4 carbohydrate.pptx.....................

0000000000000

1. Practical Biochemistry Reactions of Carbohydrates Presented By Dr Mai Abdelaziz Gouda

2. 1- Molisch’s Test General test for All Carbohydrates. Reagents: - Alcoholic α - naphthol - Concentrated sulfuric acid .(H2SO4)

3. 3 ml of carbohydrate solution 3 drops of Alcoholic α - naphthol Carefully pour 3 ml of conc. sulfuric acid on inner side of tube Procedure: A VIOLET RING The solution is carbohydrate

4. 2- Iodine Test General test for Polysaccharides . Reagents: - Iodine solution.

5. Procedure: 10 ml of Carbohydrate solution Few drops of Iodine BLUE COLOR “Starch” VIOLET COLOR “Dextrin” The sugar may be Dextrin or Starch

6. 3- Fehling’s Test Test for reducing sugars only ( Glucose & Fructose) Reagents: Fehling A solution: Copper sulfate solution. Fehling B solution : NaOH and Rochelle salt.

7. 1 ml Fehling A Procedure: 1 ml Fehling B 2 ml of sugar solution Boil for 2-3 minutes Red precipitate The sugar may be Glucose or Fructose.

8. 4- Seliwanoff’s Test Test for to differentiate ketoses (fructose) from aldoses (glucose). Reagents: - Resorcinol dissolved in HCL

9. 5 ml Seliwanoff’s reagents Procedure: 0.5 ml of Sugar solution Boil for 1 minutes Red Color The sugar is Ketoses “Fructose”.

10. Summary Test Reagent Observation Result Molisch - Alcoholic α- naphthol - Conc H2SO4 Violet ring Carbohydrate Iodine Iodine solution - Blue color (Starch) - Violet Color (Dextrin) Polysaccharide Fehling - Fehling A - Fehling B Red precipitate Reducing sugar Seliwanoff’s Resorcinol dissolved in HCL Red color Ketose (Fructose)

11. 1- Molisch’s 2- Iodine 3- Fehling’s 4- Seliwanoff’s