[Campbell Biology P.120] Glycogen is characterized as an 'extensively branched' polysacchari... | Practice Question

Glycogen is characterized as an 'extensively branched' polysaccharide. Based on the text, why is this extensive branching a crucial structural feature for glycogen's function as an energy storage molecule in animals?

  • A: It makes glycogen completely insoluble, preventing it from interfering with other cellular components.
  • B: The numerous branch points provide many free ends, which allows for rapid hydrolysis and release of glucose molecules when energy is demanded.
  • C: It enables glycogen to form rigid, cable-like structures for robust structural support within animal cells.
  • D: Extensive branching increases the density of the molecule, allowing more glucose to be packed into a smaller volume.

Explanation

The text explicitly states: 'The extensively branched structure of glycogen fits its function: More free ends are available for breakdown.' This means that the numerous branches provide a high surface area with many points from which glucose units can be quickly cleaved off by enzymes, allowing for rapid mobilization of energy when needed.