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Carbohydrates

Disaccharides

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Contents Lactose Maltose Cellobiose Sucrose

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Disaccharides are molecules composed of two monosaccharides that are linked by a glycosidic bonds.

A glycosidic bond between two hexoses producing a disaccharide

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Lactose Found in milk. Composed of one

galactose linked through the hydroxyl group on carbon 1 in a beta – glycosidc linkage to the hydroxyl group of carbon 4 of a molecule of glucose ( 1,4).

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Maltose Also known as malt

sugar. Intermediate product

of starch hydrolysis and does not exist free in nature.

Disacharide with (1,4) glycosidic bond between two glucose residues.

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Cellobiose Degradation product

of cellulose, contains two molecules of glucose linked by (1,4) glycosidic bond.

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Sucrose Table sugar. Transportable source of energy in plants. Contains both -D-glucose and -D-fructose

residues. The two monosaccharides are linked through

glycosidic bond btween both anomeric carbons.

Neither ring can revert to open-chain form, it is non reducing sugar.

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Sucrose

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Sucrose Sucrose is not a reducing because both

anomeric groups are involved in glycosidic linkage.

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