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How are carbohydrates classified ? |
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Answer» Solution :On the basis of their hydrolysis products , carbohydrates are classified as : (1) Simple carbohydrates and (2) COMPLES carbohydrates. (1) Simple carbohydrates : The simple carbohydrates cannot hydrolsed further to simpler compounds . They are the basic units of all carbohydrates , and are called monosaccharides . They are sugars which are crystalline , water soluble and have sweet taste. Examples : glucose , fructose , ribose. Monosaccharides are further classified as aldoses, containing an aldehyde group and ketoses , containing keto group . DEPENDING upon number of carbon atoms and the functional groups , monosaccharides are further classified as triose , tetrose ,, pentose , hexose etc. (2) Complex carbohydrates : The complex carbohydrates are further classified as (A) Oligosaccharides and (B) Polysaccharides. (a) Oligosaccharides : An oligosaccharide is a carbohydrates (sugar) which on hydrolysis gives two to ten monosaccharide units. Depending on the number of monosaccharides produced on hydrolysis , oligosaccharides are further classified as : (1) Disaccharides `( C_(12)H_(22)O_(11) )` : Sucrose `overset("Hydrolysis")to ` Glucose + Fructose Maltose `overset("Hydrolysis")to ` Glucose +Glucose Lactose `overset("Hydrolysis")to` Glucose + Galactose (2) Trisaccharides `(C_(18)H_(32)O_(16))` : RAFFINOSE `overset("Hydrolysis")to ` Glucose + Fructose + Galactose (3) Tetrasaccharides `(C_(24)H_(42)O_(21))`: Stachyose `overset("Hydrolysis")to` Glucose + Fructose + Galactose + Galactose Oligosaccharide is homogenous . In this , each molecule of oligosaccharide contains the same number of monosaccharide units joines together in the same order as very other molecule of the same oligosaccharide. (b) Polysaccharides : These are carbohydrates which on hydrolysis give a large number of monosaccharides. Polysaccharides are tasteless , amorphous , insoluble in water. They are long chain, naturally occuring polymers of carbohydrates. E.g., cellulose, starch , glycogen. |
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