What is the primary function of glycogen in the body?

Glycogen serves as the primary storage form of glucose in the body. It is a polysaccharide composed of numerous glucose units that are branched together, allowing for a rapid release of glucose when energy is needed. The liver and muscle tissues are the main sites for glycogen storage. When blood glucose levels drop, glycogen can be broken down (a process known as glycogenolysis) to release glucose into the bloodstream, providing energy for various bodily functions.

The significance of glycogen storage is particularly evident during periods of fasting or intense physical activity, when the body requires a quick source of glucose to maintain energy levels. This function is crucial as glucose is the primary fuel for many cells, especially in the brain and muscles.

The other options are not related to the primary function of glycogen. Fats are stored as triglycerides in adipose tissue, and insulin is a hormone produced by the pancreas that regulates glucose levels, while proteins are broken down through different pathways that do not involve glycogen. Understanding glycogen's role highlights its importance in metabolic processes and energy homeostasis in the body.