Summary
Pancreatic hormones that lower and raise blood sugar.
In depth
Beta cells in islets release insulin; alpha cells release glucagon. They oppose each other, maintaining blood glucose. Insulin was discovered by Banting and Best in 1921.
Insulin lowers blood glucose; glucagon raises it. Both are peptide hormones. Type 1 diabetes involves insulin deficiency.
Key idea: the pair maintains a steady glucose level.
These antagonistic pancreatic hormones keep blood glucose at about 4 to 6 mmol per litre. After a meal, rising glucose causes beta cells of the islets of Langerhans to release insulin, which promotes uptake of glucose into muscle and fat cells (via GLUT4), conversion to glycogen in liver and muscle, and fat synthesis, lowering blood glucose.
When glucose falls, alpha cells release glucagon, which stimulates the liver to break down glycogen and make glucose by gluconeogenesis, raising blood sugar. This is classic negative feedback. In type 1 diabetes, beta cells are destroyed by autoimmunity; in type 2, cells become resistant to insulin.
Example: people with type 1 diabetes inject insulin.
Key idea: the pair balance each other.
Frequently asked questions
What is Insulin and Glucagon?
Pancreatic hormones that lower and raise blood sugar.
Which area of biology covers Insulin and Glucagon, and how advanced is it?
Insulin and Glucagon is one of the 54 topics in Reproduction & Endocrinology. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Negative Feedback in Endocrine Control, Growth Hormone, Hormones.
Can you give an example of Insulin and Glucagon?
Injection of insulin is required in type 1 diabetes.
What should I learn before Insulin and Glucagon?
Insulin and Glucagon is a Beginner topic, so no earlier topic is required. Other Beginner topics in Reproduction & Endocrinology that pair well with it include Reproduction, Asexual Reproduction, Sexual Reproduction.
What topics are related to Insulin and Glucagon?
The closest topics to Insulin and Glucagon are Negative Feedback in Endocrine Control, Growth Hormone, Hormones, Adrenal Cortex Hormones. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Insulin and Glucagon?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Insulin and Glucagon. To practise the whole of Reproduction & Endocrinology, use the Reproduction & Endocrinology quiz.
How is Insulin and Glucagon different from Negative Feedback in Endocrine Control?
Insulin and Glucagon: Pancreatic hormones that lower and raise blood sugar. Negative Feedback in Endocrine Control: Rising hormone levels inhibit further secretion, as with thyroxine and TSH. Read both side by side and note what each one explains.
How should I study Insulin and Glucagon step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Negative Feedback in Endocrine Control and explain the difference aloud. Finally, take the Reproduction & Endocrinology quiz and come back to this page for any question you miss.