The Quantum Efficiency of Photosynthesis 



87 



PROTOCOL No. 3 

 Comparison of the yield in carbonate-bicarbonate mixtures and in culture medium 



Experiment of VI-1-49. 20° C. 630 — 660 m/t. Three vessels, in each 7 ml cell Suspension, 

 containing 200 /d of cells. Cultures centrifuged, then washed once in, and taken up in, carbonate- 

 bicarbonate mixture. Intensity 5.4 /d O? per minute. 



I. Vessel No. 7. 

 V = 13.824 ml 

 Vf = 7.00 ml 

 ko 2 = 0.657 



Gas space air. Solution 85 parts M/10 NaHC0 3 

 tion point with white ligin. 



15 parts M/10 K2CO3; pH 9.2. At compensa- 



15.4 /d 



II. Vessels Nos. 3 and 5, containing 7 ml culture medium, pH 4.9, with 200 //l of cells each. 

 Cultures centrifuged, then washed once in, and taken up in, fresh culture medium. Gas Space 

 5% CO2 in air. Mirror shifted every 10' from one vessel to the other; actinometer 5.4 /d O2 per 

 minute for red light. 



III. Vessel No. 7, with same cells as before but without white light (below compensation-point). 

 pH 9.2 



10' dark — 33.5 mm 

 10' red light — 23.5 mm 

 10' dark — 30.5 mm 

 10' red light — 22.5 mm 

 10' dark — 30.0 mm 

 20' dark — 60.5 mm 



20' dark 62.7 mm, 20' red light — 46.0 mm 



Light action 20' 62.7 — 46 = + 16.7 mm = 11 /d 



1 20 • 5.4 



~ 11 



9.8 



