OF MITOCHONDRIA 



substrates, thus forming water). Each step, as indicated in the diagram below, involves both oxidation and 

 diphosphate (ADP) and inorganic phosphate (Pi), by coupling with the various phosphorylating enzyme systems. This 

 components of the respiratory chain. Up to three molecules of ATP may be synthesized per molecule of DPNH 



Flavin 



--^,^ 2 cyt-b 



\/ (Fe+++) 



I Dehydrogenases'* | 



ivin-H? — ^ N» 



• Flav 



2 cyt-b 

 (Fe++) 



BAL- sensitive 

 6 factor^ 



1 



2 cyt-b ^ 111 cyt-C| 



(Fe++) V (Fe++) 



2 cyt-b 

 (Fe+++) 



' 2 cyt-cr 

 (Fe++^^) 



■ 2 cyt-c 

 (Fe+++") 



Ferro- cytochrome- c 

 oxidase system 



2 cyt-a 

 {Fe+++) 



HzO 



I •-'2 



Phosphorylating 



System II: 

 ADP+ Pi — ATP 



Phosphorylating 



System III: 

 ADP+Pi — ATP 



nucleotide) and TPN (triphosphopyridine nucleotide) are commonly used abbreviations for Coenzyme 1 and Coenzyme 

 arrow indicates that reduced DPN arising by transhydrogenase action eventually may pool with reduced DPN formed 

 dehydrogenase of the respiratory chain. /5/ The dotted arrows indicate that the reduced flavoprotein may either 

 prosthetic group of cytochrome b, which is part of the respiratory chain. /7/ Slater has shown that a factor which 

 with cytochrome- c. ( 4] This may be identical with a factor which is sensitive to low concentrations of Antimycin 



G. R., 

 1952. 



Holmes, W. F.. and Higgins, J., ibid 217:439, 1955. [3] Slater, E. C. Chem. wbl., Arast. 53:180, 1957. 



127 



