In this paper, we proposed a two-state model to quantitatively illustrate the working mechanism of caveolae structure in the regulation of cell membrane stretch. First, we derived the free energy compositions of one caveola in an arbitrary state. This model predicts two local minima for the free energy of one caveola at the completely open and completely closed states at the bottom of a relatively deep curve of free energy at different shape coefficients. The behavior of one caveola is generalized to large number of caveolae in cell membranes using the central limit theory. The dynamic stretching behavior of membrane during a constant-speed tether-pulling experiment is also investigated by making a hypothesis of transition rate between the closed and open states.

在本文中，我们提出了一个二态模型来定量说明细胞膜穴样凹陷结构在调节细胞膜拉伸中的工作机制。首先，我们推导出了任意状态下一个小窝的自由能组成。该模型预测了在不同形状系数的相对较深的自由能曲线底部处于完全打开和完全关闭状态的一个小窝的自由能的两个局部最小值。使用中心极限理论将一个小窝的行为推广到细胞膜中的大量小窝。还通过假设关闭和打开状态之间的转换率来研究膜在恒速拉绳实验期间的动态拉伸行为。