What is the primary feature of glycogen in animals?

The primary feature of glycogen in animals is its highly branched structure, with branches occurring approximately every 8 to 12 glucose residues. This branching is crucial because it allows for rapid release of glucose when energy is needed by the body. Glycogen serves as a key energy storage molecule, and the branching structure increases the number of terminal ends from which glucose can be mobilized quickly, making it highly efficient for quick energy release during periods of fasting or intense exercise.

In contrast, a linear structure with few branches would not facilitate rapid glucose release, making it less effective for energy storage. The option relating to structural purposes misidentifies the primary function of glycogen, which is primarily energy storage rather than providing structural support. Furthermore, glycogen is predominantly found in animal cells, not plant cells; plants primarily store energy in the form of starch, which has a different structure and branching pattern compared to glycogen. This understanding helps highlight the unique role of glycogen in animal metabolism.