Question

Amylopectin is the ___ fraction of starch, having a structure chemically described as ____ as glucose molecules are attached with the following linkage. Typically, the above polymer is ___ abundant than the other fraction of starch.

A) Branched, alpha 1-4 and alpha 1-6, more
B) Linear, beta 1-4, less
C) Linear, alpha 1-4, more
D) Branched, beta 1-4 and beta 1-6, less

Answer 1

Amylopectin is the branched fraction of starch, primarily linked by alpha 1-4 and branching alpha 1-6 glycosidic bonds, and is more abundant than amylose in starch.

Step-by-step explanation:

Amylopectin is the branched fraction of starch, having a structure chemically described as alpha 1-4 and alpha 1-6 as glucose molecules are attached with these linkages. Typically, the above polymer is more abundant than the other fraction of starch, which is amylose. Amylopectin is a high-molecular-weight, branched polysaccharide composed of glucose units. The majority of the glycosidic bonds are alpha-1,4 linking linear chains of glucose, and the alpha-1,6 bonds occur at the branching points, which take place roughly every 25-30 glucose units. This structural arrangement disrupts the helical structure of the polymer, leading to its distinctive reddish-brown color when iodine is added, in contrast to the deep blue-violet color produced by amylose.