DISACCHARIDES

A BRIEF PRESENTATION ON DISACCHARIDES.
NOTE- FONTS MAY APPEAR WEIRD BCOZ THE FONTS I USED DO NOT APPEAR IN THIS PPT.

1. DISACCHARIDES KANAV BHANOT Presentation on by Roll no. 05

2. CONTENTS DISACCHARIDES FORMATION CLASSIFICATION BIBLIOGRAPHY SUCROSE LACTOSE MALTOSE

3. When two monosaccharide are combined by glycosidic linkage, a disaccharide is formed. Therefore they yield two molecules of same or different monosaccharide on hydrolysis. General formula of Disaccharides : C n (H 2 O) n -1 The disaccharides just like monosaccharides are white crystalline, sweet solids. However , even though they are soluble in water, they are too large to pass through cell membranes. DISACCHARIDES

4. FORMATION Disaccharides are formed when two monosaccharides are joined together and a molecule of water is removed , a process known as dehydration reaction . For example; Milk sugar (lactose) is made from glucose and galactose . Sugar from sugar cane and sugar beet ( sucrose ) is made from glucose and fructose . Maltose , another notable disaccharide, is made up of two glucose molecules.

5. There are two different types of disaccharides: Reducing disaccharides , in which one monosaccharide, still has a free hemiacetal  unit. Non-reducing disaccharides , in which neither monosaccharide has a free hemiacetal unit . Example: i. SUCROSE Example : i. LACTOSE ii. MALTOSE CLASSIFICATION

6. sucrose STRUCTURE The glucose part had the aldehyde at carbon 1 , and the fructose part had the ketone group at carbon 2 . S ince the linkage is 1,2, neither group is free. Therefore, sucrose is not a reducing sugar .

7. INTRODUCTION The molecule is a disaccharide   derived from   glucose  and  fructose  with the  molecular formula C 12 H 22 O 11 . Sucrose is commonly known as  table sugar. It is a white, odourless, crystalline powder with a sweet taste. FUNCTIONS Used in syrup preparation, tablet manufacture, nutrient and demulcent . Sucrose is also used in preparation of dextran (a polysaccharide used as plasma substitute).

8. LACTOSE STRUCTURE It has a 1,4- glycosidic linkage , acts as a reducing sugar because both of the original aldehyde group were on carbon 1, and one of them is free to react.

9. INTRODUCTION Lactose is a disaccharide derived from the   condensation  of  Galactose  and  Glucose Lactose is commonly called Milk Sugar . It is Dextrorotatory Lactose requires you have an enzyme called lactase to digest the disaccharide. FUNCTIONS Widely used in food industry. Also used as filler in tablets.

10. MALTOSE STRUCTURE The aldehyde groups are at carbon 1 in each of the original glucose molecules. Since the linkage is 1,4 , one free aldehyde group remains. Therefore, maltose acts as a reducing sugar .

11. INTRODUCTION Maltose, is a disaccharide formed from two units of glucose . Maltose is commonly called Malt Sugar . It is produced commercially by hydrolysis of starch. FUNCTIONS Converted to glucose and used as an energy source for growing embryo in seed. Used in alcohol production.

12. BIBLIOGRAPHY The sources that enabled me to bring out this presentation to you all are : HARPER’S Illustrated Biochemistry Textbook of Biochemistry by VASUDEVAN Class Notes