glikogénje

Glycogen, also known as animal starch, is a complex carbohydrate that serves as a major energy reserve in the body. It is primarily stored in the liver and muscles, where it can be rapidly broken down to glucose when energy is needed. Glycogen is composed of glucose units linked together in a highly branched structure, which allows for efficient storage and release.

The synthesis of glycogen, known as glycogenesis, occurs primarily in the liver and muscle cells. During glycogenesis, glucose molecules are added to a glycogen molecule, forming a glucose-1-phosphate linkage. This process is facilitated by enzymes such as glycogen synthase and glycogenin. Glycogen synthesis is regulated by hormones such as insulin, which promotes the storage of glucose as glycogen.

The breakdown of glycogen, known as glycogenolysis, occurs when the body needs glucose for energy. This process is initiated by the hormone glucagon, which activates enzymes such as phosphorylase. Glycogenolysis results in the release of glucose-1-phosphate, which can be converted to glucose-6-phosphate and then to glucose. Glucose can then be used by the body for energy or converted to other molecules as needed.

Glycogen plays a crucial role in maintaining blood glucose levels and providing energy during periods of fasting or exercise. It is also involved in various physiological processes, such as the regulation of insulin sensitivity and the storage of glycogen in the brain. However, excessive glycogen storage can lead to conditions such as glycogen storage diseases, which are characterized by the accumulation of glycogen in various tissues.