We review the effects of molecular crowding on solute diffusion in solution and in cellular aqueous compartments and membranes. Anomalous diffusion, in which mean squared displacement does not increase linearly with time, is predicted in simulations of solute diffusion in media crowded with fixed or mobile obstacles, or when solute diffusion is restricted or accelerated by a variety of geometric or active transport processes. Experimental measurements of solute diffusion in solutions and cellular aqueous compartments, however, generally show Brownian diffusion. In cell membranes, there are examples of both Brownian and anomalous diffusion, with the latter likely produced by lipid-protein and protein-protein interactions. We conclude that the notion of universally anomalous diffusion in cells as a consequence of molecular crowding is not correct and that slowing of diffusion in cells is less marked than has been generally assumed.

中文翻译：

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拥挤对溶液和细胞扩散的影响。

我们审查了分子拥挤对溶质扩散在溶液中以及在细胞水室和膜中的影响。在模拟固定或移动障碍物拥挤的介质中的溶质扩散，或者当溶质扩散受到各种几何或主动传输过程的限制或加速时，可以预测异常扩散，其中均方位移不会随时间线性增加。然而，溶质在溶液和细胞水隔室中扩散的实验测量通常显示出布朗扩散。在细胞膜中，既有布朗扩散又有异常扩散的例子，后者可能是由脂蛋白和蛋白质相互作用引起的。