182 PLANT BASES [ch. xi 



Urease is quite specific in its action on urea, and the latter has been 

 detected in a few tissues which also yield the enzyme (grain of the 

 Wheat and seeds of the Bean) (Fosse, 4). 



Expt. 165. Action of urease on urea. To 100 c.c. of water in a small flask add 

 1 gm. of urea and 3 gms. of Soja Bean meal. Connect the flask by glass tubing to a 

 second flask contaning 0*5 c.c. of strong sulphuric acid in 50 c.c. of water and a piece 

 of litmus paper. Place the flask containing the urea and enzyme in a beaker of 

 water kept at 37-40° C. and run a rapid current of air through the two flasks. After 

 two or three hours, the litmus paper will turn blue. Add sodium carbonate to the 

 second flask and heat. Ammonia will be evolved and can be detected by its smell 

 and by giving white fumes with a drop of strong hydrochloric acid on a glass rod. 



EEFERENCES 



Books 



1. Abderhalden, E. Biochemisches Handlexikon, v. Berlin, 1911. 



2. Allen's Commercial Organic Analysis. Vegetable Alkaloids (G. Barger), 

 Vol. 7, 1913, pp. 1-94. 



3. Barger, G. The simpler Natural Bases. London, 1914. 



4. Fosse, R. Presence simultanee de Puree et de I'urease dans le meme vegetal 

 C. B. Acad. Sci., 1914, Vol. 158, pp. 1374-1376. 



5. Henry, T. A. The Plant Alkaloids. London, 1913. 



6. Jones, W. Nucleic Acids. London, 1920. 2nd. ed. 



7. Winterstein, E., und Trier, G. Die Alkaloide. Berlin, 1910. 



