A SEPARATION OF THE REACTIONS IN PHOTOSYNTHESIS BY MEANS OF INTERMITTENT LIGHT

摘要: Experiments on photosynthesis in intermittent light have been made two occasions. Brown and Escombe, 1905, use of a rotating sector to study the effect intensity leaves. They found three-quarters from given source could be cut out each revolution without decreasing rate photosynthesis. Willstatter (1918, p. 240) explains that this was probably due low concentration carbon dioxide available for The short periods would sufficient reduce all which reach cells by diffusion during dark periods. In 1919-20 Warburg experiments Chlorella similar those Escombe Instead stating his results as amount per total elapsed time, did, he gave time were illuminated. Since used sectors half incident revolution, illuminated always an experiment. Working with high dioxide, reduced more when allowed fall intermittently than them continuously. improvement yield over continuous depended frequency flashing. With four minute 10 cent, 8000 it 100 cent. Warburg proposed alternative explanations light. Either reduction continues dark, or proceeds twice fast brief flash same length He considers latter explanation likely, assumes certain steps photosynthetic process continue until equilibrium is reached. After period find higher reactive substance ready light, able decomposition equal The described paper indicate, we think, proceed involve what has hitherto known Blackman reaction. Probably not completed photochemical part process. A correct way representing sequence events follows. Two are involved dioxide: reaction absorbed, followed requiring -- so called If capable proceeding at great speed, but can go no faster We suppose product formed converted some other reaction, chlorophyll set free take again green cell illuminated, think rapidly its formed. only Blackmail removes intermediate product. now darkened, stops once, raw material, exhausted. nothing further happens Higher efficiency obtained if lasted long enough build up product, allow present moment ended. In Warburg's flicker length. work done increased shortening both This indicates too maximum efficiency. must brought down near speed Using 133 flashes second, cent yield. improve 300 400 using 50 second making much shorter opened possibility determining necessary complete removal duration. Lengthening should there removed before next flash. describe show about 0.03 0.4 depending temperature. Further characteristics reactions taking place dark.