Question

The protein present in milk is
A. Casein
B. Glutelin
C. Myosin
D. Globulin

Answer 1

This protein is found in the mammalian milk. It is a family of related phosphoproteins. Rennin is found only in infants for the digestion of milk protein. The action of rennin is overtaken by the pepsin enzyme in adults.

Complete answer:
Hydrochloric acid maintains a strongly acidic pH of about 1.8. HCl changes over pepsinogen and prorenin into pepsin and rennin individually. Pepsin shows autocatalytic action.

Rennin is present only in the infants which helps in digestion of milk protein casein and its action is overtaken by pepsin in adults. Casein is a phosphoprotein, regularly found in mammalian milk. Sheep and buffalo milk have the highest casein content than any other types of milk. Casein is a major component of cheese (as a free additive).

Casein provides amino acids, carbohydrates, calcium and phosphorus. Glutelin is found in the endosperm of seeds of the grass family. Myosin is found in muscle. It is a polymerized protein, many monomeric proteins meromyosin constitute one thick filament. Globulins is a globular protein, produced in the liver. Globulins, albumins, fibrinogen are blood components.

So, the correct answer is option A.

Note: Digestion of proteins take place in the small intestine. Pancreatic juice contains protease proenzymes: trypsinogen, chymotrypsinogen and procarboxy-peptidase and enzymes- elastase. Proteins, proteoses, peptones that reach the intestine are acted upon by proteolytic enzymes of the pancreatic juice. Intestinal juice contains enterokinase, aminopeptidases dipeptidases. Enterokinase converts trypsinogen of pancreatic juice into trypsin.