Concentration upon the Optimum Temperature of a Ferment. 417 



Optimum Temperature. 



Optimum H + Concentration. 



(Physical Optimum.) 



i. Is independent of the concentration of 



the enzyme (Compton). 



Maltose, salicinase. 



ii. Is independent of the concentration of 



the substrate (Compton). 



Maltase, salicinase. 



iii. Is dependent on the H + concentration 



of the medium (Compton). 



Maltase. 



iv. Is dependent on the duration of the 



experiment serving to determine it 

 (Bertrand and Compton).* 



A mygdalinase, amygdalase. 



(Chemical Optimum.) 

 i. Ditto (Sorensen). 



Sue-rase. 



ii. Is dependent on the concentration of 



the substrate (Van Slyke and 

 Zacharias).t 



Urease. 



iii. Is dependent on the temperature of 



the experiment (O'Sullivan and 

 Tompson). 



Sucrose. 



iv. Ditto (Sorensen). 



Catalasc, pepsin, sucrose. 



v. Is dependent on the age of the enzymic 

 preparation (Bertrand and Comp- 

 ton).! 



Amygdalinase, amygdalase. 



* 'Comptes Bendus,' vol. 152, p. 1518 (1911). 

 t ' Journ. Biol. Chem.,' vol. 19, p. 205 (1914). 

 t 'Comptes Rendus,' vol. 159, p. 434 (1914). 



♦ 



