MARTIN KLINGENBERG 



the respiratory chain and on the overall electron transport, i.e. the oxygen up- 

 take, in the presence of succinate or glycerolphosphate (15). Both cytochrome 

 h and flavoprotein (Fig. 5), in the presence of succinate or glycerolphos- 



468-490m/i 



^E = 

 0005 

 cm-' 



Flavoprotein 

 reduction 



434-490m/i 



0010 

 cm ' 



Cyt.b I 

 reduction I 



Fig. 5. The reducing effect of ATP on flavoprotein and cytochrome h in the 

 presence of succinate or glycerol- 1 -phosphate (cf. legend Fig. 2). 



phate are further reduced on the addition of ATP. The degree of reduction 

 of cytochrome b increases from about io"o in the presence of substrate 

 alone to 40% after the addition of ATP. Cytochrome c, as shown both with 



550-S4lm/x 



00025 



Cyt. c 

 reduction 



Fig. 6. The oxidizing effect of ATP on cytochrome c in the presence of 

 glycerol- 1 -phosphate and succinate (cf. legend Fig. 2). 



glycerolphosphate and succinate (Fig. 6) is however rapidly oxidized by 

 addition of ATP. The degree of reduction of cytochrome c decreases from 

 i2°o to about 5 to 8%. Also cytochrome a is oxidized by addition of ATP 

 (Fig. 7). In this experiment a low concentration of azide has been added 

 in order to increase the reduction of cytochrome a and afterwards the 



