Question

Glucagon produced by alpha cells of islets of Langerhans,
a) Converts glucose to glycogen
b) Converts glycogen to glucose
c) Decreases the concentration of glucose in the blood
d) None of the above

Answer 1

Glucagon is a peptide hormone. Which is secreted from the $\alpha$ cells of islets of Langerhans in the pancreas. It increases blood sugar level by acting on hepatocytes and stimulates the breakdown of glucagon and synthesis of glucose.

Complete step by step answer:
Islets of Langerhans, irregularly shaped patches of endocrine tissue located within the pancreas of most vertebrates which is responsible for the production and release of hormones that regulate glucose levels. It consists of four distinct cell types, of which three (alpha, beta, and delta cells) produce important hormones; the fourth component (C cells) function is not yet known.
- Glucagon is responsible for controlling blood sugar levels in the body. Glucagon animates the transformation of put away glycogen (put away in the liver) to glucose, which can be delivered into the circulation system. This cycle is called glycogenolysis.
So, the correct answer is ‘convert glycogen to glucose’.

Additional information: The alpha cells of the islets of Langerhans produce a restricting hormone. i.e, glucagon, which is liable for the arrival of glucose from the liver and unsaturated fats from fat tissue. where, glucose and free unsaturated fats favor insulin deliver and restrain glucagon discharge. Glucagon promotes the production of glucose from amino acid molecules. This process is called gluconeogenesis. It decreases glucose utilization by the liver so that however much glucose as could reasonably be expected can be emitted into the circulatory system to keep up blood glucose levels.

Note: Glucagon also acts on adipose tissue to stimulate the breakdown of fat stores into the bloodstreams. If a person consumes too much glucagon a rare tumor of the pancreas called a glucagonoma can secrete excessive quantities of glucagon. This can cause diabetes mellitus, weight loss, thrombosis, and a characteristic skin rash.