Question

Choose the peptide hormone from the following
a. Adrenaline
b. Insulin
c. Testosterone
d. Progesterone

Answer 1

Hint: Peptide hormones or protein hormones are those hormones whose molecules are peptide or protein. These hormones are synthesized in endoplasmic reticulum from which they are transported to Golgi bodies and are packed to secretory vesicles for export. They function in growth, appetite and energy metabolism.

Complete answer:
Peptide hormones or protein hormones are those hormones whose molecules are peptide or protein. These hormones are synthesized in endoplasmic reticulum from which they are transported to Golgi bodies and are packed to secretory vesicles for export. Some examples of peptide hormones are ghrelin, calcitonin, insulin vasopressin, etc.

Thus, from the given options insulin is the peptide hormone. It is produced in pancreas by the beta cells of Langerhans, which is named after Paul Langerhan. Pancreas acts as both exocrine and endocrine gland. Insulin was discovered by Dr. Fredrick Banting and Charles Best.
• It is a polypeptide hormone.
• It regulates the metabolic activity of fats, carbohydrates, and proteins.
• It is also known as anabolic hormone.
• It is the first hormone to be isolated, purified and synthesized.
• It is the first hormone to be sequenced
• It is the first hormone to be produced by DNA technology.
• Chemical structure of insulin was given by Sanger. It contains 51 amino acids which are arranged in two polypeptide chains.

Action of insulin: increased levels of glucose in blood stimulates the cells of pancreas to increase insulin secretion in blood. The insulin circulates through the blood and takes up excess glucose from the blood. Similarly, when glucose level is low in the body, it inhibits the secretion of insulin.

Hence, the correct answer is option (B).

Note: Insulin has two types of disorders associated with it, Diabetes mellitus and Hyperinsulinism. Diabetes mellitus is a disorder characterized by increased levels of blood glucose and it affects multiple organs. It is further divided into two categories, type I and type II. Hyperinsulinism is the excess secretion insulin in blood.