Metabolism Energy Thermodynamics

How are specific pathways constructed from individual reactions A pathway must satisfy minimally two criteria (1) the individual reactions must be specific and (2) the entire set of reactions that constitute the pathway must be thermodynamically favored. A reaction that is specific will yield only one particular product or set of products from its reactants. As discussed in Chapter 8. a function of enzymes is to provide this specificity. The thermodynamics of metabolism is most readily approached in terms of free energy, which was discussed in Sections 1.3.3. 8.2.1, and 8.2.2. 

Reductants for chemoautotrophs are generally deep in the Earth s crust. Vent fluids are produced in magma chambers connected to the Atheno-sphere. As such, the supply of vent fluids is virtually unlimited. While the chemical disequili-bria between vent fluids and bulk seawater provides a sufficient thermodynamic gradient to continuously support chemoautotrophic metabolism in the contemporary ocean, in the early Earth the oceans would not have had a sufficiently large thermodynamic energy potential to support a pandemic outbreak of chemoautotrophy. 

Westerhoff, H.V. and Van Dam, K. (1984) Mosaic Non-Equilibrium Thermodynamics of (the Control of) Energy Metabolism. Elsevier, Amsterdam, in the press. 

CHAPTER 5 Thermodynamics, Chemical Kinetics, and Energy Metabolism... 

Storage of energy thermodynamics free energy chemical equilibria and group transfer potential, acid-base balance, disorders of energy metabolism, e.g., mitochondrial myopathies, diabetic ketoacidosis 107-108, 230-268, 318, 412... 

However, much research remains to be done in this area. The thermodynamics of metabolic flux analysis has not yet been well established and free energy loss analysis based on metabolic flux analysis has only been applied to some particular problems, although there might be room for the development of a systematic methodology. 

Pissarra PD, Nielsen J (1997) Thermodynamics of metabolic pathways for penicillin production analysis of thermodynamic feasibility and free-energy changes during fed-batch cultivation.Biotechnology Prog 13 156-165... 

This chapter contains a general discussion of the thermodynamics of metabolic processes, with the (unevaluated) data Itself being presented In the course of the discussion. The emphasis is almost entirely upon Gibbs energy changes measured under physiological or near physiological conditions. There are 143 references to the primary literature. 

Atkinson, D. E. (1977) Cellular Energy Metabolism and its Regulation, Academic Press, New York Jones, M. N. (ed.) (1979) Biochemical Thermodynamics, Elsevier, Amsterdam... 

Sun emblem of Louis XTV on a gate at Versailles. The sun is the prime souree of energy for life, and thermodynamics is the gateway to understanding metabolism. (Giraudou/Art Research, New York)... 

In the following section, the calculation of the VolSurf parameters from GRID interaction energies will be explained and the physico-chemical relevance of these novel descriptors demonstrated by correlation with measured absorption/ distribution/metabolism/elimination (ADME) properties. The applications will be shown by correlating 3D molecular structures with Caco-2 cell permeabilities, thermodynamic solubilities and metabolic stabilities. Special emphasis will be placed on interpretation of the models by multivariate statistics, because a rational design to improve molecular properties is critically dependent on an understanding of how molecular features influence physico-chemical and ADME properties. 

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