Studies on the kinetics of cation-associated fluorescence changes in chloroplast membranes.

Here we present an analysis of the kinetics of cation effects on chlorophyll fluorescence yield in an attempt to distinguish between these various possibilities.
The main finding we report is that the fluorescence decline which occurs on EDTA addition to the chloroplast membranes incubated in the presence of Mg 2÷ can be explained adequately by second-order reaction kinetics involving two different substrates in
an environment in which one of the substrates is present in two kinetically distinguishable 'subpopulations'.