Question

Trypsinogen is an inactive enzyme secreted by the pancreas. It is activated by
A. Pepsin of stomach
B. Chymotrypsin
C. Bile
D. Enterokinase

Answer 1

Hint: Trypsinogen is an inactive enzyme secreted from pancreas that is converted into an active enzyme trypsin. Trypsin is responsible for the hydrolysis of proteins, peptones and proteoses into the dipeptides. This hydrolysis takes place in the small intestine.

Complete Answer:
Trypsinogen is an inactive pancreatic enzyme which gets activated by an enzyme enterokinase secreted by the intestinal mucosa into active trypsin. The enzyme trypsin in turn activates other enzymes present in the pancreatic juice.

Apart from trypsinogen; chymotrypsinogen, procarboxypeptidase, amylases, lipases and nucleases are also secreted. Chymotrypsinogen and procarboxypeptidase are also released in inactive form which are activated into chymotrypsin, carboxypeptidase.

The correct option is D i.e. enterokinase.

Additional information: There are various reactions that take place in the small intestine by the help of the enzymes present in the pancreatic juice. Such reactions are responsible for the conversion of the complex biomolecules into the simpler, soluble form that can be easily absorbed by the body.
These reactions include:
1. Conversion of proteins, peptones and proteoses into dipeptides by the help of enzyme trypsin, chymotrypsin, carboxypeptidases.
2. Conversion of polysaccharide (starch) into disaccharides by the help of enzyme amylase.
3. Conversion of fats into diglycerides that are further converted into monoglyceride by the help of the enzyme lipases.
4. Conversion of nucleic acids into nucleotides and nucleosides by the help of enzyme nucleases.

Note: The enzymes secreted from pancreatic juice work on the alkaline pH. The product of the above reactions are further broken down into the end products by the help of the enzymes present in succus entericus. The end product forms are absorbed in the ileum and jejunum regions of the small intestine.