Energy Transfer and Conservation in the Respiratory Chain 



617 



in detail and compared with the experimental data. A five-component 

 portion of the respiratory chain and three interaction sites have been repre- 

 sented by the analogue computer (Chance and Williams, 1956a) to demon- 

 strate crossover phenomena, respiratory control, and phosphorylation 

 efficiency. 



The response of the steady-state oxidation levels of the components to 

 different values of the intercarrier velocity constants is indicated in Table 1. 



Time (sec) 



Fig. 6. An analogue computer representation of a five-membered oxidative 

 phosphorylation chain with 3 interaction sites at cytochromes c, b and DPNH. 

 The top traces illustrate the overall properties of the system in terms of the 

 accelerated utilization of oxygen upon addition of ADP and the rate of utilization 

 of ADP. The lower traces represent the changes of steady state of the respiratory 

 carriers upon addition of ADP, a downward deflection representing an increased 

 reduction and an upward deflection indicating an increased oxidation. It is noted 

 that cytochrome c becomes more reduced and cytochrome b becomes more 

 oxidized : thus a crossover point between cytochromes b and c is demonstrated. 

 (AC-65) (Courtesy Advances in Enzymology) 



