Question

Curdling of milk in the stomach is due to the action of
A. Pepsin
B. Rennin
C. HCl
D. Renin

Answer 1

Hint: Curdling of milk is a process that happens in the gut of the animals that turns the liquid milk into a coagulated form so that the digestion of milk is improved.

Complete Answer:
Milk coagulation occurs in dairy plants which helps the plant stomach absorb the milk protein as the coagulation of milk lets it stay in the stomach for digestion for a longer time than usual. Enzymes which do this task convert the liquid milk into the coagulated form.

Let us analyze the options to find out the correct answer.
Option A: Pepsin is an endopeptidase that will break down protein into small peptides. It is the main enzyme of the human digestive system as it helps in the digestion of proteins. It is secreted by the chief cells of the stomach.Therefore, this is the incorrect option.

Option B: Rennin is also called chymotrypsin. It is a protease enzyme found in rennet. The chief cells of the animal's stomach produce this enzyme which helps in the coagulation of milk so that it stays in the gut for a longer time and its proteins can be absorbed efficiently. It converts the liquid milk into a semisolid form.Therefore, this is the correct option.

Option C: HCl (hydrochloric acid) is secreted in the stomach which provides an acidic environment in the stomach for the breakdown of food. It also removes bacteria in the stomach and thus helps in protecting our body from infection.Therefore, this is the incorrect option.

Option D: Renin is also called angiotensinogen. This enzyme is secreted by the kidneys and helps in maintaining the volume of extracellular fluid and arterial vasoconstriction.Therefore, this is the incorrect option.

Thus, the correct option is B) Rennin.

Note: Renin secretion is maximal during the first few days after birth which is declined afterwards. It helps in holding the milk in stomach for better digestion and absorption process