INFLUENCE OF TEMPERATURE UPON ENZYMES 213 



TIME REQUIRED TO LIQUEFY GELATIN HARDENED BY THYMOL, WITH 

 VARYING QUANTITIES OF TRYPSIN (MADSEN AND WALBUM.) 



F = Concentration t =Time required ' 



of Trypsin. in hours. Ft. 



0.105 0.5 0.052 



0.050 1.0 0.050 



0.027 2.0 0.054 



0.020 3.0 0.060 



0.015 4.0 0.060 



0.011 5.0 0.055 



0.009 6.0 0.054 



0.0072 8.0 0.058 



0.0060 10.0 0.060 



0.0037 16.0 0.059 



0.0032 18.0 O.C58 



0.0027 20.0 0.054 



0.0025 22.0 0.055 



0.0022 24.0 0.053 



COAGULATION OF MILK BY RENNET (MADSEN AND WALBUM). 



F = Concentration t =Time in 



of Rennet. minutes. Ft. 



8.00 4 32 



5.00 6 30 



3.30 9 30 



1.90 12 23 



1.30 20 26 



0.70 30 21 



0.70 35 25 



0.50 50 25 



0.40 70 28 



0.32 80 26 



0.28 100 28 



0.25 120 30 



0.185 180 33 



0.167 200 40 



THE INFLUENCE OF TEMPERATURE UPON ENZYMES. 



The general effect of increasing temperature upon the hydrolyzing 

 enzymes is to accelerate their action. This favorable influence is, 

 however, limited by the fact that after the temperature exceeds a 

 certain optimum the auto-inactivation of the enzyme, which always 

 takes place at a perceptible rate in enzyme-solutions, even at ordinary 

 temperatures, becomes so rapid as to more than counterbalance the 

 acceleration of its hydrolyzing action. The Optimum Temperature for 

 enzyme action was formerly supposed to be a characteristic of each 

 enzyme, distinguishing it more or less sharply from other enzymes. 

 We now recognize, however, that while in some measure the optimum 

 temperature does characterize certain groups of enzymes, yet it is 

 greatly influenced by a variety of factors other than the nature of the 

 enzyme itself, such as the reaction (acidity or alkalinity) of the medium 

 in which the enzyme is dissolved; the concentration of the enzyme itself 

 and the nature and concentration of the substrate upon which it is 

 acting. It is, of course, impossible to render all of these conditions 



