297 



Fulvio Perini 



first 3-^ hours after illumination of the cell. After 8-12 hours 

 the well-known ratio. of 3-^00 molecules of chlorophyll/l molecule 

 of cytochrome c-552 ^ ' is established, and photo synthetic 

 processes proceed quite well. (See fig, h stnd 5«) 



20 40 



60 80 100 120 140 



Time(Hrs) 



o Chl./Cylo 552 

 o CW/Cylo 556 

 • 552m/j/558m^ 



2800 o 



o 



2400 ^ 



~C 



2000 ^ 



o 



O 



-1600 3 

 3 



1200 u, 



60 80 100 

 Time (Hrs ) 



120 140 



Fig. h. Kinetics of chlorophyll 

 and cytochrome c-552 formation 

 after Illumination of dark- 

 grown wild type Euglena gracilis 

 cells. 



Fig. 5« Relationship between 

 cytochromes c-552, 556 and 

 chlorophyll after illumination 

 of dark-grown wild-type cells. 



Cytochrome 55^ is present in all mutant strains of Euglena in 

 the same amoimt as the normal wild type on a cell basis (there 

 are slight differences on a weight basis). No change in cyto- 

 chrome 556 content was observed after illumination of etiolated 

 cells. A summary is given in Table 2. 



Cytochrome a-605 was detected in the mitochondria. 



No direct proof was obtained of the presence of cytochrome 

 b-561 in the chloroplasts, probably owing to the instability of 

 its prosthetic group. This cytochrome was found only in photo- 

 synthetic forms of Euglena . More than one flavoprotein has been 

 found in Euglena. These have been assigned to the succinoxidase. 



