Glycogen

Glycogen is a highly branched polymer made up of glucose molecules. It serves as the main storage form of glucose in animals, including humans.

Structure

Glycogen consists of a core protein called glycogenin, around which glucose molecules are attached in a highly branched fashion. The branching allows for quick access to stored glucose when energy is needed.

Function

Glycogen serves as a readily available source of glucose for cells when blood glucose levels drop. It acts as a short-term energy reserve, particularly in liver and muscle cells, and plays a crucial role in maintaining normal blood sugar levels.

Storage

Glycogen is primarily stored in the liver and muscles. In the liver, it acts as a buffer to prevent glucose levels from dropping too low between meals. In muscles, glycogen provides energy during physical activity.

Regulation

The synthesis and breakdown of glycogen are tightly regulated by various enzymes and hormones. Insulin promotes glycogen synthesis, while glucagon and epinephrine stimulate glycogen breakdown, ensuring a balance of energy utilization.

Importance

Glycogen plays a vital role in maintaining energy homeostasis in animals. It allows for the efficient storage and release of glucose, ensuring a steady supply of fuel for various cellular processes.