194 PHYSIOLOGICAL CHEMISTRY 



tract. Keep the tubes at 4oC. and observe any change which may occur. 

 What is the result and how do you explain it? Write the equation for the reac- 

 tion which has taken place. 



EXPERIMENTS ON PANCREATIC RENNIN 



' Prepare four test-tubes as follows : 



(a) 5 c.c. of milk -h 10 drops of neutral pancreatic extract. 



(b) 5 c.c. of milk+2o drops of neutral pancreatic extract. 



(c) 5 c.c. of milk+io drops of alkaline pancreatic extract. 



(d) 5 c.c. of milk+2O drops of alkaline pancreatic extract. 



Place the tubes at 6o-65C. for a half hour without shaking. Note the 

 formation of a clot. 1 How does the action of pancreatic rennin compare with the 

 action of the gastric rennin? 



1 This reaction will not always succeed, owing to conditions which are not well under- 

 stood. 



