ENZYMES. 63 



sugar cannot be expressed by the above formula. 1 Recent investigations 

 of HUDSON 2 show, however, that the inversion of cane-sugar by enzyme 

 is a monomolecular reaction. The varying results of earlier investiga- 

 tors depend upon a disturbing action of the multirotation of the dextrose. 

 These results have been confirmed by EULER. S 



The second law for catalytic reactions which we have formulated 

 that with constant quantities of substrate the reaction velocity is propor- 

 tional to the quantity of enzyme, has been shown in certain cases where 

 the substrate was in excess (practically constant quantity) namely with 

 kephir lactase, 4 trypsin with casein as substrate. 5 In the just-mentioned 

 monomolecular enzyme reactions the velocity coefficient in a few cases was 

 found proportional to the quantity of enzyme (hsemase, 6 erepsin with 

 glycyl-glycine as substrate, 7 pancreatic lipase 8 ) and in others not (catalase 

 from Boletus scaber, 9 lipase from pig fat) 9 . It has been shown for several 

 enzymotic reactions that with the same substrate the same decomposi- 

 tion can be obtained if the time of action varies in inverse proportion to 

 the added quantity of enzyme. If p is the quantity of enzyme and 

 t the time of action, then the decomposition is the same in all tests where 

 p.t is the same figure. This rule has been found true for the following 

 enzymes : invertin (O'SuLLiVAN and THOMPSON under certain conditions 10 ), 

 pepsin (SJOQVIST n ), rennin (especially FULD 12 ), peptone-splitting enzyme 

 (VERNON 13 ), fibrin ferment of snake poison (MARTIN 14 ), trypsin (HEDIN IS ), 

 pepsin, rennin, trypsin, pyocyaneus protease (MADSEN 16 ). On the 

 action of trypsin upon casein this law has been shown correct for different 

 stages in the reaction. 17 This indicates that the progress of the entire 

 reaction remains the same with different quantities of enzyme, only 

 that the time for the same decomposition is inversely as the quantity 



1 Henri, Zeitschr. f. physik. Chem., 39, 194, 1901; Brown, Trans. Chem. Soc., 

 81, 373, 1902. 



2 Journ. Amer. Chem. Soc., 1908. 



3 Pflanzen Chemie, Braunschweig, 1908, 80. 



4 Armstrong, Proc. Roy. Soc., 73, 500, 1904. 



5 Hedin, Journ. of Physiol., 32, 471, 1905. 



8 Senter, Zeitschr. f. physik. Chem., 44, 257, 1903. 



7 Euler, Zeitschr. f. physiol. Chem., 51, 213, 1907. 



8 Kastle and Loevenhart, Amer. Chem. Journ., 24, 491, 1900. 



9 Euler, Hofmeister's Beitrage, 7, 1, 1906. 



10 Trans. Chem. soc., 57, 926, 1890. 



11 Skand. Arch. f. Physiol., 5, 358, 1895. 



12 Hofmeister's Beitrage, 2, 169, 1902. 



13 Journ. of Physiol., 30, 334, 1903. 



14 Ibid., 32, 207, 1905. 



15 Ibid., 32, 468, 1905; 34, 370, 1906. 



16 Arrhenius, Immunochemie, Leipzig, 1907, 46. 



17 Journ. of Physiol., 32, 468, 1905; 34, 370, 1906. 



