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, while glucagon is a hormone formed in the pancreas that stimulates the breakdown of glycogen to glucose in the liver.
Insulin versus glucagon
Insulin and glucagon are hormones secreted within the pancreas by the islet cells and are therefore called pancreatic endocrine hormones. Insulin and glucagon are secreted in response to blood sugar levels, but in the opposite way. Insulin is secreted in the pancreas by beta cells, but the alpha cells of the pancreatic islets secrete glucagon. Insulin affects only a few cells, including muscle cells, red blood cells, and fat cells, while glucagon affects many cells in the body, but primarily liver cells. High blood glucose is the stimulus for insulin secretion, but glucagon is secreted at low blood glucose. Insulin lowers blood sugar by signaling cells to take in glucose, while glucagon cooperates with the liver to increase blood sugar. Insulin consists of 51 amino acids of 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 produced from a proglucagon precursor molecule. Insulin lowers blood sugar and fatty acid levels by stimulating the absorption of sugars in the liver and converting glucose to glycogen. By comparison, glucagon raises blood sugar levels and fatty acids by breaking down glycogen to form glucose. while glucagon consists of 29 amino acids. Insulin is produced from a proinsulin precursor, while glucagon is produced from a proglucagon precursor molecule. Insulin lowers blood sugar and fatty acid levels by stimulating the absorption of sugars in the liver and converting glucose to glycogen. By comparison, glucagon raises blood sugar levels and fatty acids by breaking down glycogen to form glucose. while glucagon consists of 29 amino acids. Insulin is produced from a proinsulin precursor, while glucagon is produced from a proglucagon precursor molecule. Insulin lowers blood sugar and fatty acid levels by stimulating the absorption of sugars in the liver and converting glucose to glycogen. By comparison, glucagon raises blood sugar levels and fatty acids by breaking down glycogen to form glucose.Comparison chart
| Insulin | glucagon |
| A hormone secreted by the beta cell in response to high blood sugar. | A hormone secreted by alpha cells in response to low blood sugar. |
| Molecular structure | |
| 51 amino acids of the A and B chain are joined | 29 amino acids |
| secretion trigger | |
| High blood sugar, certain fatty acids, amino acids, and keto acids | Low blood sugar, exercise, epinephrine, acetylcholine |
| precursor molecule | |
| Proinsulin | Proglucagon |
| effects | |
| It lowers the blood level of glucose and fatty acids. | Increases the level of glucose and fatty acids in the blood. |
| Abnormalities | |
| Diabetes 1 and Diabetes 2. | Alpha cell tumor of the pancreas and cirrhosis of the liver. |
What is insulin?
Insulin is the hormone that the beta cells of the islets of Langerhans make in the pancreas in response to high blood sugar. Insulin is made up of 51 amino acids and consists of two chains of A and B that are linked by sulfur bonds. Insulin is produced from the hormone proinsulin which contains three chains of amino acids. Insulin secretion is primarily triggered by blood sugar levels, some types of fatty acids, keto acids, and amino acids in arterial blood. As blood sugar decreases, insulin levels also decrease, insulin causing glucose uptake into fatty (adipose) tissue in the liver and muscles.
Abnormalities
Diabetes is an insulin-related disease. In type 1 diabetes, insulin is not released, whereas in type 2 diabetes, insulin is produced, but no cells are more responsive to insulin. The diabetic patient may receive insulin injections to compensate for the lack of insulin.
What is glucagon?
Glucagon is a hormone produced in the pancreas by the alpha cells of the islets of Langerhans in response to low blood sugar levels. Glucagon is a protein that consists of a series of 29 amino acids that are linked together. Glucagon is produced from the hormone proglucagon. A prohormone convertase enzyme converts proglucagon to form glucagon. Glucagon secretion from alpha cells is caused by low blood sugar levels, exercise, epinephrine, and acetylcholine. Glucagon secretion is released ensuring enough blood sugar in the bloodstream during times when a person is not eating, when more sugar is needed, such as during exercise. Glucagon works to increase glucose and fatty acid levels in the blood.
Abnormalities
The tumor present in the alpha cells of the pancreas causes excessive production of glucagon. Cirrhosis of the liver also results in high levels of glucagon.
Key differences
- Insulin is a hormone secreted in response to high blood sugar levels by the beta cells of the islets of Langerhans compared; Glucagon is a hormone secreted in response to low blood sugar by the alpha cells of the islets of Langerhans.
- Insulin consists of 51 amino acids that form A and B chains that are linked together. In contrast, glucagon consists of 29 amino acids.
- Insulin is produced from a proinsulin precursor on the other hand, glucagon is formed from a proglucagon precursor molecule.
- Insulin is secreted in response to high blood sugar, keto acids, fatty acids, and amino acids, but glucagon is secreted in response to low blood sugar, exercise, epinephrine, and acetylcholine.
- Insulin lowers blood sugar, but glucagon raises blood sugar.
- Insulin is secreted when blood sugar is too high, while glucagon is secreted when blood sugar is too low.
- Insulin stimulates glycogenesis which converts glucose to glycogen for storage, while glucagon stimulates glycogenolysis in which glycogen is broken down to glucose.
- Type 1 diabetes and type 2 diabetes can cause tiny insulin production or a reduced response to insulin; conversely, cirrhosis of the liver and a pancreatic alpha-cell tumor can cause too much glucagon to be produced.
Final Thought
Based on the discussion above, you conclude that both inulin and glucagon regulate blood sugar. Insulin is a hormone produced in the pancreas by the islets of Langerhans, which normalizes the amount of glucose in the blood, while glucagon is a hormone produced in the pancreas that promotes the breakdown of glycogen into glucose in the liver.