Question

How does pepsinogen change into its active form?

Answer 1

Hint: Pepsinogen is inactive form and converted into active form pepsin by the action of HCl, prorenin is also inactive form which is converted by HCl into renin, which acts on milk protein called casein. Both enzymes are secreted by the zymogenic cell.

Complete answer:
Pepsinogen is the proenzyme which is secreted by the chief cell or peptic cells also called as zymogenic cells which are basal in location. HCl is the main responsible component of gastric juice which convert the proenzyme called pepsinogen into pepsin, once pepsinogen converted into pepsin and pepsin is self capable to convert itself into pepsin, this pepsin enzyme help in digestion of protein molecule of food. Pepsin converts the complex protein molecules into the simpler molecules like proteases and peptones. Which are joined by peptide bonds. Pepsin even digest collagens of connective tissue fiber not keratin of hair, horn and nails. It is a proteolytic enzyme of the stomach.
Pepsinogen are grouped in 5 different group which are based on its primary structure, pepsinogen A also known as pepsinogen I, pepsinogen B, progastricsin also known as pepsinogen II and pepsinogen C, prochymosin also called prorennin and pepsinogen F also called pregnancy-associated glycoprotein.
Pepsin is mostly active in pH between 1.5 to 2.5 acidic environments and temperature between 37 degree Celsius to 47 degree Celsius. Pepsin is the primary cause of damage of the mucosal membrane of the stomach which produces mucus which protects the stomach lining when HCl acts on pepsinogen. Pepsin may be inhibited by inhibitor compounds and by high pH. Pepstatin is a potent inhibitor of pepsin, which is a low molecular weight compound.

Note: Pepsinogen and prorennin are the two proenzyme which are secreted by the chief cells pepsinogen convert into pepsin by the action of HCl which digest the protein and prorennin convert into renin by the action of HCl which convert milk protein casein to paracasein.