Kinetics Studies on the Fluorescence Quencher in Isolated Chloroplasts

Cation effects on the fluorescence of isolated chloroplasts.

At room temperature, the fluorescence of chloroplasts in vivo and in vitro originates nearly exclusively from the chlorophyll of the oxygen evolving system II of the photosynthetic apparatus. The yield and the kinetics of this light emission are closely coupled to the primary photochemical events of photosystem II. Fluorescence studies, therefore, have contributed much to our knowledge about th...

On the mechanism of the energy-dependent quenching of atebrin fluorescence in isolated chloroplasts.

Recently, a very interesting observation relating energy generation to the quenching of the fluorescence of the uncoupler atebrin in isolated chloroplasts has been described by Kraayenhof [ 11. It was shown that the required energy could be provided by electron transport, ATP hydrolysis or a pH gradient, and it was therefore suggested that the extent of quenching may be used to measure the ‘ene...

Light-induced changes of NADPH fluorescence in isolated chloroplasts: a spectral and fluorescence lifetime study.

Isolated chloroplasts show a light-induced reversible increase in blue-green fluorescence (BGF), which is only dependent on NADPH changes. In the present communication, we report a time-resolved and spectral analysis of this BGF in reconstituted chloroplasts and intact isolated chloroplasts, in the dark and under actinic illumination. From these measurements we deduced the contribution of the d...

Fluorescence Quenching at High Quencher Concentrations

Isolated Chloroplasts

1. Chloroplasts prepared by the non-aqueous technique will, after fragmentation by ultrasonic treatment, incorporate [2-14C]mevalonic acid into phytoene, the first C40 compound formed in the biosynthetic sequence to coloured carotenoids. 2. With suspensions containing 3*5mg. of chlorophyll, the optimum amounts of cofactor required were ATP (10,umoles), magnesium chloride (20,umoles) and glutath...