Glucose is a simple sugar critical for sustaining life. The sugar is an ingredient in countless foods. Additionally, glucose is the end product resulting from the digestion of more complex carbohydrates. Glucose is the energy source for the human body. Too much or too little glucose in the blood affects the proper functioning of cells. If glucose levels remain elevated for a prolonged period, diabetes can develop.
What is Glucose
Glucose is one of the simplest forms of sugar, explains the website Vitamin Supplement Guide. A monosaccharide, glucose is a type of carbohydrate. Glucose circulates in the bloodstream and is sometimes called blood sugar. The amount of glucose present in the blood is controlled by the hormone insulin, which is produced by the pancreas. Diabetes results when the pancreas fails to produce enough insulin to properly manage blood glucose levels.
Sources
The body breaks down dietary carbohydrates to form glucose, according to Vitamin Supplement Guide. Digestion reduces carbohydrates to sugars, including glucose. The intestinal walls absorb glucose and it enters the bloodstream.
Roles
Glucose supplies the energy that cells require to carry out their functions, notes Vitamin Supplement Guide. As glucose circulates throughout the body, insulin released by the pancreas enables glucose to enter cells. Cells cannot absorb glucose without insulin. Once inside the cells, the mitochondria metabolize glucose to release energy. The cytoplasm also metabolizes glucose but not as efficiently as the mitochondria. Glucose is particularly important in powering brain and muscle cells. The body must maintain glucose levels within a specific range or brain cells cannot properly function.
Levels
Insulin maintains the level of glucose circulating in the blood. After eating, the percentage of glucose in the blood rises, reports the website NetWellness. The rising glucose levels stimulate the pancreas to produce insulin. Insulin enables the glucose in the blood to enter cells where it can be used. As glucose blood levels drop, the pancreas produces less insulin. Blood glucose levels must remain within a narrow range, between 65 and100 mg/mL of blood. If glucose levels drop too low, for example, if you are hungry or have been exercising vigorously, you experience hypoglycemia, warns the New York State Department of Health. Symptoms include shaking, hunger, sweating, rapid heartbeat, nervousness or irritability and fatigue. Glucose levels that are too high cause hyperglycemia. Hyperglycemia can result from overeating, inactivity or incorrectly taking diabetes medications. Symptoms of hyperglycemia include blurred vision, extreme thirst, frequent urination and drowsiness.
Storage
Glucose not immediately needed circulates to the liver, where it is converted to glycogen and stored, notes Vitamin Supplement Guide. Excess glucose is also stored as fat in fat cells. When glucose levels drop, the body can convert glycogen back into glucose. Fat is a less efficient backup energy source because the body must convert fat into an intermediate compound before processing it into usable glucose.
Commercial Uses
Glucose derived from plant sap has important commercial uses, according to Vitamin Supplement Guide. Glucose is a general sweetener and is used in many food products, including candies, pastries, jellies and syrups. Liquid glucose is sold as corn syrup.
