Question

Which one is not disaccharide?

• A. Lactose
• B. Sucrose
• C. Maltose
• D. Starch

Answer 1

Answer: (D)

Starch

Starch is a polymer of glucose. It is formed by the attachment of several glucose unit by glycosidic bonds. The basic formula of starch is (C${}_6$H${}_{10}$O${}_5$)n. It is made of two types of molecules the amylose which is the soluble fraction of starch and amylopectin the insoluble fraction. Amylose is formed by alpha 1,4 linkage of glucose units. It is a linear polymer. Amylopectin, on the other hand is a branched polymer of glucose which in addition to the alpha 1,4 chain has an alpha 1,6 branching point.

So, the correct answer is option D.