專題演講 Seminar

2023/01/11(Wed)     10:00 -11:00    視訊會議室(圖書館) 3F, Video Conference Room(Library)

Title

Exponential growth and metabolic dynamics in biophysical systems: from theoretical frameworks to single-cell experiments

Speaker

林暐翔博士 (ChEM-H Institute, Stanford University)

Dr. Wei-Hsiang Lin (ChEM-H Institute, Stanford University)

Abstract

Biophysical systems, which are capable to grow and respond to environmental change, are typically nonlinear and non-equilibrium. The principles for how these systems control their energy, material fluxes and maintain their stability are largely open in physics. I will present two research projects in this talk:

(i) Theoretical frameworks for exponential growth: physical systems with different scaling laws grow at different modes. Biophysical systems (such as cells and ecosystems) often exhibit exponential growth in the long-term, while the underlying scaling property have not been described. I will discuss how nonlinear scaling of reaction fluxes is related with exponential growth. In addition, I will discuss a new way to analyze biomass fluxes in reaction network with delay differential equations, which enables us to calculate exponential growth rate in frequency domain.

(ii) Single-cell measurements of ATP dynamics: ATP (adenosine triphosphate) is the common energy carrier for all living systems and is essential for cell metabolism and RNA synthesis. Using microfluidic cell culture with ATP fluorescence biosensor, I measured the long-term ATP dynamics for E. coli cells for multiple days. I found that intracellular ATP level is coupled with bacterial cell cycle, and the ATP oscillation is attenuated in the absence of overflow metabolism. I also found that ATP homeostasis is correlated with single-cell growth, where cell cycles with smaller ATP fluctuation grow and divide faster on average.

Language

演講語言 (Language): in English