Thoke Henrik Seir, Olsen Lars F, Duelund Lars, Stock R P, Heimburg Thomas, Bagatolli Luis A
MEMPHYS - International and Interdisciplinary Research Network, Odense M, Denmark.
University of Southern Denmark, Institute for Biochemistry and Molecular Biology, Campusvej 55, 5230, Odense M, Denmark.
J Biol Phys. 2018 Sep;44(3):419-431. doi: 10.1007/s10867-018-9499-2. Epub 2018 May 24.
We measured temporal oscillations in thermodynamic variables such as temperature, heat flux, and cellular volume in suspensions of non-dividing yeast cells which exhibit temporal glycolytic oscillations. Oscillations in these variables have the same frequency as oscillations in the activity of intracellular metabolites, suggesting strong coupling between them. These results can be interpreted in light of a recently proposed theoretical formalism in which isentropic thermodynamic systems can display coupled oscillations in all extensive and intensive variables, reminiscent of adiabatic waves. This interpretation suggests that oscillations may be a consequence of the requirement of living cells for a constant low-entropy state while simultaneously performing biochemical transformations, i.e., remaining metabolically active. This hypothesis, which is in line with the view of the cellular interior as a highly structured and near equilibrium system where energy inputs can be low and sustain regular oscillatory regimes, calls into question the notion that metabolic processes are essentially dissipative.
我们测量了处于非分裂状态的酵母细胞悬浮液中温度、热通量和细胞体积等热力学变量的时间振荡，这些酵母细胞呈现出时间性糖酵解振荡。这些变量的振荡与细胞内代谢物活性的振荡频率相同，表明它们之间存在强耦合。这些结果可以根据最近提出的一种理论形式来解释，在该理论中，等熵热力学系统可以在所有广延变量和强度变量中显示耦合振荡，这让人联想到绝热波。这种解释表明，振荡可能是活细胞在进行生化转化（即保持代谢活性）的同时需要恒定低熵状态的结果。这一假设与将细胞内部视为高度结构化且接近平衡的系统的观点一致，在该系统中能量输入可以很低并维持规则的振荡状态，这对代谢过程本质上是耗散的这一观念提出了质疑。
