The The Mechanism of Diffusion of Ions across a Phase Boundary and through Cell Walls.
The The Mechanism of Diffusion of Ions across a Phase Boundary and through Cell Walls.
复制标题
离子穿过相界和细胞壁的扩散机制。
DOI：
10.1021/j150476a003
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发表时间：
1950
期刊：
影响因子：
--
通讯作者：
J. Davies
中科院分区：
文献类型：
--
作者：
J. Davies
尽管物质穿过活细胞质膜的扩散问题已研究多年，但对于扩散速率差异很大的原因以及扩散速率与细胞壁结构的关系，仍存在相当大的争议。由于已知离子的扩散通常是逆浓度梯度进行的，而且通常比非电解质的扩散慢得多，因此，在解释非电解质的渗透率数据方面，也许不可避免地取得了更多的进展，这些数据包括油水分配系数、分子大小、分子量、极性、温度，在某些情况下还包括细胞壁的孔径。工作的Collander和奥弗顿必须特别指出，在这方面（16，19，22，46，50，55）。即使在最有利的扩散条件下，当我们考虑一种非离子溶质（如柠檬酸三乙酯（16）），它在油相中和水相中的溶解度相等时，其扩散常数也比在水中小100，000倍。大多数扩散电解质和非电解质穿过细胞壁的扩散速率仍然较低。
Although the problem of the diffusion of material across the plasma membrane of a living cell has been studied for many years, there is still considerable con-troversy over the cause of thewidely differing diffusion rates and correlation of these with a picture of the structure of the cell wall. Since the diffusion of ions is known to proceed often against concentration gradients and is frequently much slower than that of nonelectrolytes, it is perhaps inevitable that more progress has been made in interpreting the permeability figures of the latter in terms of oil-water partition coefficients, molecular size, molecular weight, polarity, tempera-ture, and, in some cases, also the pore diameter of the cell wall. The work of Collander and of Overton must be specially noted in this connection (16, 19, 22, 46, 50, 55). Even under the most favorable conditions for diffusion, when we con-sider a nonionic solute (eg, triethyl citrate (16)), equally soluble in the oil and in the aqueous phases, the diffusion constant is about 100,000 times smaller than that inwater. Most diffusing electrolytes and nonelectrolytes have still lower diffusion rates across the cell wall.