ENZYME-SUBSTRATE COMPOUNDS 



Pushing 

 Block 



Substrate 

 syringe 



Substrate 



Stopcock for 

 refilling _ 

 substrate 

 syringe 



Potentiometer for 

 flow velocity 



Air vent 



Driving 

 syrings 



Mixing chamber 

 Observation chamber 



Stopping 

 syringe 



Stop 



c ^ 

 Fig. 6. An apparatus for measuring the time sequence of oxidation of the 

 components of the mitochondrial respiratory chain (24). 



Since a series of oxidations and reductions of the mitochondria can be 

 carried out repetitively in this apparatus because exhaustion of the added 

 oxygen occurs automatically with a respiratory system, the mitochondria can 

 be used for a series of oxidations and reductions, and the apparatus is so ar- 

 ranged to take advantage of this. Volume of the "enzyme" syringe is 80 

 ml., 1 ml. for the "substrate" syringe. Mixing time is less than 5 millisec. 

 Satisfactory records can be obtained with cytochrome concentrations of less 

 than 1 fxM (FA 21). 



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