What tissue in the human body stores glucose for later use as glycogen? heart and bone kidneys and liver muscle and bone muscle and liver
The correct answer and explanation is:
Correct Answer: Muscle and liver
Explanation (300 words):
The human body stores glucose for later use in the form of glycogen, a complex carbohydrate made of glucose molecules. The two main tissues responsible for glycogen storage are the liver and skeletal muscles, making “muscle and liver” the correct answer.
Liver Glycogen:
The liver plays a key role in maintaining blood glucose levels. It stores glycogen and releases glucose into the bloodstream when blood sugar levels drop, such as between meals or during fasting. This process is called glycogenolysis. Liver glycogen can be broken down into free glucose that is transported throughout the body to supply energy to cells, especially the brain and red blood cells.
Muscle Glycogen:
Skeletal muscles also store a large amount of glycogen, but this glycogen is used locally by the muscles for energy, especially during physical activity. Unlike the liver, muscle cells do not have the enzyme glucose-6-phosphatase, which is necessary to release glucose back into the bloodstream. Therefore, muscle glycogen is used only within the muscle cells that store it.
Why Not Other Options?
- Heart and bone: The heart uses glucose and fatty acids for energy but doesn’t store significant amounts of glycogen. Bone stores minerals like calcium and phosphorus, not glycogen.
- Kidneys and liver: Kidneys can perform gluconeogenesis (make new glucose), but they do not store much glycogen.
- Muscle and bone: Muscles store glycogen, but bone does not.
Summary:
Glycogen is stored mainly in the liver (for blood glucose regulation) and skeletal muscles (for muscle energy use). This storage system allows the body to maintain energy availability and blood sugar balance, especially during fasting or intense physical activity.