Carbohydrate Test

University:
Augusta University
Course:
CHEM 1441 | General Chemistry
Academic year:

2023
Views:

233

Pages:

1
Author:

gmandels

Carbohydrate Test108 Molisch test Molisch reagent consisting of ÿ-naphthol in alcohol will react with furfural to form a purple complex compound which is caused by the dehydrating power of concentrated sulfuric acid towards carbohydrates. A negative reaction result indicates that the solution being examined does not contain carbohydrates. Meanwhile, the formation of a purple ring indicates a positive reaction. Benedict's Test Alkaline copper solutions will be reduced by sugars that have free aldehyde or ketone groups to form colored cuprooxide. Reducing sugars react with reagents to produce a brick red precipitate (Cu2O). In reducing sugars there are aldehyde groups and OH lactol. The OH of lactol is the OH attached to the first C atom which determines whether the carbohydrate is a reducing sugar or not. Barfoed Test This test is to differentiate monosaccharides and disaccharides. In this experiment, carbohydrates were reduced in an acidic environment. Disaccharides will also give positive results if boiled long enough for hydrolysis to occur. Seliwanoff test This reaction is specific for ketose. The basis is the change in fructose by hot acid into levulinate and hydroxymethylfurfural which then condense with resorcinol to form a red compound. Tollens test This test is positive for pentose carbohydrates which differentiates them from hexoses. Sucrose Hydrolysis Sucrose is a disaccharide carbohydrate. Sucrose hydrolysis is to prove whether the hydrolysis results of sucrose are glucose and fructose, that is, after the sucrose is hydrolyzed, the hydrolyzed solution is tested using the Benedict test to prove glucose and the Seliwanoff test to prove there is fructose. Glycolysis experiments in yeast In humans and animals, the final product of anaerobic glycolysis is lactic acid, while in yeast anaerobic glycolysis (sugar fermentation) produces ethanol. In this experiment we will see the results of anaerobic glycolysis in yeast in the form of CO2 and ethanol. Apart from that, we will also look at the effect of inhibitors on anaerobic glycolysis.