Chapter 9: Reaction Mechanisms, Pathways, Bioreactions and Bioreactors
Professional Reference Shelf
Example R9.63: Derive a Rate Law for a Multiple Substrate System
Derive the rate law for this sequence assuming that the rate of reaction
between the (ADHNADH)
complex and acetaldehyde is rate limiting. 

Solution  
Assuming that the reaction between the cofactorenzyme complex and acetaldehyde is rate limiting, the rate law is  


[Note: k_{2}=k_{2}
(h^{+}).] After applying the PSSH
to (ES_{2})
and (E) to obtain the equations 

(RE7.43.1) (RE7.43.2) 

we add Equations (RE7.43.1) and (RE7.43.2) and rearrange to obtain  
(RE7.43.3) (RE7.43.4)  
The total enzyme concentration is again constant at (E_{t}):  
(RE7.43.5) (RE7.43.6)  
After solving Equation (RE7.43.6) for E, we combine with Equation (RE7.43.1) to obtain the rate law:  
(RE7.43.7)  
Setting P_{2} = 0 and rearranging, we obtain the initial rate law:  

(RE7.43.8)  
where  
