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The Regulation of Cellular Systems

TLDR
The basic equations of metabolic control analysis are rewritten in terms of co-response coefficients and internal response coefficients to describe the interaction of optimization methods and the interrelation with evolution.
Abstract
Introduction Fundamentals of biochemical modeling Balance equations Rate laws Generalized mass-action kinetics Various enzyme kinetic rate laws Thermodynamic flow-force relationships Power-law approximation Steady states of biochemical networks General considerations Stable and unstable steady states Multiple steady states Metabolic oscillations Background Mathematical conditions for oscillations Glycolytic oscillations Models of intracellular calcium oscillations A simple three-variable model with only monomolecular and bimolecular reactions Possible physiological significance of oscillations Stoichiometric analysis Conservation relations Linear dependencies between the rows of the stoichiometry matrix Non-negative flux vectors Elementary flux modes Thermodynamic aspects A generalized Wegscheider condition Strictly detailed balanced subnetworks Onsager's reciprocity reactions for coupled enyme reactions Time hierarchy in metabolism Time constants The quasi-steady-state approximation The Rapid equilibrium approximation Modal analysis Metabolic control analysis Basic definitions A systematic approach Theorems of metabolic control analysis Summation theorems Connectivity theorems Calculation of control coefficients using the theorems Geometrical interpretation Control analysis of various systems General remarks Elasticity coefficients for specific rate laws Control coefficients for simple hypothetical pathways Unbranched chains A branched system Control of erythrocyte energy metabolism The reaction system Basic model Interplay of ATP production and ATP consumption Glycolytic energy metabolism and osmotic states A simple model of oxidative phosphorylation A three-step model of serine biosynthesis Time-dependent control coefficients Are control coefficients always parameter independent? Posing the problem A system without conserved moieties A system with a conserved moiety A system including dynamic channeling Normalized versus non-normalized coefficients Analysis in terms of variables other than steady-state concentrations and fluxes General analysis Concentration ratios and free-energy-differences as state variables Entropy production as response variable Control of transient times Control of oscillations A second-order approach A quantitative approach to metabolic regulations Co-response coefficients Fluctuations of internal variables versus parameter perturbations Internal response coefficients Rephrasing the basic equations of metabolic control analysis in terms of co-response coefficients and internal response coefficients Control within and between subsystems Modular approach Overall elasticities Overall control coefficients Flux control insusceptibility Control exerted by elementary steps in enzyme catalysis Control analysis of metabolic channeling Comparison of metabolic control analysis and power-law formalism Computational aspects Application of optimization methods and the interrelation with evolution Optimization of the catalytic properties of single enzymes Basic assumptions Optimal values of elementary rate constants Optimal Michaelis constants Optimization of multienzyme systems Maximization of steady-state flux Influence of osmotic constraints and minimization of intermediate concentrations Minimization of transient times Optimal stoichiometries.

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The geometry of biological time , by A. T. Winfree. Pp 544. DM68. Corrected Second Printing 1990. ISBN 3-540-52528-9 (Springer)

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COPASI---a COmplex PAthway SImulator

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Complete nitrification by Nitrospira bacteria

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Analysis of optimality in natural and perturbed metabolic networks

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References
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Journal ArticleDOI

A generalization of Wegscheider's condition. Implications for properties of steady states and for quasi-steady-state approximation

TL;DR: In this paper, a generalized Wegscheider condition for equilibrium constants in chemically reacting systems is formulated, which is then proved to be a necessary and sufficient condition for detailed balancing, and the existence, uniqueness, and global asymptotic stability of equilibrium states for reaction systems endowed with generalized man action kinetics are proved.
Journal ArticleDOI

Control analysis of time-dependent metabolic systems†

TL;DR: It is proved that simultaneous changes in all enzyme concentrations by the same arbitrary factor, is equivalent to a change in the time scale, which leads to the derivation of general summation theorems that link control and time coefficients.
Journal ArticleDOI

The effect of natural selection on enzymic catalysis

TL;DR: Analysis of the free energy changes in enzyme catalysis shows that maximum rates at low enzyme concentrations are attained for enzymes with Michaelis constants close to the concentrations of their substrates in vivo.
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Determining all extreme semi-positive conservation relations in chemical reaction systems: a test criterion for conservativity

TL;DR: In this article, an algorithm for deciding whether a chemical reaction system is conservative is given, based on the difference of the number of reacting species and the rank of the stoichiometric matrix, and it is shown that conservativity is a necessary and sufficient condition that an atomic stoichiometry satisfying mass conservation can be found.
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Frequency encoded biochemical regulation is more accurate than amplitude dependent control

TL;DR: This paper demonstrates how the same arguments can be applied to biochemical control networks and shows that the conversion of an analogue demand signal to an oscillation is stable against corruption by noise in the input and even against Corruption by certain internal chaotic motions.