Premium
CMPARISON OF THE ACTION SPECTRA AND QUANTUM REQUIREMENTS FOR PHOTOSYNTHESIS AND PHOTOREDUCTION OF SCENEDESMUS *
Author(s) -
Bishop Norman I.
Publication year - 1967
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1967.tb08767.x
Subject(s) - action spectrum , photophosphorylation , photosystem i , photochemistry , photosynthesis , photosystem , photosystem ii , chemistry , quantum efficiency , wavelength , scenedesmus , physics , chloroplast , optoelectronics , botany , algae , biology , biochemistry , gene
‐The action spectrum and the quantum requirement of photoreduction (P.R) by hydrogen‐adapted Scenedesmus have been determined under conditions where photosystem II is inoperative. The action spectrum of P.R., when compared to that of photosynthesis, shows approximately a 20 nm shift in the long wavelength maxima and an apparent decreased utilization of light in the wavelength region 600–650 nm. The quantum requirement for P.R. is high at wavelengths below 650 nm and decreases to a minimum between 705–720 nm; the best value obtained was 10. These observations indicate that this process is exclusively a photosystem I reaction and furthermore offer additional evidence for a lack of appreciable transfer of excitation energy between the pigments of photosystems I and II. The relatively high requirement photophosphorylation or to the inadequacy of H 2 ‐hydrogenase system as the electron donor mechanism for photosystem I.