Which one of the following carbohydrates will show mutarotation?
Answer & explanation
Correct answer: option 1
The answer is (1) maltose.
Mutarotation is the change in optical rotation of a cyclic sugar due to the interconversion of the alpha and beta anomers. Maltose is a disaccharide composed of two glucose units linked together by an \(\alpha\)-1,4-glycosidic bond. This bond allows the anomeric carbon of the glucose units to be free, which is necessary for mutarotation to occur.
Sucrose, starch, and cellulose are all non-reducing sugars. This means that they do not have a free aldehyde or ketone group, which is necessary for mutarotation to occur. Therefore, only maltose will show mutarotation.
Here is a table of the four carbohydrates and their ability to show mutarotation:
|
Carbohydrate |
Ability to Show Mutarotation |
|
Maltose |
Yes |
|
Sucrose |
No |
|
Starch |
No |
|
Cellulose |
No |