Where is glycogen predominantly stored in the body?

Glycogen is a crucial storage form of glucose in the body, primarily serving as an energy reserve. It is predominantly stored in the muscles and liver.

In the muscles, glycogen functions as a readily available source of energy during physical activity, particularly high-intensity exercise. Muscles utilize this stored glycogen to rapidly generate ATP, facilitating muscular contractions.

In the liver, glycogen plays a vital role in regulating blood glucose levels. When blood sugar levels drop, the liver can convert glycogen back into glucose and release it into the bloodstream to maintain energy homeostasis.

The other locations mentioned, such as the gastrointestinal tract and fat cells, do not serve as significant stores of glycogen. While fat cells store energy, they do so in the form of triglycerides rather than glycogen. Hence, the correct answer accurately reflects the primary storage sites of glycogen within the body.