238 



LIGHT AND LIFE 



Emission Spectra 



Fig. 17 shows the true emission spectrum of the firefly light reaction 

 in vitro in glycyl-glycine buffer at pH 7.6 (24) . The relative spectral 

 photon sensitivity oi the phototube used is also included in the figure, 

 and the observed spectrum was corrected for phototube sensitivity. 

 The peak emission for the bioluminescence is 562 millimicrons, with 

 the band ranging from 500 millimicrons to 630 millimicrons. Cer- 

 tainly, as an absolute minimum, the energy requirement for the 

 bioluminescence should therefore exceed 57 kcal/mole. 



500 



550 



600 



650 



m 



V- 



lig. 17. F.mission spectrum of fircny light in xitro. Bioluminescence (solid cir- 

 cles) in glycvl glycine biillei at fM 7.0. The peak and emission is at ,'if)2 m^. Super- 

 imposed upon this emission specliinn is the normali/ed photon spectral efliciency 

 of the photocathode of the phototube used in the (luantum yield measurements. 



