrose consists of two glucose and fructose joined by a glycosidic bond between carbon atom 1 of the glucose unit and carbon atom 2 of the fructose unit.
Function
Maltose is an interesting compound because of its use in alcohol production. Through a process called fermentation, glucose, maltose and other sugars are converted to ethanol by yeast cells in the absence of oxygen. Through an analogous process, muscle cells convert glucose into lactic acid to obtain energy while the body operates under anaerobic conditions. Although maltose is uncommon in nature, it can be formed through the breakdown of starch by the enzymes of the mouth.
See also
- Sugar
- Disaccharide
- Glucose
- Fructose
- Maltase
- Iso maltase
Notes
- ↑ O'Neil, M. J. 2001. The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, N.J.: Merck. 5595. ISBN 0911910131.
- ↑ 2.0 2.1 Biological Engineering Undergraduate Lab, University of Texas. 2002. Material safety data sheet (MSDS) for D-(+)-maltose monohydrate. University of Texas as Austin. Retrieved June 30, 2007.
ReferencesISBN links support NWE through referral fees
External links
Template:ChemicalSources
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