DISACCHARIDES (REDUCING & NON- REDUCING SUGARS).pptx

MALTOSE, SUCROSE, LACTOSE, CELLOBIOSE, TREHALOSE

1. disaccharides DR. v. manon mani Assistant professor

2. Biological molecules Living Cells Trichloroacetic acid Acid insoluble pool (Molecule have molecular wt. more than 10000 Daltons) Acid soluble pool (Molecule have molecular wt. 18 to 1000 Daltons)

3. Biological molecules Molecular Weight Macromolecules (Above 10000) Micromolecules (Between 18 to 1000) -Monosaccharide -Disaccharide -Oligosaccharide - Amino acids -Lipids -Nucleotides -Polysaccharide -Proteins - Nucleic acids (DNA , RNA )

4. Monomer : simple molecule which is used as a basic building block for the synthesis of a polymer; many monomers are joined together to make the polymer, usually by condensation reactions e.g. monosaccharides, amino acids, nucleic acids. Polymer : is a giant molecule made from monomers e.g. polysaccharides, proteins, nucleic acids. Types Natural polymers : Cellulose , Rubber. Synthetic / Artificial polymer: Polyester, Polythene, PVC (Polyvinyl chloride and Nylon)

5. Macromolecule : These are large and complex molecules that are formed due to polymerisation of smaller monomers e.g. polysaccharides, nucleic acids.

6. 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

7. 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.

8. PROPERTIES OF DISACCHARIDES There are various characteristics of these sugars. They are explained below. They are crystalline in nature. They are water-soluble. They are composed of hydrogen, carbon, and oxygen( hydrates of carbon). The chemical formula of these is C 12 H 22 O 11 . The covalent bond is present as in other organic compounds.

9. 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 ii. TREHALOSE Example : i. LACTOSE ii. MALTOSE iii. CELLOBIOSE CLASSIFICATION

10. DISACCHARIDES =C n (H2O) n-1 α GLUCOSE + α GLUCOSE = MALTOSE α GLUCOSE + β FRUCTOSE = SUCROSE β GLUCOSE + β GALACTOSE = LACTOSE

11. 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 .

12. 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. Sweeteners in pastries Maltose, sometimes called malt sugar, comes from the hydrolysis of starch. It is about one third as sweet as cane sugar (sucrose), is easily digested by humans, and is fermented by yeast.

13. α D GLUCOSYL (1  4) α D GLUCOSE

14. 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. Lactose, also known as milk sugar, is a galactose-glucose compound joined as a beta-glycoside. It is a reducing sugar because of the hemiacetal function remaining in the glucose moiety. Many adults, particularly those from regions where milk is not a dietary staple, have a metabolic intolerance for lactose.

15. 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. Digested by lactase Lactose can be converted to lactic acid FUNCTIONS Widely used in food industry. Also used as filler in tablets.

16. β - D galactosyl (1 4) β - D glucose

17. sucrose STRUCTURE The glucose part had the aldehyde at carbon 1 , and the fructose part had the ketone group at carbon 2 . Since the linkage is 1,2, neither group is free. Therefore, sucrose is not a reducing sugar . Sucrose, or cane sugar, is our most commonly used sweetening agent. It is a non-reducing disaccharide composed of glucose and fructose joined at the anomeric carbon of each by glycoside bonds (one alpha and one beta). In the formula shown here the fructose ring has been rotated 180º from its conventional perspective.

18. 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).

19. α D glucosyl (1 2 ) β D fructose

20. Trehalose serves as an energy storage chemical in the circulating fluid (hemolymph) of insects, where it is a notable component. The same can be said for yeasts and other parasites. In this instance, the two -D-glucose moieties’ two anomeric carbon molecules come into contact with one another. As a result, it resembles sucrose in that it is a nonreducing sugar because it does not accumulate free aldehydes. An osazone is not surrounded by trehalose. When hydrolyzed, it produces glucose. Trehalose Finally, it may be noted that trehalose has a distinctly sweet taste, but gentiobiose is bitter.

21. CELLOBIOSE Obtained by partial hydrolysis of cellulose, cellobiose consists of two β-D-glucopyranose units joined by a 1→4-β-glycoside bond 1. Unlike maltose, cellobiose can’t be digested by humans or fermented by yeast. Cellobiose is obtained by the hydrolysis of cellulose. It has virtually no taste, is indigestible by humans, and is not fermented by yeast. Some bacteria have beta-glucosidase enzymes that hydrolyze the glycosidic bonds in cellobiose and cellulose. The presence of such bacteria in the digestive tracts of cows and termites permits these animals to use cellulose as a food.

22. C6H12O6 +C6H12O6 ---- >C12H22O11 +H20

23. MALTOSE LACTOSE SUCROSE GLUCOSE (1)+GLUCOSE 4 GALACTOSE 1+ GLUCOSE 4 GLUCOSE 1 + FRUCTOSE 2 PANCREATIC AMYLASE INTESTINAL LACTASE SUCRASE GLYCOSIDIC BOND GLUCOSE α (1--->4) β GAL(1---4) β GLUCOSE α GLUCOSE (1-  2) β FRUCTOSE REDUCING SUGAR REDUCING SUGAR NON REDUCING SUGAR SUNFLOWER SHAPED OSAZONES LADY POWDER PUFF OSAZONES NO OSAZONES SOURCE –DIGESTION OF STARCH MILK SUGAR CANE SUGAR,BEET SUGAR DISACCHARIDES ---CRYSTALLINE, WATER SOLUBLE ,SWEET TASTE ,FORM OSAZONES (EXCEPT SUCROSE )

24. They are a good source of energy. The human body uses disaccharides as an energy source, and plants also utilize them for a number of purposes (including transporting nutrients around the plant). Since a disaccharide is made up of two monosaccharides, generally known as single sugars, it can also be categorized as a double sugar. Chest milk contains lactose, which provides newborns with nutrition. Maltose is a sugar that is frequently included in chocolate and other sweets. Sucrose is a carbohydrate that gives the body the energy it needs to carry out both physical and mental tasks. During digestion, the body converts nutrients like sucrose and starch into fructose and glucose. The body breaks down fructose and glucose to give the cell energy. significance

25. Emil Fischer invented osazone formation and used the technique to identify monosaccharides. Both oxidation and condensation reactions are necessary for the synthesis of a pair of hydrazone functionalities. Only “reducing sugars” can function in the reaction since a free carbonyl group is necessary. The nonreducing sugar sucrose does not produce an osazone . The time for the formation of osazone identifies the types of carbohydrates present in the samples. Every carbohydrate has its different and unique structure of osazone and its time of formation. Maltosazone , which derives from maltose, crystallizes into petals. Lactosazone crystals have the shape of powder puffs when made from lactose. From galactose, galactosazone crystallizes into rhombic-plate-shaped structures. Broomstick- or needle-shaped crystals of glucosesazone (made from glucose, fructose, or mannose) are produced. Cotton-ball-shaped osazone was produced by lactose.

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