24 ENZYME ACTION [CH. 



Expt. 17. Enzyme actions of an aqueous extract of zymin. Weigh out 2 gms. of 

 zymin and place them on a double folded filter-paper in a funnel and wash with 

 80 c.c. of distilled water. With the filtrate make the following experiments. 



(A) Action ofinvertase. (Harden and Zilva, 12.) Into two small flasks (a) and (6) 

 put the following : 



(a) 10 c.c. of a 2 % solution of pure cane-sugar + 10 c.c. of the filtrate from 

 zymin. 



(b) 10 c.c. of the same solution of cane-sugar + 10 c.c. of the boiled filtrate from 

 zymin. 



Put both flasks in an incubator at 38 0. After 30 minutes add equal quantities 

 (about 1-2 c.c.) of Fehling's solution to both test-tubes and boil (see p. 52). Tube (a) 

 will show considerable reduction of the Fehling. Tube (6) will show comparatively 

 little reduction, that which does take place probably being due to the sugar formed 

 by the action of glycogenase on stored glycogen. 



(B) Action of the glucoside-splitting enzyme. (Caldwell and Courtauld, 9 ; Henry 

 and Auld, 13.) This enzyme will act upon the glucoside, amygdalin, which is present 

 in bitter almonds, with the production of glucose, benzaldehyde and prussic acid 

 (see p. 145). Into two small flasks (a) and (6) put the following : 



(a) 20 c.c. of a 2 % solution of amygdalin + 20 c.c. of the filtrate from zymin. 



(b) 20 c.c. of the same solution of amygdalin + 20 c.c. of the boiled filtrate from 

 zymin. 



Add a few drops of toluol to both flasks and then cork, inserting, with the cork, 

 a strip of paper which has been dipped in solutions of picric acid and sodium 

 carbonate (see p. 146). Put both flasks in an incubator at 38 C. for 12-24 hours. The 

 picrate paper in flask () will have reddened. Add a little Fehling's solution to the 

 liquid in the same flask and boil. The Fehling will be reduced. The liquid in flask 

 (b) will only reduce Fehling slightly [see Expt. A (6)] and the picrate paper will not 

 be reddened. 



REFERENCES 

 BOOKS 







1. Abderhalden, B. Biochemisches Handlexikou, v. Berlin, 1911. 



2. Bayliss, W. M. The Nature of Enzyme Action. London, 1919. 4th ed. 



3. Euler, H. General Chemistry of the Enzymes. Translated by T. H. Pope. 

 New York and London, 1912. 



4. Harden, A. Alcoholic Fermentation. London, 1914. 2nd ed. 



5. Vernon, H. M. Intracellular Enzymes. London, 1908. 



6. Wohlgemuth, J. Grundriss der Fermentmethoden. Berlin, 1913. 



PAPERS 



7. Armstrong, H. B., and Armstrong, E. P. The Origin of Osmotic Effects. 

 III. The Function of Hormones in Stimulating Enzymic Change in Relation to 

 Narcosis and the Phenomena of Degenerative and Regenerative Change in Living 

 Structures. Proc. R. Soc., 1910, B Vol. 82, pp. 588-602. Ibid. IV. Note on the 

 Differential Septa in Plants with reference to the Translocation of Nutritive Materials. 

 Proc. R. Soc., 1912, B Vol. 84, pp. 226-229. 



