XIX Thermodynamics and Kinetics in Biochemical Reactions (1,7,38,64)

2015 ◽  
pp. 288-323
2014 ◽  
Vol 36 (3) ◽  

Robert A. Alberty, professor emeritus in the Department of Chemistry and former dean of MIT’s School of Science—whose seminal contributions to the thermodynamics and kinetics of biochemical reactions are still at the forefront of chemistry—passed away on 18 January 2014, at the age of 92.


Author(s):  
R. J. Lauf

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.


Author(s):  
A.V. Shitikova ◽  
◽  
A.A. Abiala

The results of studies on the role of growth biostimulants in the exogenous regulation of potato productivity on sod-podzolic soils of the Moscow region are presented.Studies have established the specificity of the action of phytohormones.The stimulating effect of the drugs manifested itself in the intensification of metabolic processes, changing the direction of biochemical reactions, which led to an increase in productivity.


2004 ◽  
Vol 29 (2) ◽  
pp. 1-9
Author(s):  
Mustapha Boulghallat ◽  
Ahmed Jouaiti ◽  
Norbert Gérard

2000 ◽  
Vol 42 (3-4) ◽  
pp. 265-272 ◽  
Author(s):  
T. Inoue ◽  
Y. Nakamura ◽  
Y. Adachi

A dynamic model, which predicts non-steady variations in the sediment oxygen demand (SOD) and phosphate release rate, has been designed. This theoretical model consists of three diffusion equations with biochemical reactions for dissolved oxygen (DO), phosphate and ferrous iron. According to this model, step changes in the DO concentration and flow velocity produce drastic changes in the SOD and phosphate release rate within 10 minutes. The vigorous response of the SOD and phosphate release rate is caused by the difference in the time scale of diffusion in the water boundary layer and that of the biochemical reactions in the sediment. Secondly, a negative phosphate transfer from water to sediment can even occur under aerobic conditions. This is caused by the decrease in phosphate concentration in the aerobic layer due to adsorption.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Antonio Sabatini ◽  
Marco Borsari ◽  
Gerard P. Moss ◽  
Stefano Iotti

AbstractAccording to the 1994 IUBMB-IUPAC Joint Commission on Biochemical Nomenclature (JCBN) on chemical and biochemical reactions, two categories of thermodynamics, based on different concepts and different formalisms, are established: (i) chemical thermodynamics, which employ conventional thermodynamic potentials to deal with chemical reactions [1], [2], [3]; and (ii) biochemical thermodynamics, which employ transformed thermodynamic quantities to deal with biochemical reactions based on the formalism proposed by Alberty [4], [5], [6], [7]. We showed that the two worlds of chemical and biochemical thermodynamics, which so far have been treated separately, can be reunified within the same thermodynamic framework. The thermodynamics of chemical reactions, in which all species are explicitly considered with their atoms and charge balanced, are compared with the transformed thermodynamics generally used to treat biochemical reactions where atoms and charges are not balanced. The transformed thermodynamic quantities suggested by Alberty are obtained by a mathematical transformation of the usual thermodynamic quantities. The present analysis demonstrates that the transformed values for ΔrG′0 and ΔrH′0 can be obtained directly, without performing any transformation, by simply writing the chemical reactions with all the pseudoisomers explicitly included and the elements and charges balanced. The appropriate procedures for computing the stoichiometric coefficients for the pseudoisomers are fully explained by means of an example calculation for the biochemical ATP hydrolysis reaction. It is concluded that the analysis reunifies the “two separate worlds” of conventional thermodynamics and transformed thermodynamics.


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