Starch Maltose

Classify the following carbohydrates into monosaccharides, disaccharides, or polysaccharides cellulose, glucose, lactose, starch, maltose, sucrose, chitin, and fructose. 

Fig. 81. Concentration dependence of the peak current for starch, maltose, and glucose measured by the equipment shown in Fig. 80.

Changes in optical rotation have been popular with those investigating glycoside hydrolysis since Wilhemy in 1850, using the newly invented polarimeter, demonstrated that hydrolysis of glycosides follows the first-order rate equation, k = 1/t log a/(a — x). Rate constants were then ob-tmned for the acid-catalyzed hydrolysis of salicin, - starch, maltose, lactose, methyl a- and /9-n-glucopyranoside, methyl a- and /S-n-galacto-pyranoside, - sucrose, and raffinose. ... 

Does not cleave P-1-4 links as occur in cellulose, a-1 -6 links at branches of starches, maltose... 

Action of sodium hydroxide. Boil about 0 2 g. of glucose with 5 of 10% NaOH solution the mixture turns yellow, then brown, and emits the odour of caramel. Fructose, maltose, lactose and soluble starch behave similarly sucrose and ordinary starch do not give colorations. 

Diastase (or amylase) liver, etc., malt starch (amylum) maltose and dextrin 6-0 (liver) 5-2 (malt)... 

Diastase or amylase is formed when malt is produced by the germination of barley grains. Malt is therefore a good source of the enzyme. Diastase is also secreted by the salivary glands (when it is known as ptyalin), and also by the pancreas. Its function is to hydrolysef starch to a mixture of maltose and dextrin ... 

Carbohydrates may be divided into monosaccharides, disaccharides and polysaccharides. The monosaccharides under certain conditions react as polyhydroxy-aldehydes or polyhydroxy-ketones two important representatives are glucose CjHjjO (an aldose) and fructose (laevulose) CgHuO, (a ketose). Upon hydrolysis di- and polysaccharides 3deld ultimately monosaccharides. Common disaccharides are sucrose, lactose and maltose (all of molecular formula C,2H2. 0,), whilst starch, dextrin and cellulose, (CjHjoOj), in which n > 4, are typical polysaccharides. 

Maltose obtained by the hydrolysis of starch and cellobiose by the hydrolysis of cellulose are isomenc disaccharides In both maltose and cellobiose two d glucopyra nose units are joined by a glycosidic bond between C 1 of one unit and C 4 of the other The two are diastereomers differing only m the stereochemistry at the anomeric carbon of the glycoside bond maltose is an a glycoside cellobiose is a (3 glycoside... 

Maltose (Section 25 14) A disacchande obtained from starch in which two glucose units are joined by an a(l 4) glyco sidic link... 

Acarbose is a nonabsorbable a-glucosidase inhibitor which blocks the digestion of starch, sucrose, and maltose. The digestion of complex carbohydrates is delayed and occurs throughout the small intestine rather than in the upper part of the jejunum. Absorption of glucose and other monosaccharides is not affected. Acarbose is adrninistered orally three times a day and chewed with the first mouthful of food. 

Com symps [8029-43 ] (glucose symp, starch symp) are concentrated solutions of partially hydrolyzed starch containing dextrose, maltose, and higher molecular weight saccharides. In the United States, com symps are produced from com starch by acid and enzyme processes. Other starch sources such as wheat, rice, potato, and tapioca are used elsewhere depending on avadabiHty. Symps are generally sold in the form of viscous Hquid products and vary in physical properties, eg, viscosity, humectancy, hygroscopicity, sweetness, and fermentabiHty. 

Quantitatively, the breakdown of starch to dextrin [9004-53-9] and maltose [69-79 ] is by far the most important. It takes place according to the following equations. 

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