Blood sugar level In humans, glucose is the primary source of energy, and is critical for normal function, in a number of tissues, particularly the human brain which consumes approximately 60% of blood glucose in fasted, sedentary individuals. Glucose can be transported from the intestines or liver to other tissues in the body via the bloodstream. Cellular glucose uptake is primarily regulated by insulin, a hormone produced in the pancreas. Glucose levels are usually lowest in the morning, before the first meal of the day, and rise after meals for an hour or two by a few millimoles. Blood sugar levels outside the
Christian de Duve to maintain normal blood sugar level. His idea was ridiculed at the time. But his rediscovery of glucagon confirmed his ideas. In 1953 he experimentally demonstrated that glucagon did influence the production and thus uptake of glucose. Christian de Duve continued his research on insulin mechanism of action in liver cells. He and his team focused on the enzyme glucose 6-phosphatase, which is the key enzyme in sugar metabolism (glycolysis) and the target of insulin. They found out that it was the principal enzyme in regulating blood sugar levels. However, they could not purify and isolate the enzyme from the