280 Discussion 



represents the Ki of the cytochrome-c-cytochrome oxidase inhibited complex. This 

 is rather amusing because this K^ has often been taken to be the dissociation constant 

 of the Michaelis-Menten enzyme-substrate complex. The inhibition by cytochrome c 

 of cytochrome c oxidase can account for the rectangular hyperbolic relationship 

 between cytochrome c concentration and oxidase activity, and the first order kinetics 

 found by Smith on the basis of the following simple mechanism written formally: 



where ESj is the active complex and ESh is the inhibited complex. 



k^KiC 



where ^ = concentration of cytochrome c, and e = concentration of cytochrome c 

 oxidase, i.e. 



Kmax = k^K^e 



Km — f^i- 



