生物受器上的量測不準度

Abstract

生物大分子無時無刻處在外界環境的擾動下，如熱擾動及雜訊。假如此分子有多個狀態，在達到平衡時，處在各狀態的比例是個機率分布。在此我們研究多階(狀態)系統在外噪聲干擾下，此比例偏離最大機率的變異數(variance)，假如這個大分子是細胞膜上偵測訊號分子的受器，此variance即為受器的量測不準度。本文推導多階系統的量測不準度，並跟慣用的等效低階模型的不準度做比較，討論的環境擾動包括白噪聲、不同相關函數的色噪聲，以及deterministic的微擾。

Biological molecule is perturbed by the external environment at all time, such as thermal fluctuation and noise. If the molecule has multiple states, the proportion of these states is a probability distribution when the system reaches equilibrium. Here we discuss the variance of the probability distribution of the multi-state system under external noise, and if the biological molecule is just the receptor on the membrane, the variance is the measurement uncertainty of the receptor. We derive the measurement uncertainty of multi-state system, and compare with the uncertainty of the equivalent lower-state model we used to use. The environmental noises include white noise, colored noise with varied correlation functions, and deterministic perturbations.