Question

The master enzyme that ensures that most powerful digestive (hydrolytic) enzymes are NOT activated (proenzymes/zymogens) until they enter into the intestinal LUMEN (and not inside cells!) is

a. Pepsin

b. Trypsin

c.Chymotrypsin

d.Carboxypeptidase

d.Phospholipase

  

Answer 1

Pepsinogen is precursor for pepsin which is secreted in the stomach by the chief cells and it is activated by the HCl whcih is released from the parietal cells of stomach.

Trypsinogen is the precursor enzyme for trypsin which is secreted by the pancrease and trypsin is activated when trypsinogen reaches lumen of duodenum. Trypsin is the master enzyme responsible for activation of other pancreatic enzymes with exception of amylase.

Chymotrypsin, carboxypeptidase are the activated forms of chymotrypsinogen and procarboxypeptidases respectively which are produced by pancreas.

Answer is: Trypsin ( master enzyme)