Trypsinogen $\stackrel{\mathrm{X}}{\to }$ Trypsin

Chymotrypsinogen $\stackrel{\mathrm{Y}}{\to }$Chymotrypsin

In the equation given above, X and Y are

Trypsinogen $\stackrel{\mathrm{Enterokiase}}{\to }$ Trypsin

Chymotrypsinogen $\stackrel{\mathrm{Trypsin}}{\to }$ Chymotrypsin

Brush border enzyme enterokinase activates the protease (trypsin) of pancreatic juice. Trypsin in turn activates other proteases (chymotrypsinogen and procarboxypeptidase) of pancreatic juice.