530 Physik
Refine
Year of publication
- 2015 (6) (remove)
Document Type
- Article (6) (remove)
Keywords
- ageing (1)
- anomalous diffusion (1)
- biological physics (1)
- critical avalanche dynamics (1)
- gene regulatory networks (1)
- irreversible volume-change (1)
- irreversible work share (1)
- memory and delay (1)
- neuronal networks (1)
- physical chemistry (1)
- physics (1)
- reversible work share (1)
- reversible-share-theorem (1)
- stochastic models (1)
- stochastic processes (1)
- thermodynamics (1)
- total work (1)
Institute
Many chemical reactions in biological cells occur at very low concentrations of constituent molecules. Thus, transcriptional gene-regulation is often controlled by poorly expressed transcription-factors, such as E.coli lac repressor with few tens of copies. Here we study the effects of inherent concentration fluctuations of substrate-molecules on the seminal Michaelis-Menten scheme of biochemical reactions. We present a universal correction to the Michaelis-Menten equation for the reaction-rates. The relevance and validity of this correction for enzymatic reactions and intracellular gene-regulation is demonstrated. Our analytical theory and simulation results confirm that the proposed variance-corrected Michaelis-Menten equation predicts the rate of reactions with remarkable accuracy even in the presence of large non-equilibrium concentration fluctuations. The major advantage of our approach is that it involves only the mean and variance of the substrate-molecule concentration. Our theory is therefore accessible to experiments and not specific to the exact source of the concentration fluctuations.