60 LABORATORY WORK IN PHYSIOLOGICAL CHEMISTRY. 



AMYLOLYSIS. 



Amylopsin is stronger in its action than ptyalin; other- 

 wise the conditions which influence its activity are practically 

 the same as the salivary diastase. 



Make use of the glycerol or alcoholic extract of the pan- 

 creas. 



To 10 c.c. of starch paste add 5 c.c. of pancreatic extract 

 and place in the water-bath at 40 C. Test from time to 

 time with the iodine solution as you did under Salivary 

 Digestion. Do you get an achromic point? Finally test for 

 a reducing sugar. What is the character of this? 



LIPOLYSIS. 



Steapsin is the least stable of all the pancreatic enzymes, 

 and is particularly sensitive to the action of acids, being 

 destroyed easily by all except the higher fatty acids. 



Its action on neutral fats tends toward a breaking down 

 of the fat molecule into fatty acids and glycerol. 



For the following experiments use the alkaline glycerol 

 extract of the gland. 



(a) To 10 c.c. of "litmus milk" add 5 c.c. of the pan- 

 creatic extract. Place the test-tube in the water-bath at 

 40 C. What is the cause of the change which takes place? 



(6) Repeat experiment (a) with the exception that 

 boiled pancreatic extract is used. Note any change? 



(c) Instead of "litmus milk," try the experiment with 

 neutral ethyl butyrate. What is the equation for the reac- 

 tion which takes place? 



