All are true regarding activation of trypsin, EXCEPT:
Trypsin is a proteolytic enzyme, secreted by the pancreas. It is secreted in the inactive form trypsinogen. It is activated to the active form, trypsin in the small intestine. Its activation is brought about by enterokinase, autocatalytically by trypsin and calcium is also required. Ref: Ganong's Review of Medical Physiology, 22nd Edition, Page 468
Enterokinase helps in the activation
Activated autocatalytically by trypsin
It takes place in the small intestine
Mg is also required