Carbohydrates Disaccharides Dr. Nikhat Siddiqi1
Contents Dr. Nikhat Siddiqi2 Lactose Maltose Cellobiose Sucrose
Dr. Nikhat Siddiqi3 Disaccharides are molecules composed of two monosaccharides that are linked by a glycosidic bonds. A glycosidic bond between two hexoses producing a disaccharide
Lactose Dr. Nikhat Siddiqi4 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).
Maltose Dr. Nikhat Siddiqi5 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.
Cellobiose Dr. Nikhat Siddiqi6 Degradation product of cellulose, contains two molecules of glucose linked by (1,4) glycosidic bond.
Sucrose Dr. Nikhat Siddiqi7 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.
Sucrose Dr. Nikhat Siddiqi8
Sucrose Dr. Nikhat Siddiqi9 Sucrose is not a reducing because both anomeric groups are involved in glycosidic linkage.
Dr. Nikhat Siddiqi10