Carbohydrates are a large group of organic compounds occurring in and including,, and. They contain hydrogen and oxygen in the same ratio as (2:1).

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2 Carbohydrates are a large group of organic compounds occurring in and and including,, and. They contain hydrogen and oxygen in the same ratio as (2:1).

3 Why we study carbohydrates 1) carbohydrates are the first products formed in photosynthesis

4 2) Although animals can synthesize some carbohydrate form fat & protein but the bulk of animal carbohydrate is derived ultimately from plants. 3) Glucose in plants synthesized from CO 2 & H 2 O by photosynthesis & stored as starch or converted to cellulose.

5 4) Glucose is the fuel of the tissues of the body & it can be converted to other carbohydrate having special as: Ribose Galactose Nucleic acid Lactose (in milk)

6 Sources Fats, oils & sweet Meat, egg, fish, poultry, milk, yogurt & cheese Fruit and vegetables Bread,pasta, cereal and rice

7 We have 2 broad groups: 1) SUGARS 2) POLYSACCHARIDES

8 SUGARS Are crystalline, soluble in water with sweet taste, they are classified to: : compounds that cannot be hydrolyzed to simpler sugars.

9 2 3 4 compounds that yield monosacch aride molecules on hydrolysis All these types represent

10 Monosaccharides Monosaccharides are classified by the number of carbon atoms in the molecules. 3 carbon atoms called " " 4 carbon atoms called " " 5 carbon atoms called " " 6 carbon atoms called " " & so on

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13 Is a common way of writing a structural formula to represent the cyclic structure of monosaccharides with a simple three-dimensional perspective. the sugars appear in open chain form and the carbon atoms of a sugar molecule are connected vertically by solid lines, while carbon-oxygen and carbonhydrogen bonds are shown horizontally.

14 Its a ring stricter between C1 & C5 to produce the pyran (pyranose) ring or between C1 & C4 to produce the furan (furanose) ring. Each OH and H written above and below instead of right and left so what is on: Right below left above

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18 Hexoses Hexoses are the most important monosaccharide found in the plants, they are first detectable sugars synthesized by plants & form the units from which most of the are constructed.

19 There are 16 possible aldohexoses & 8 ketohexoses & if we consider both α & β form we will get 48 isomers. Of these isomers only 2 occur in the, they are: ( ) & ( ), both are found in sweet fruits, honey & invert sugar. When is hydrolyzed it yields whereas yields. Inuline is polysaccharides produced by many types of plants, industrially most often extracted from

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21 Disaccharides Sucrose (α-d-glucopyranosyl-β-d -fructofuranoside) is the only disaccharide that occur abundantly in the free state in plants, although maltose has occasionally been reported in the cell sap. But it different from ribose

22 The presence of these groups (C=O of aldehyde & ketone) explains the reducing properties of monosaccharides & accounts for the commonly applied term " reducing sugars"

23 Reducing and Non Reducing Sugars Reducing sugars are sugars that can act chemically as a reducing agent, which means that they are easily oxidized. sugars, like,,, and a sugars are, such as. The common table sugar, disaccharide. Reducing sugars are chemically different from by the presence of either a. The presence of reducing sugars is determined chemically by several common test methods like using Benedict's reagent or a

24 Upon hydrolysis yields which consists of equimolecular quantities of glucose &. Sucrose is a sugar. Why??????????

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