Question

Insulin production and its action in the human body are responsible for the level of diabetes. This compound belongs to which of the following categories:
A. A coenzyme
B. A hormone
C. An enzyme
D. An antibiotic

Answer 1

Hint: Insulin is a protein that maintains blood sugar level in the human body and is produced in the pancreas. From its functions, we can determine if it is a coenzyme or hormone or enzyme or antibiotic.

Complete step-by-step answer:
Insulin is a peptide hormone produced in the human body by the pancreas.
Pancreas is an endocrine gland and its secretions are called hormones, which are transported to different organs by blood. Hormones in general regulate physiology and activities such as digestion, excretion, metabolism, growth, stress induction and movement.
Insulin is secreted by the beta cells of islets of Langerhans. It is a very important hormone, as it regulates the metabolism of carbohydrates, proteins and fats. It induces the absorption of glucose into liver and skeletal muscle cells, where they are either converted to glycogen by glycogenesis or into fats by lipogenesis. High concentration of insulin in the blood, inhibits glucose production and secretion, thereby reducing blood sugar level.
A deficiency of insulin, results in diabetes mellitus, a condition of high blood sugar level.

Hence, option B is the correct answer.

Note: A coenzyme is essential for the activity of an enzyme, as it assists biochemical transformations. Insulin does not assist any biochemical transformation. Hence option A is incorrect.
An enzyme catalyzes chemical reactions in the body. Insulin induces the absorption of glucose by the liver, but it does not take part in glycogenesis or lipogenesis. Hence, option C is incorrect.
An antibiotic inhibits the growth of or destroys microorganisms. Insulin has no such function. Hence option D is incorrect.