Is a constant low-entropy process at the root of glycolytic oscillations?

Abstract

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.

Coupled Response of Membrane Hydration with Oscillating Metabolism in Live Cells: An Alternative Way to Modulate Structural Aspects of Biological Membranes?

“…These observations call into question the idea that intracellular water acts as a mere passive biological solvent, as implicitly understood in the standard membrane-based model of the cell. In a subsequent study, we observed that cell volume, heat flux, and temperature also oscillated synchronously with glycolytic oscillations, showing a strong coupling of these physical properties with the biochemical pathway [14]. These results were consistent with a recently proposed thermodynamic formalism where isentropic thermodynamic systems can display coupled oscillations in all extensive and intensive variables, reminiscent of adiabatic waves [16].…”

“…They also support 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. We argue that all of these experimental results [12,13,14,15], which are difficult to rationalize under the dominant view of the cell, are in line with the association-induction hypothesis (AIH) [17,18,19]. This theory, which still remains unrefuted, offers an alternative conceptual approach based on well-established principles of colloidal physical chemistry to explain how emergent features of the intracellular environment may give rise to cellular function.…”

“…In a series of papers [12,13,14,15], we reported a number of key observations that challenge some basic tenets of the established view of cellular systems. Particularly, we observed that during glycolytic oscillations, the extent of dipolar relaxation in the cellular interior, which is governed mainly by the rotational dynamics of intracellular water, is coupled to the behavior of the pathway (intervening metabolites such as ATP and NADH) in that it oscillates synchronously [12,13].…”

On a Simple General Principle of Brain Organization

“…Taken together, these observations suggest that conscious awareness—that is, brain interacting with the environment—brings brain dynamics close to a “healthy” equilibrium with some, albeit small, dissipation needed to establish communication channels between cell networks. This situation in brain dynamics being close to equilibrium and of low dissipation may find its parallel in the case of biochemical oscillations; for instance, glycolytic oscillations in cells have been shown to be in near-equilibrium conditions with low dissipation so that small energy inputs can sustain the oscillatory, metabolic regimes (Thoke et al, 2018). These observations challenge the common view of metabolism being highly dissipative, and possibly this notion can be generalized to other biological processes operating in near-equilibrium regimes, like cognition.…”

Temporal metabolic partitioning of the yeast and protist cellular networks: the cell is a global scale-invariant (fractal or self-similar) multioscillator

“…One wonders what he would have made of a very recent paper on glycolytic oscillations as a means of maintenance of low entropy in living systems. 142…”