How Does Insulin Metabolize Glucose?

Insulin is a hormone secreted in the pancreas by specialized cells called islet cells. Once released in the circulatory system, it allows cells throughout the body to metabolize glucose and use it as an energy source.

Basics

According to the peer-reviewed EndocrineWeb, carbohydrates and sugars eaten during meals enter the bloodstream after being absorbed in the large intestine. On their own, the body's cells cannot use the blood glucose that results from this process.

Insulin Release

In response to the increase in blood glucose, the pancreas releases insulin. Special receptors on the surfaces of most cells latch onto insulin molecules and bind them to the cells.

Glucose Metabolism

The presence of insulin molecules on their surfaces makes cells activate additional receptors that metabolize glucose (give it access to the cells' interiors).

Glucose Levels

When insulin levels rise inside the body, any glucose not currently needed gets stored inside the liver as a substance called glycogen, according to the Mayo Clinic. When insulin levels fall between meals, the liver releases glycogen as a type of sugar that keeps blood glucose from dropping too low.

Insulin and Diabetes

Diabetics require external sources of insulin when the pancreas produces little or no native insulin, or when the body cannot use existing insulin properly.

References

• EndocrineWeb: Diabetes - What is Insulin?
• The Mayo Clinic: Diabetes Treatment - Using Insulin to Manage Your Blood Sugar

Resources

• American Diabetes Association: Insulin Basics