Calcium Uptake by Rat Kidney Mitochondria

Abstract

have to be 10-15 seconds. A reasonable figure for the collision broadening of the excited level would be given by r ' 1013 sec1. Since the chlorophyl molecules are thought to be arranged in a monomolecular layer. we let n = 2, then t, 2 X 10-3. n2 Therefore the condition for convergence of the perturbation series is by no means fulfilled, and in order to get a valid approximation, one would have to solve the secular equation. which would lead to nonlocalized states. Further work in this direction is in progress.The above considerations hold also for more extensive systems. It seems possible that they can be applied to biological processes other than photosynthesis. For example, excitation processes in the retina could be mentioned. The light wave focused on one visual rod is coherent within the area of this rod. It s:ems probable that this collective character of the excitation is important for the formation of the signal in the adjoining nervous system. It also seems possible that collective activities play a role in the function of the central nervous system and relations may be found, say, between conscience and nonlocalized electronic states, or S and storage of memory.

Ion Uptake by Soybean Root Tissue Depleted of Calcium by Ethylenediaminetetraacetic Acid

“…Hence, the amount of cation bound within and without some exchange barrier (probably the outer cell membrane) can be deuced to be a function of metabolism involving high energy phosphate. Recent reports showing increased Ca binding in mitochondria at the expense of ATP are of interest in this respect (2,3,6,24 (20). In the important respects we have confirmed his observations on the effects of ultraviolet light and ribonuclease.…”

NCLX Protein, but Not LETM1, Mediates Mitochondrial Ca2+ Extrusion, Thereby Limiting Ca2+-induced NAD(P)H Production and Modulating Matrix Redox State

“…To achieve such tight regulation, cells are equipped with a number of proteins mediating the transport of Ca 2ϩ across the plasma membrane, the endoplasmic reticulum, and the inner mitochondrial membrane (1). Mitochondria contribute to the shaping of Ca 2ϩ signals through Ca 2ϩ uptake and release (2)(3)(4)(5)(6)(7)(8)(9). At the same time, the associated [Ca 2ϩ ] mt 3 transients act as signals to stimulate energy metabolism.…”

Effect of Active Accumulation of Calcium and Phosphate Ions on the Structure of Rat Liver Mitochondria

“…The "active" or respiration-linked accumulation of Ca ++ from the suspending medium by isolated mitochondria, first demonstrated by Vasington and Murphy (1,2), has been studied in some detail in a number of recent investigations (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11). The accumulation of Ca ++ during respiration has been found to be quite massive, attaining values as high as 3.0/~moles Ca++ per mg mitochondrial protein (2)(3)(4)(5)(6).…”