ACTION SPECTRA FOR THE ABSORBANCE CHANGE AT 880 nm AND FOR P870 FLUORESCENCE FROM A PHOTOSYNTHETIC REACTION CENTER*

Photosynthetic reaction centers isolated from blue‐green mutant strain R‐26 of Rhodopseudomonas spheroides were used to study the action spectra for the light‐induced absorption changes at 880 nm, and for the P870 fluorescence. These spectra indicated that a pigment, possibly bacteriopheophytin, with an absorption maximum at 757 nm is an intrinsic component of the reaction center and transfers energy to P870 with relatively high efficiency.