AP BIOLOGY

Detailed explanation-1: -We can use a special reagent called Benedict’s solution to test for simple carbohydrates like glucose. Benedict’s solution is blue but, if simple carbohydrates are present, it will change colour – green/yellow if the amount is low and red if it is high.

Detailed explanation-2: -When glucose is mixed with Benedict’s reagent and heated, a reduction reaction causes the Benedict’s reagent to change color. The color varies from green to dark red (brick) or rusty-brown, depending on the amount of and type of sugar. Glucose never gives violet colour precipitate with Benedict’s solution.

Detailed explanation-3: -Benedict’s solution is used to detect reducing sugars, typically monosaccharides or disacharides. It will show a positive result for reducing sugars such as glucose, fructose, lactose, maltose, galactose. It will show a negative result for non-reducing sugars such as sucrose, starch.

Detailed explanation-4: -The Benedict’s Solution provides a test for the presence of simple sugars. If sugar is present, the Benedict’s Solution will turn color (shades of yellow, orange, brown).

Detailed explanation-5: -Sucrose contains two sugars (fructose and glucose) joined by their glycosidic bond in such a way as to prevent the glucose isomerizing to aldehyde, or the fructose to -hydroxy-ketone form. Sucrose is thus a non-reducing sugar, which does not react with Benedict’s reagent.