Chapter 26, Problem 26.23YT

Interpretation Introduction

Interpretation:

There is one glycosidic linkage not highlighted in Figure 26-52 and another in Figure 26-53. Each one is to be identified, and the kind of glycosidic linkage is to be classified.

Concept introduction:

Polysaccharides are long chains of carbohydrate molecules. The monosaccharide units are combined together by glycosidic bond to form polysaccharides. Figure 26-52 is that of amylopectin, and Figure 26-53 is that of cellulose.

Amylopectin, a branched storage polysaccharide, consists of a main chain that consists of glucose units joined by ${\text{α-1-4}}^{\text{'}}$-glycosidic linkages. Branching takes place via ${\text{α-1-6}}^{\text{'}}$-glycosidic linkages (Fig. 26-52), which occur roughly every $\text{25–30}$ glucose units.

Cellulose, a structural polysaccharide, is the main component of plants’ cell walls, making up about one-third of all plant matter. Cellulose consists of long, unbranched chains of d-glucose. In cellulose the glucose units are linked by ${\text{β-1-4}}^{\text{'}}$-glycosidic linkages.