Final answer:
Structural carbohydrates like cellulose and chitin possess long chains of monosaccharides interconnected by strong bonds such as hydrogen and peptide bonds, forming rigid and fibrous sheets capable of withstanding mechanical forces.
Step-by-step explanation:
Carbohydrates that function as structural molecules are able to withstand pulling and pushing forces well due to their long chains of monosaccharides that are cross-linked into fibrous sheets. The rigidity and strength are imparted by hydrogen bonds or peptide bonds that connect these monosaccharide chains. Additionally, cellulose and chitin are examples of such structural carbohydrates, commonly found in the cell walls of plants and the exoskeletons of arthropods, respectively.
Cellulose, for example, is made from a linear chain of glucose molecules, which forms rigid structures due to the orientation of the glycosidic linkages between glucose units. This contrast with energy storage carbohydrates like starch and glycogen, which are branched rather than linear, and have different properties because of the different orientations of their glycosidic linkages.
The structural integrity provided by these complex carbohydrates enables cells and organisms to maintain shape and resist environmental stresses. In essence, the molecular structure of these carbohydrates determines their function as either energy-storing or structural molecules.