摘要:

AbstractThe proton occupies a special position as a promoter and mediator in chemical reactions occurring in solution. Many reactions in organic chemistry are catalysed by acids or bases; likewise, most enzymes contain active groups which promote acid‐base catalysis. To understand the reaction mechanisms involved, it is necessary to identify the elementary steps as well as their course in time. Systematic investigation of these elementary steps as well as their course in time. Systematic investigation of these elementary steps has become possible only with the development of new methods for studying very fast reactions. The present paper reviews the information obtained in this type of investigation. The result is a relatively complete picture of the elementary proton transfer mechanisms and a comprehensive description of the modes and laws of acid‐base and enzymatic cataly

ISSN:0570-0833    

DOI:10.1002/anie.196400011

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractKetones react with sulfur and NH3or amines at room temperature to produce Δ3‐thiazolines, 5‐alkylidene‐Δ3‐thiazolines, Δ3‐imidazoline‐5‐thiones, hexathiacycloheptane derivatives, α,α′‐dioxodisulfides, bis‐(1‐aralk‐1‐yl) disulfides, or thiocarboxamides, depending on the coreactant and on the reaction conditions. It was recognized that the formation of all of these numerous types of compounds can be explained basically by primary thiolations and geminal dithiolations, which in conjunction with their reverse reaction (desulfurization) and the assumption of a thioreductone equilibrium permit a new interpretation of the course of the Willgerodt‐Kindle

ISSN:0570-0833    

DOI:10.1002/anie.196400191

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractLysozymes are widely distributed enzymes. They split the chemical skeleton of bacterial cell walls by hydrolysing the β (1 → 4) linkages between N‐acetylmuramic acid and N‐acetylglucosamine. the amino acid sequence of lysozyme from hen's egg‐white is known (129 amino acid residues). Lysozymes of different origins frequently differ in their primary structures although they exhibit qualitatively the same biological activity. The results obtained from investigations with lysozymes allow conclusions to be drawn regarding the chemical structure of the “backbone” of bacteria

ISSN:0570-0833    

DOI:10.1002/anie.196400281

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractA review of the various theories of potential formation on the glass‐electrode is followed by a discussion of the deviations from the ideal hydrogen (H) electrode function in the acidic and alkaline ranges from the viewpoint of the phase‐boundary‐potential theory. The effect of the composition and solubility of the glasses on the electromotive behavior is interpreted as a “medium effect” in the

ISSN:0570-0833    

DOI:10.1002/anie.196400361

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractThe reactions of the oxides SiO2, MoO3, and WO3with steam at temperatures between 400 and 700 °C and pressures of 5 to 500 atm were studied by means of the transfer method. The results were evaluated by a new method. In the system Sio2/H2O the formation of gaseous Si(OH)4, Si2O(OH)6, and [SiO2(OH)2]xwas found to occur in three different water‐density ranges. In the systems MoO3/H2O and WO3/H2O the gaseous compounds MoO2(OH)2and WO2(OH)2, which were already known, exist up to densities of approximately 0.05g/cm3. At higher densities, at which the supercritical phase begins to show the properties of a liquid to an ever increasing extent, isopolymolybdic or isopolytungstic acids appe

ISSN:0570-0833    

DOI:10.1002/anie.196400471

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractIn oxidative phosphorylation, the energy from the combustion of substrate hydrogen can be reversibly transformed into phosphate‐bond energy. This is the reason that oxidation‐reduction reactions in the respiratory chain can take place against the redox potential gradient if energy is supplied. The latter can come from ATP or directly from energy‐rich intermediates arising in the course of oxidative phosphorylation. – At the center of the present considerations is the postulate that there is an equilibrium prevailing in the respiratory chain that results from the reversibility of the reactions. At the same time this postulate provides a unifying approach to various phenomena related to the process of oxidative phosphorylation. Such an equilibrium may involve several components of the respiratory chain. Respiration thus corresponds to a dynamic equilibrium in the respiratory chain which deviates increasingly from the static equilibrium the greater the rate of respiration. Consequently, respiration can be considered as being regulated by the phosphorylation potential. – The stationary redox state of the components of the respiratory chain can be viewed as a simulataneous function of the phosphorylation potential and of the redox potential that effects both ends of the respiratory chain. The latter reacts to either extreme, i.e. to minimum or maximum differences in the redox potential, by forming characteristic patterns of the state of reduction of its components. Differences in redox potential amounting to as much as 280 mV can be over‐come by the phosphorylation potential for a single phosphorylative step. – The conditions for an equilibrium in the respiratory chain are also fulfilled from a kinetic viewpoint as the rates of the reverse reactions involving either electron or proton transfer are of the same order of magnitude as those of the forw

ISSN:0570-0833    

DOI:10.1002/anie.196400541

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196400611

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196400621

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196400632

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196400642

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY