What is glycogen?

What is glycogen?

• A. Storage form of glucose
• B. Blood sugar
• C. Hormone
• D. Enzyme

Answer: (A)

Glycogen is the storage form of glucose, a large, highly branched polymer of glucose units that can be quickly mobilized to provide energy. Most glycogen sits in the liver and skeletal muscles. In the liver, it helps keep blood glucose levels stable between meals, supporting tissues that rely on glucose, like the brain. In muscle, glycogen serves as an immediate fuel source for contraction during activity, but it isn’t released into the bloodstream. The structure—with many branches—allows rapid synthesis and rapid breakdown when energy is needed. This storage form is built up by glycogen synthesis and broken down by glycogenolysis, regulated by hormones such as insulin (which promotes storage) and glucagon/epinephrine (which promote release). It’s not blood sugar itself, nor a hormone, nor an enzyme.

Glycogen is the storage form of glucose, a large, highly branched polymer of glucose units that can be quickly mobilized to provide energy. Most glycogen sits in the liver and skeletal muscles. In the liver, it helps keep blood glucose levels stable between meals, supporting tissues that rely on glucose, like the brain. In muscle, glycogen serves as an immediate fuel source for contraction during activity, but it isn’t released into the bloodstream. The structure—with many branches—allows rapid synthesis and rapid breakdown when energy is needed. This storage form is built up by glycogen synthesis and broken down by glycogenolysis, regulated by hormones such as insulin (which promotes storage) and glucagon/epinephrine (which promote release). It’s not blood sugar itself, nor a hormone, nor an enzyme.