FUNCTION OF FLAVOENZYMES IN ELECTRON TRANSPORT I43 



TABLE III 



ESTERIFICATION OF PHOSPHATE DURING THE OxiDATION 



OF Substrate in the Presence of Amytal and \"itamix Kg 



(Conover and Ernster unpublished) 



Experimental conditions as in Table II. Substrates were added in a final 

 concentration of o-oi M. 



The antimycin A-sensitivity of the Yitamin Ky-induced respiration in 

 the amytal-blocked system indicated that the electrons mediated by 

 vitamin K3 may enter the respiratory chain at the level of cytochrome b. 

 This point could be tested with the double-beam spectrophotometer, 



400- 



300- 



200 



434- 490 m// 

 cyt. b 

 reduction 



Jf=00lcm' 



Fig. I. Effect of amytal and vitamin Kj on the oxygen consumption and on the 

 reduction of cytochrome c during the oxidation of glutamate (Conover and 

 Ernster, unpublished). The medium contained 001 m triethanolamine buffer, 

 pH 7-4, o-oi M Pj, pH 74, 0004 .M MgCL, 0065 M KCl, and o-i M sucrose. 

 Mitochondria from 200 mg. rat liver were used. The amounts of additions were as 

 follows: 2-0 /amoles L-glutamate, o-8 /^mole ADP, 2-0 /imoles amytal, and 0-04 

 ^mole vitamin K3. Final volume, i -2 ml. Temperature, 25 ^ 



