Answer to Question #253153 in Biochemistry for Morgana

Question

Why glucose, maltose, and starch negative for Seliwanoff's test while sucrose and fructose is positive. Can you give me a detailed answer aside from it's change of color. Thank you.

Answer 1

As starch is a polysaccharide, it is unsurprising that the starch solution tested negative for simple sugars. This is because HCl breaks starch back down into its component monosaccharides (glucose, in this case). Amylase is an enzyme that removes glucose molecules from starch.