CONFORMATIONAL BASIS OF ENERGY TRANSDUCTION IN MEMBRANE SYSTEMS .V. MEASUREMENT OF CONFIGURATIONAL CHANGES BY LIGHT SCATTERING

Changes in the energy state of the cristal membrane of beef heart mitochondria can be followed continuously by light-scattering measurements at 90 ° to the incident beam. Only two of the three configurational transitions established by electron microscopy can be directly measured by the light-scattering technique. The correlation between the configurational changes deduced from the interpretation of electron micrographs, and the configurational changes implicit in the light-scattering measurements has been tested in a wide spectrum of experiments and found to hold in all cases. It has been concluded that the electron microscopic and light-scattering techniques both measure configurational change in the cristal membrane. The transition of cristae from the aggregated to the orthodox modality, and the oscillation of mitochondria between the energized uptake of K+ and swelling, and the de-energized release of K+ and shrinking, are phenomena which are readily analyzed by the method of light scattering in combination with that of electron microscopy. © 1969.