Chemical differences between living and

The space-time theory of Vernadsky is required to prove the thesis of the cardinal difference between living and inert matter and, hence, the indeducibility of the biological processes from the separate set of physical-chemical laws. The piroblem of the cardinal difference between living and inert matter is, in its turn, connected with all... 

All three theories compose an unified theoretical system. This is indicated, for example, by the fact that there are concepts which appear in all three parts of the system. One of the illustrative examples is the concept of space-time dissymmetry, which appears in all parts of Vernadsky s theoretical heritage. The spM -time theory - the main concept of which is dissymmetry - is required to prove the thesis of the cardinal difference between living and inert matter and, hence, the indeducibility of the biological processes from a separate set of physical-chemical laws. The problem of the cardinal differeiKe between living and inert matter is a very important point, because it is connected with all the important claims of Vernadsky s theoretical system (i) the first, second and third biogeochemical principles, (ii) the Redi principle, (iii) the concept of the evolution of the biosphere. 

This is an essential topic for biochemists and biochemical engineers. Biochemical reactions involve both cellular and enzymatic processes, and the principal differences between biochemical and chemical reactions lie in the nature of the living systems. Biochemists and biochemical engineers can stabilize most organic substances in processes involving microorganisms. 

The alternative method is continuous-flow , in which the reactants flow through the detection coil during data acquisition. Continuous-flow NMR techniques have been used for the direct observation of short-lived species in chemical reactions [4—6]. The main difference between stopped- and continuous-flow NMR is that in the latter the sample remains inside the detection coil only for a short time period, termed the residence time, x [7], which is determined by the volume of the detection cell and the flow rate. The residence time alters the effective relaxation times according to the relationship in Eq. (2.5.1) ... 

The difference between the two reactions of Scheme 2.9 may also be considered in terms of the complete electron transfer in both cases. If the a-nitrostilbene anion-radical and metallocomplex cation-radical are formed as short-lived intermediates, then the dimerization of the former becomes doubtful. The dimerization under electrochemical conditions may be a result of increased concentration of reactive anion-radicals near the electrode. This concentration is simply much higher in the electrochemical reaction because all of the stuff is being formed at the electrode, and therefore, there is more dimerization. Such a difference between electrode and chemical reactions should be kept in mind. In special experiments, only 2% of the anion-radical of a-nitrostilbene were prepared after interruption of controlled-potential electrolysis at a platinum gauze electrode. The kept potential was just past the cathodic peak. The electrolysis was performed in the well-stirred solution of trani -a-nitrostilbene in AN. Both processes developed in this case, namely, trans-to-cis conversion and dimerization (Kraiya et al. 2004). The partial electrolysis of a-nitrostilbene resulted in redox-catalyzed equilibration of the neutral isomers. 

With few exceptions, enantiomers cannot be separated through physical means. When in racemic mixtures, they have the same physical properties. Enantiomers have similar cliemi cal properties as well. The only chemical difference between a pair of enantiomers occurs in reactions with other chiral compounds. Thus resolution of a racemic mixture typically takes place through a reaction with another optically active reagent. Since living organisms usually produce only one of two possible enantiomers, many optically active reagents can be obtained from natural sources. For instance muscle tissue and (S)-<-)-2-methyl-l-butanol, from yeast fermentation. 

Selection pressures on cuticular chemical resemblance between hosts and parasites are expected to be even weaker when parasite sexuals are taken into account. Indeed, sexuals are cared for by enslaved host workers and live inside the natal colonies until the mating flight. As expected, in Chalepoxenus muellerianus (a slave making ant which enslaves multiple hosts of the related Temnothorax species), the complex hydrocarbon profiles of sexuals depend on the host-rearing species, with a bias towards the host species used by each parasite population, but with differences among the chemical signatures of parasite sexuals and workers of the host species (Beibl et al., 2007). It is obvious, from the example... 

Most of the studies of particulate matter in the oceans concern themselves with suspensions recovered on filters and do not take into account the difference between detritus and living matter. Therefore, it is very difficult to estimate the respective impact of biological and chemical processes. Although there are many extensive studies of particles in the euphotic layer (Sutcliffe et al., 1970 Zeitschel, 1970 Flemer and Biggs, 1971 Wada and Hat-tori, 1976), only by examination of deep-sea suspensions can we understand the geochemistry of marine organic detritus. 

The chemical interest of these trace amount proteins stems from the fact that they can be used as catalysts or enzyme analogs for almost any chemical reaction (Tramontano et al., 1986 Pollack et al., 1986 Lemer et al., 1991). The fundamental difference between antibodies and enzymes does not relate so much to the protein structures as to the structure and lifetime of the substrates. Antibodies selectively bind molecules in their ground state, whereas enzymes selectively produce and then bind more strongly to short-lived transition states. Antibody-antigen complexes tend toward precipitation, whereas enzyme-transition state complexes react to enzyme-product complexes, which immediately dissociate. In both cases, however, the same noncovalent bonds are used. 

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