carb Laboratory report - Nurul Nadzirah Roslan 007544407...

carb Laboratory report
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Nurul Nadzirah Roslan 007544407 Carbohydrate Chemistry Laboratory Report Part I: Galactaric Acid Test Purpose: Galactaric acid test differentiates galactose containing sugars from other sugars, can differentiate lactose and galactose by time and amount of precipitate formation. Reaction: Procedure: Five test tubes are labeled with the four known carbohydrate names or the unknown number. 0.5 g carbohydrate is weighed into a heat resistant labeled test tube. 1 mL DI H 2 O and followed by 1 mL concentrated nitric acid is added into the carbohydrate. The test tubes is mixed and placed into a beaker with water, boiling water bath in the hood. Tubes are leaved in water bath for 1.0 to 1.5 hours. The beaker is then carefully removed off from the plate. Allowed to cool. Parafilm tubes and the tubes are kept in the beaker. The beaker is kept in the hood until next week. Next week: observation of presence (or absence) of white crystal as + or – result is recorded. Carbohydrates : Tested glucose, galactose, lactose, sucrose and unknown Y-319C Results: A positive result was the formation of white crystal, which was the result for galactose, lactose and unknown Y-319C. A negative result is solution with no precipitate formed which was the result for glucose and sucrose. Benedict’s Acid Test Purpose: Benedict’s test differentiates between reducing and non-reducing sugars. Reaction: Procedure: 11 heat resistant test tubes is used and labeled with the appropriate carbohydrate tested. 2 mL Benedict’s reagent is added into each test tube. 0.2 mL of the 10% carbohydrate solution to the appropriate tube. Mixed well. Test
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