Horowitz Jordan M, Zhou Kevin, England Jeremy L
Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, 400 Technology Square, Cambridge, Massachusetts 02139, USA.
Phys Rev E. 2017 Apr;95(4-1):042102. doi: 10.1103/PhysRevE.95.042102. Epub 2017 Apr 4.
In the absence of external driving, a system exposed to thermal fluctuations will relax to equilibrium. However, the constant input of work makes it possible to counteract this relaxation and maintain the system in a nonequilibrium steady state. In this article, we use the stochastic thermodynamics of Markov jump processes to compute the minimum rate at which energy must be supplied and dissipated to maintain an arbitrary nonequilibrium distribution in a given energy landscape. This lower bound depends on two factors: the undriven probability current in the equilibrium state and the distance from thermal equilibrium of the target distribution. By showing the consequences of this result in a few simple examples, we suggest general implications for the required energetic costs of macromolecular repair and cytosolic protein localization.
在没有外部驱动的情况下,暴露于热涨落的系统会弛豫到平衡态。然而,持续的功输入使得抵消这种弛豫并将系统维持在非平衡稳态成为可能。在本文中,我们使用马尔可夫跳跃过程的随机热力学来计算为在给定能量景观中维持任意非平衡分布而必须供应和耗散能量的最小速率。这个下限取决于两个因素:平衡态下的无驱动概率流以及目标分布与热平衡的距离。通过在几个简单例子中展示这一结果的影响,我们提出了对大分子修复和胞质蛋白定位所需能量成本的一般启示。