What is glucagon?

Glucagon is a peptide hormone released from pancreatic alpha cells in response to low blood glucose levels. It inhibits insulin (hormone produced by pancreatic beta cells) which wants to move glucose out of the blood into the cells, which would only serve to further decrease blood glucose levels. It also stimulates hepatic gluconeogenesis (synthesis of glucose by the liver) and glycogenolysis (breaking down glycogen to create more glucose, occurring in muscle and liver cells).

Glucagon is one of a number of hormones responsible for glucose homeostasis - the maintenance of stable blood glucose levels in the body. In response to falling blood glucose levels, glucagon in released from alpha cells located in the pancreas. Glucagon travels through the bloodstream to the liver, where it attaches to receptors found on the cell membranes of hepatocytes (liver cells). What follows is a sequence of intracellular events, resulting in the breakdown of glycogen (the storage form of glucose) into glucose, which is released from the cell into the bloodstream. As a result, blood glucose levels rise and homeostasis is restored.

Glucagon is a hormone released by the pancreas that works in the liver to convert glycogen to glucose.

Glucagon is a hormone produced in the pancreas. In many ways it has the opposite effect of insulin. Glucagon increases the amount of glucose in the bloodstream which means that more glucose is available for respiration. Glucagon increase blood glucose levels by causing the hydrolysis (breakdown) of glycogen (a storage polymer of glucose) in to free glucose molecules.

The endocrine system controls blood glucose concentration using two hormones; insulin and GLUCAGON. Whilst insulin acts to lower blood glucose concentration if it is too high, Glucagon does the opposite, and works to raise blood glucose concentration if is becomes too low. It does this in the following key ways:

1) Glucagon decreases the rate of respiration, meaning less glucose is required.

2) Glucagon binds to specific receptors on the cell membranes of liver cells and activates

-enzymes which break glycogen in to glucose (called GLYCOGENOLYSIS)

-enzymes involved in the formation of glucose from glycerol and amino acids (called GLUCONEOGENSIS)

As you can see here, there are many key words beginning with the letter 'G' and sounding similar. A frequent mistake people make it to get them confused, and you won't get the mark in an exam if they are spelt incorrectly.

Make sure you know the definitions/spellings and difference between GLUCOSE, GLYCOGEN, GLUCAGON, GLYCOGENSIS, GLYCOGENOLYSIS, GLUCONEOGENSIS

A way to help with this is to look at the etymology of the words themselves:

GLYCOGENSIS- 'Glyco' relates to Glycogen, 'genesis' meaning 'origin or formation'. So this word literally means 'the formation of Glycogen'.

GLYCOGENOLYSIS- The first part of the word is 'Glycogen', and the second part 'lysis' means to 'break something down'. So this word literally means 'the breakdown of Glycogen'.

GLUCONEOGENSIS- 'Gluco' relates to Glucose, 'neo' means new, and 'genesis' again means 'origin or formation'. So, this work literally means the formation of new glucose (from glycogen).

If you are ever stuck in an exam, if you unpick the words, this will hopefully help you to remember which is which!

Glucagon is a hormone produced by alpha cells in the islets of Langerhans tissues of the pancreas. Glucagon acts to increase blood glucose concentrations by stimulating the conversion of glycogen to glucose in the liver and gluconeogenesis.

Glucagon is a peptide based hormone released by the alpha cells of the islets of the pancreas. It is an antagonist to insulin. It is released when a decrease in blood glucose levels is detected and it works to increase blood sugar levels by increasing gluconeogenesis and glycogenolysis in the liver.

A hormone released by the pancreas to help achieve homeostasis involving the body's glucose levels , it stimulates both glycogenolysis and gluconeogenesis.

Glucagon is a hormone produced by the pancreas, specifically by alpha cells in the islets of Langerhans. It plays a crucial role in regulating blood sugar levels in the body. When blood glucose levels are low, such as during fasting or between meals, glucagon is released into the bloodstream.

The primary function of glucagon is to raise blood glucose levels by stimulating the liver to convert stored glycogen into glucose through a process called glycogenolysis. Glucagon also promotes gluconeogenesis, which is the synthesis of glucose from non-carbohydrate sources like amino acids and glycerol.

In addition to its role in glucose metabolism, glucagon can also have effects on other metabolic processes, such as promoting the breakdown of fats (lipolysis) and stimulating the release of ketone bodies from the liver.

Overall, glucagon acts as a counter-regulatory hormone to insulin, helping to maintain glucose homeostasis in the body by increasing blood sugar levels when they fall too low.

Glucagon is a hormone released from the alpha- cells in the pancreas, it aids in the regulation of your blood glucose levels.

Glucagon is a hormone produced by the alpha cells of the pancreas. It breaks down glycogen stores to raise the concentration of glucose.

Thanks for your question Orie.

Glucagon is a hormone that is involved in controlling blood sugar (glucose) levels. It is produced by the alpha cells, found in the islets of Langerhans, in the pancreas, from where it is released into the bloodstream.

Glucagon works in tandem with insulin in order to regulate (maintain homeostatic balance). Insulin helps to move glucose out of the blood stream, say after a meal containing carbohydrates, and into cells throughout the body. Glucagon can then be used during period of fasting (not eating for a period of 4hours or more) in order to break down stored glucose and move it back into the blood stream. We want to try and maintain our circulating blood glucose concentrations at around 4.5 to 5.5 mmol/L throughout the day.

glucagon is a hormone produce by the alpha cells in the pancreas. It breaks down glycogen into glucose to increase glucose levels in the body when it is too low.

Hi Orie

Glucagon is a hormone formed in the pancreas. It is released in response to low blood glucose levels which may occur after periods of exercise.

Glucagon has three main functions:

• Stimulates the liver to break down glycogen into glucose, which is then released into the blood.
• The breakdown of triglycerides into fatty acids.
• The process of gluconeogenesis, this is the conversion of amino acids into glucose.

Glucagon is a hormone that is involved in controlling blood sugar (glucose) levels. It is produced by the alpha cells, found in the islets of Langerhans, in the pancreas, from where it is released into the bloodstream.

So what is the action of glucagon? The pancreas detects low blood glucose concentration and this may happen if you haven't eaten for a while. Alpha cells in the pancreas secrete glucagon. Glucagon (1st messenger) travels in the bloodstream and binds with complimentary glycoprotein receptors on liver cells to form a hormone receptor complex (HRC). HRC causes a membrane bound enzyme to change in tertiary structure and the active site consequently becomes complementary to ATP. ATP is then converted to cAMP (2nd messenger) (Adenylate cyclase catalyses the cyclization of ATP to cAMP. cAMP activates protein enzyme kinase which converts glycogen to glucose. Glucose moves out of the cell by facilitated diffusion and the blood glucose concentration goes back to normal. This is an example of negative feedback.