论文标题
活性随机力促进细菌细胞质的扩散
Active random force promotes diffusion in bacterial cytoplasm
论文作者
论文摘要
实验发现，代谢活性细胞的扩散速度要比休眠细胞，尤其是大颗粒的扩散速度要快得多。然而，这种依赖大小的扩散增强的机制尚不清楚。在这项工作中，我们将代谢过程作为白色活性力的净效应近似，并模拟具有高度多分散粒径分布的细菌细胞质模型系统。我们发现，相对于休眠细胞的活性细胞的扩散增强对于大颗粒而言可能更为实质。我们的模拟与大肠杆菌的实验数据定量一致，这表明活性力与粒子半径多数成比例的自相关函数。我们证明，这种白噪声活性力等效于大约0.57 Pn的活性力，随机取向。我们的工作揭示了活细胞内随机过程的新兴简化。
Experiments have found that diffusion in metabolically active cells is much faster than in dormant cells, especially for large particles. However, the mechanism of this size-dependent diffusion enhancement in living cells is still unclear. In this work, we approximate the net effect of metabolic processes as a white-noise active force and simulate a model system of bacterial cytoplasm with a highly polydisperse particle size distribution. We find that diffusion enhancement in active cells relative to dormant cells can be more substantial for large particles. Our simulations agree quantitatively with the experimental data of Escherichia coli, suggesting an autocorrelation function of the active force proportional to the cube of particle radius. We demonstrate that such a white-noise active force is equivalent to an active force of about 0.57 pN with random orientation. Our work unveils an emergent simplicity of random processes inside living cells.
