Difference Between Insulin and Glucagon

Main Difference

The main difference between insulin and glucagon is that insulin is a hormone produced in the pancreas by the islets of Langerhans, which stimulate the amount of glucose in the blood whereas glucagon is a hormone formed in the pancreas which stimulates the breakdown of glycogen to glucose in the liver.

Insulin vs. Glucagon

Insulin and glucagon are hormones secreted within the pancreas by islet cells and therefore refer as pancreatic endocrine hormones. Insulin and glucagon are secreting in response to blood sugar levels but oppositely. Insulin is secreted in the pancreas by the beta cells, but glucagon is secreting by the alpha cells of the pancreatic islets. Insulin effects only some cells, including muscle cells, red blood cells, and fat cells while glucagon affects many cells of the body, but mostly the liver cells. High blood glucose is the stimulus for insulin secretion, but glucagon is secreting in a low blood glucose level. Insulin decreases blood sugar by signaling the cells to take in glucose whereas glucagon cooperates with the liver to increase blood sugar. Insulin consists of 51 amino acids of an A and B chains that are linked together, while glucagon consists of 29 amino acids. Insulin is produced from a proinsulin precursor while glucagon is producing from a proglucagon precursor molecule. Insulin decreasing levels of blood sugar and fatty acids by stimulating the uptake of sugars into the liver and convert glucose into glycogen. In comparison, glucagon increasing levels of blood sugar and fatty acids by the breakdown of glycogen to form glucose.

Insulin vs. Glucagon

Comparison Chart

InsulinGlucagon
A hormone secreted by the beta cell in response to high blood sugar levelA hormone secreted by alpha cells in response to low blood sugar level
Molecular Structure
51 amino acid of A and B chain link together29 amino acid
Trigger for Secretion
High blood sugar level, certain fatty acid, amino acid, and keto acidLow blood sugar level, exercise, epinephrine, acetylcholine
Precursor Molecule
ProinsulinProglucagon
Effects
Decrease the blood level of glucose and fatty acid.Increase the blood level of glucose and fatty acid.
Abnormalities
Diabetes 1 and Diabetes 2.The alpha cell of tumor of pancreas and cirrhosis of the liver

What is Insulin?

Insulin is hormone generating in the pancreas by the beta cells of the Islets of Langerhans in response to a high sugar level in the blood. Insulin is made up of 51 amino acids and consists of two chains of an A and B that are joined together by sulfur bonds. Insulin is producing from proinsulin hormone that contains three chains of amino acid. The secretion of insulin is primarily triggering by blood sugar levels, some types of fatty acids, keto acids, and amino acids in the arterial blood. As blood sugar level decreases, the levels of insulin also decreases — insulin causing the uptake of glucose into fatty tissue (adipose) in the liver and muscle. Insulin stops the analysis of glycogen in the liver and the formation and release of glucose into the bloodstream. Insulin triggers the uptake of glucose in tissues and results in the lowering of blood sugar levels.

Abnormalities

Diabetes is a disease relating to insulin. In type 1 diabetes insulin is not releasing while in type 2 diabetes the insulin is producing, but no cells respond longer to insulin. Diabetics patient may take insulin injections to compensate for lack of insulin.

What is Glucagon?

Glucagon is a hormone generating in the pancreas by the alpha cells of the Islets of Langerhans in response to low levels of sugar in the blood. Glucagon is a protein consist of a series of 29 amino acids that are linked together. Glucagon is producing from proglucagon hormone. A prohormone convertase enzyme transforms the proglucagon to form glucagon. The secretion of glucagon from alpha cells is causing by low blood sugar levels, by exercise, epinephrine, and acetylcholine. The secretion of glucagon is release ensuring enough blood sugar into the bloodstream during times when a person is not eating, when more sugar is needed, such as during exercise. Glucagon works to increase the levels of glucose and fatty acids in the blood. Glucagon causes the liver to break down and convert glycogen into glucose in a process called glycogenolysis. The results are increasing blood glucose level.

Abnormalities

The tumor present in the alpha cells of the pancreas results in too much glucagon being producing. Cirrhosis of the liver also results in high glucagon levels.

Key Differences

  1. Insulin is a hormone-secreting in response to high blood sugar levels by the beta cells of the Islets of Langerhans in comparison; glucagon is a hormone-secreting in response to low blood sugar levels by the alpha cells of the Islets of Langerhans
  2. Insulin consists of 51 amino acids form an A and B chains that are linked together. Conversely, glucagon consists of 29 amino acids.
  3. Insulin is producing from a proinsulin precursor on the flip side glucagon is formed from a proglucagon precursor molecule.
  4. Insulin is secreting in response to high blood sugar levels, keto acids, fatty acids, and amino acids but glucagon is secreting in response to low blood sugar levels, exercise, epinephrine, and acetylcholine.
  5. Insulin decreases blood sugar level, but glucagon increases blood sugar.
  6. Insulin is secreting when blood sugar is too high whereas glucagon is secreting when blood sugar is very low.
  7. Insulin stimulates glycogenesis which converts glucose into glycogen for storage, while glucagon stimulates glycogenolysis in which glycogen is broken down into glucose.
  8. Diabetes type 1 and Diabetes type 2 can cause minute insulin to produce or a there is a reduced response to insulin, on the contrary, cirrhosis of the liver and an alpha cell pancreatic tumor can cause too much glucagon to produce.

Conclusion

According to the above discussion, it concludes that both inulin and glucagon regulate blood sugar level. Insulin is a hormone produces in the pancreas by the islets of Langerhans, which normalizes the amount of glucose in the blood whereas glucagon is a hormone made in the pancreas which promotes the breakdown of glycogen to glucose in the liver.

Janet White

Janet White is a writer and blogger for Difference Wiki since 2015. She has a master's degree in science and medical journalism from Boston University. Apart from work, she enjoys exercising, reading, and spending time with her friends and family. Connect with her on Twitter @Janet__White

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