INTRODUCTION AND THEORETICAL CONSIDERATIONS 



453 



such circumstances the slope and the intercept are increased by a factor 

 of 1 + [I]/K I} as compared to the linear relationship in the absence of the 

 inhibitor. 



For the specific case of noncompetitive inhibition ("uncompetitive in- 



1/[S] 



Figure 2. Relationship of the reciprocal of the rate of a biological process to the 



reciprocal of the substrate concentration. 

 _._._._. Relationship in the absence of an inhibitor. 

 Relationship in the presence of a competitive inhibitor at a defined 



concentration. 

 mmwwmhp- Maximum rate of the biological process at optimal substrate con- 

 centrations. 

 Extrapolated theoretical values for rate exceeding the maximum rate 



of the biological process which is then limited by other enzymatic 



processes. 

 Maximum value of 1/[S] for biological systems either synthesizing or 



containing unknown amounts of substrate. 

 x x x x x x x Maximum value of the reciprocal of rate of the biological process for 



systems synthesizing or containing unknown amounts of substrate 



under experimental conditions. 

 -x-x-x-x Extension of theoretical relationships for biological systems incapable 



of synthesis of substrate or not containing unknown amounts of 



substrate, 

 hibition") in which the inhibitor combines only with the enzyme-substrate 

 complex, addition of the inhibitor does not change the slope as compared 

 to the linear relationship in the absence of inhibitor; but the intercept 

 increases by a factor of 1 + [I]/K 8I . 



These changes are indicated in Figure 1, which illustrates the varia- 



