VOL. 4 (1950) 



QUANTUM EFFICIENXY OF PHOTOSYNTHESIS 



341 



{Equation 3) Action of light in 20; X02 = H' —;■ 



k', 



C02"k'02 



Quantum efficiency for Og, 

 Quantum efiiciencv for CO, 



^C02 = 



20-5.07 



k'c02+ yk'o2 



I.II-X02= +3 



= 20. 2- 1.62 = + 32.1 

 -I. II = —36.4 



32.8 ^ 



2O-5-07 

 36.4 



3-1 

 2.8 



PROTOCOL No. 2 



Experiment of V-30-4g. 20° C. 630-660 va.^. 5°o CO, in air. 270 /il of cells per vessel. 

 Experiment I. Alternately dark and light each 10'. Actinometer for the red light (total) 5.4 jil 

 O, per minute. \^Tien vessel No. 5 was dark, No. 3 was illuminated and vice versa. 



Experiment II: Both vessels were now constantly illuminated with a loo-watt incandescent 

 lamp of nonmeasured* light intensity and red light of measured intensity added for alternating 

 periods of 5'. Actinometer for the red light (total) 5.4 /d O^ per minute. 



No. 3 

 5' white + 14.0 mm 5' white + red + 15.0 mm 



+ 14-0 

 + 12.5 

 + 14-0 



+ II-5 

 + 12.0 



+ 16.5 

 + 16.5 

 + 14.0 



+ 15-0 

 + 14-5 



25' white + 87.5 mm 25' white + red + 110 

 25': H' = no — 87.5 = + 22.5 mm 



30' white + 78 mm 30' white + red +91.5 mm 

 30': H = 91.5 — 78 = + 13.5 mm 

 25': H = II. 3 mm 



Calculation of quantum efficiency for experiment I (Dark ± Red) 



In 60': H + 31.5 mm H' + 59 mm 

 Applying equations (i) and (2), protocol (i) 



In 60' X02I = + 70-4 /^l \ CO, 



\ y ^= ? 



XCO2 = —56.0 H\ I °2 



J_ _ 60-5.4 



rp 70.4 



T 6n • ^ f 



5-8 



= —0.8 



Ouantum efficiencv for O^, 



Quantum efficiency for COg, — = 



4.6 



S6 



Calculation of quantum efficiency for experiment II (White 



In 25': H + II-3 mm H' + 22.5 mm 



Applying equations (i) and (2), protocol (i) 



Red) 



In 25' X02 = + 30-3 fjl 



XC02 = —27.2 /d 

 Quantum efficiency for O. 





fp 



CO, 



"a 



- = — 0.90 



25'5-4 



Quantum efficiency for CO,, — = 



<P 



30.3 

 25-5-4 



= 4-5 



But kept constant by a 500-watt voltage regulator. 

 References p. 346. 



