And
Enzymatic Activity
Blood Glucose Regulation and Enzymatic Activity
Blood glucose levels in the human blood need to be balanced; as otherwise, it would lead to several fatal consequences and ill physical health. Uncontrolled blood glucose levels may damage blood vessels which supply blood to important organs such as the heart, kidneys, lungs, brain etc. Homeostasis in blood glucose levels is maintained by the coordinated efforts of two vital hormones – insulin and glucagon, along with action by certain enzymes. All these work together, to maintain homeostasis in the body according to body needs. Insulin is secreted by the β-cells of the pancreas. Its vital function is to lower blood glucose levels. When there is a rise in the blood glucose levels, levels of insulin secretion are high in order to maintain homeostasis.
Glucagon is a counteracting hormone to insulin. It is secreted by the α-cells of the pancreas and its vital function is to release glucose stored in the liver, into the blood, as and when needed by the body. Glucagon also converts amino acids to glucose and breaks down stored fat into fatty acids to be used up by the cells. Both insulin and glucagon work in conjunction with each other to achieve balanced blood glucose levels. After a meal, blood glucose levels rise due to which there are higher levels of insulin secretion, which take away glucose from the blood. During such a condition, no glucagon is secreted. In-between meals and during exercise, blood glucose levels fall. This initiates release of glucagon to elevate the levels and no insulin is released then.
The normal blood glucose level is between 70mg/dl and 110mg/dl. Hypoglycemia occurs when the blood glucose level is below 70mg/dl and hyperglycemia occurs when the levels are greater than 110mg/dl. In addition to insulin and glucagon, enzymatic action also plays an important role in the functioning of these hormones to maintain blood glucose levels. Enzyme glucose-6-phosphatase catalyzes the terminal step in both gluconeogenic and glycogenolytic pathways (Nordlie et al, 1999, p. 379). At the terminal step, it is opposed by the enzyme glucokinase. These enzymes are secreted by the exocrine glands of the pancreas to aid in breakdown of carbohydrates which thus increase the blood glucose level.
References
Brown University. (2016). Insulin/Glucagon. Retrieved from Brown University.Edu
http://www.biomed.brown.edu/Courses/Bl108/Bl108_2002_Groups/pancstems/stemcell/insulin_glucagon.htm
Nordlie, R.C., Foster, J.D., & Lange, A.J. (1999). Regulation of glucose production by the liver. Pub Med,
19: 379-406.
