Question

Storage carbohydrates and fiber in both plants and animals are made from glucose but vary by where bonds form, as shown in this diagram. 3 molecules are shown. Starch has a long single chain in a flat line with 3 short side chains. Fiber is one long, flat chain. Glycogen has a long chain that bends at different angles and 5 side chains of varying lengths. Which of the following statements best describes the advantage of the branching of a storage carbohydrate, whether in plants or animals?

A) The branches enable a carbohydrate to accumulate in all areas in plants and animals.
B) A branched structure enables hydrolysis by water molecules to break down and release the energy.
C) A branched structure takes up less space and reduces the energy a plant or animal requires.
D) Branched molecules take up less space and therefore a plant or animal can store more energy.

Answer 1

B) A branched structure enables hydrolysis by water molecules to break down and release the energy.

Step-by-step explanation:

Storage polysaccharides like glycogen and starch are branched molecules composed of glucose units with glycogen even more highly branched than starch molecules. Starch is the storage polysaccharide in plants while glycogen is the storage polysaccharide in animals.

The role of branching is to provide a larger surface area for hydrolytic enzymes to act in order to release the glucose stores more readily when the energy requirements of the cells increases. This can be seen in the degree of branching in both starch and glycogen. Since animals have a greater metabolic rate than animals, glycogen is much ore branched than starch molecules in order to provide a greater surface area for hydrolytic enzymes to release more glucose molecules faster.