[sam01]

A young boy presents with failure to thrive. Biochemical analysis of a duodenal aspirate after a meal reveals a deficiency of enteropeptidase (enterokinase). The levels of which of the following digestive enzymes would be affected?

A. Amylase
B. Colipase
C. Lactase
D. Pepsin
E. Trypsin

 

[khanar]

The correct answer is E

Enteropeptidase is an enzyme produced by cells in the duodenum wall whenever ingested protein enters the duodenum from the stomach. Enteropeptidase has the critical job of turning trypsinogen (a zymogen) to trypsin.
Trypsin (AKA Endopeptidase) activates the conversion of chymotrypsinogen to chymotripsin and procarboxypeptidase to carboxypeptidase (exopeptidase).

These names are always confusing:
Enterokinas, Enteropeptidase, Endopeptidase, and Exopeptidase.

 

[Seetal]

ahh PEPTIDASE!!! yes enteropeptidase threw me off completely!

sigh.. i shouldve tried harder.

u're absolutely ryte. peptidase converts trypsinogen to trypsin.

 

[sam01]

u re right guys.Good explanation RRmadukha. Enteropeptidase, formerly called enterokinase, activates trypsinogen by limited proteolytic digestion to give trypsin. Trypsin is itself capable of activating trypsinogen, which produces a positive feedback effect. Trypsin also activates chymotrypsinogen (and several other proteolytic enzymes), so deficiency of enteropeptidase results in a severe deficiency of enzymes that digest protein