摘要:

AbstractThe main energy source for all endergonic processes occurring in living organisms is the phosphate bond energy of nucleoside triphosphates, especially adenosine triphosphate (ATP). In aerobic organisms, as for instance in mammals, more than 90% of ATP is formed during the process called oxidative phosphorylation. In this process, similar to that of muscle contraction and nerve excitation, nature works with vectorial processes taking place at a membrane separating distinct spaces from each other. The present article deals with the operation of a set of water‐insoluble membrane proteins and enzymes vectorially transporting electrons, protons and other ions, which finally leads to the formation of ATP. This machinery transforming substrate oxidation energy into chemical energy in the form of the phosphoric anhydride bond of ATP operates with a very high efficiency.The structure and function of the machinery of mitochondrial oxidative phosphorylation are described. It consists of the electron transfer chain, the ATP‐synthetase, the adenine nucleotide translocase and the phosphate carrier. The electron transfer chain can be resolved into multiprotein complexes—at three of them energy conversion takes place—and into the electron carriers ubiquinone and cytochrome c. The substrate oxidation energy is converted into the chemical energy of ATP with an electrochemical proton gradient as intermediary form. The energetic aspects of the processes are analyzed by linear irreversible thermodynamics. Great success has been gained during the past few years on the structural characterization of the participating proteins. The function of the various systems is partially elucidated on the molecular level; this concerns especially the mechanism of proton and adenine nucleotide translocation, as well as ATP fo

ISSN:0570-0833    

DOI:10.1002/anie.198006593

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractA fascinating feature inherent to aqueous surfactant solutions is the phenomenon of self‐organization: above a certain critical concentration (the critical micelle concentration, CMC) detergent molecules associate spontaneously to build up structural entities of colloidal dimensions called micelles. The architecture of these agglomerates is such that the interior contains the hydrophobic alkyl chain of the amphiphile while the hydrophilic head groups are located at the surface and are in contact with bulk water. In the case of ionic micelles the interface is charged giving rise to an electrical double layer and a potential difference of up to several hundred millivolts between the micellar pseudophase and water. Thus micellar systems are microheterogeneous in character: the electrostatic potential and polarity prevailing in the interior of the aggregate differ from those of the bulk aqueous phase. A particularly attractive aspect of photochemical studies in micellar systems is the possibility of organizing the reactants at a molecular level: by comparison of the data in micelles with similar data in homogeneous solution one can learn about the molecular details of a given reaction and establish which conditions favor one pathway or another. In simple surfactant systems differences in rate and efficiency of a reaction will often be controlled by local electrostatic potentials and the compartmentalization of the reagents within the surfactant aggregates. Through the latter effect the statistics of probe distribution over the micelles becomes important in controlling fast photochemical events. Functional micelles are distinguished by the fact that the surfactant molecule contains a group which itself participates in the photoprocess. These units are unique in that self‐assembly often introduces striking cooperative effe

ISSN:0570-0833    

DOI:10.1002/anie.198006751

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractLiquid structure is described by the pair‐correlation function. If the liquied particles are molecules then the respective correlation function depends on distance and several angular variables; hence, for the sake of simplicity a symmetry‐adapted representation must be used. The most important structural parameters of this molecular pair‐correlation function can be determined approximately by a combination of several scattering experiments, such as neutron (employing different isotopes), X‐ray and electron diffraction. Light scattering, dielectric, and nuclear magnetic relaxation experiments provide further, albeit less direct, access to such determinations. Some results obtained by measurements on chloroform are reported. Theoretical computations of these structural parameters are also di

ISSN:0570-0833    

DOI:10.1002/anie.198006971

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198007081

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198007091

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198007101

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198007121

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198007131

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198007141

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198007151

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY