IRREVERSIBLE MONOLINEAR CHAINS 



333 



crease of K.2 by the factor 1 + (I)/^, (see Eq. 3-12), from Eq. 7-3 it is found 

 that the increase in (B) due to inhibition is simply given by: 



(B) + K, 



(7-8) 



and hence, in contrast to noncompetitive inhibition, is not dependent on 

 any of the parameters of the uninhibited enzyme system. In terms of 

 the inhibition of Eg: 



(B). = 



(B) 

 1 - I 



i(B) 



K, 



(7-9) 



lOOmM 



(I) 



Fig. 7-8. Variation of the over-all inhibition with the concentration of an inhibitor 



of E2 in a monoHnear chain. Curve 1: V1/V2 = 10; curve 2: VJV^ = 3; curve 3: Fj/Fj 



= 1; curve 4: VJV^ = 0.33; curve 5: VJV^ = 0.1. 



into which the vakie of (B) from Eq. 7-3 may be substituted. In Fig. 7-9 

 it is seen that (B)^ rises more slowly with increasing inhibition for compet- 

 itive inhibition than for noncompetitive inhibition. More interesting is 

 the fact that the system does not pass out of the steady state whatever 

 the inhibition on Eg or the inhibitor concentration. Thus theoretically a 

 competitive inhibitor acting on Eg will never reduce the rate of formation 

 of C. This mav also be seen from the fact that the rate of reaction 2 is: 



dt 



F.(B), 



(B), 



K. 



01 

 K, 



(7-10) 



and substitution of (B), from Eq. 7-8 shows d{C)!dt to be unchanged from 

 the uninhibited state. The reason for this is that (B), can rise to sufficient 



