Info Haz
Structure Formation of Biomacromolecules In the preceding sections, problems relating to the information content of biomacromolecules were discussed, the idea of random coil formation by molecular chains as a state of maximum entropy was introduced, as well as the role of water in the entropy balance of macromolecular systems, and the broad spectrum of intermolecular interactions. A knowledge of these aspects is an important pre-requisite to understanding the dynamic structure of proteins and...
Info Vlq
The Electrostatic Structure of the Membrane After explaining some structural and mechanical properties of biological membranes in Sections 2.5.2 and 2.5.3, and after having discussed ionic properties near fixed charges, we will now introduce the membrane as an electrical structure. This seems to be a crucial point for many biophysical considerations, and it will pervade this whole book. Electrical properties of the biological membrane will be mentioned in the context of many topics. Whereas we...
Coordinative Bonds MetalloOrganic Complexes
The stability of a series of biologically important molecules is mediated by polyvalent metals and transition elements. This stability cannot be explained either by single covalent bonds, or by ionic bonds. For these types of bonds, which occur mainly in inorganic chemistry, the terms coordinative bonds or complex bonds have been introduced. These complexes, which may also be charge-carrying ions, consist of a central atom which is surrounded by ligands, i.e. molecular complexes, in...
List of Fundamental Constants and Symbols
The numbers in parentheses indicate equations in the text, where the symbols are explained or defined. A Arrhenius-coefficient Eq. 2.3.17 a chemical activity Eq. 3.1.34 B magnetic flux density Eq. 4.4.1 b electrophoretic mobility Eq. 2.5.13 C electric capacity Eq. 3.5.6 C complex electric capacitance Eq. 3.5.11 Q clearance-constant Eq. 5.2.28 Cy isochoric heat capacity Eq. 2.4.25 c0 speed of light in vacuum 2.998 108 m s-1 D diffusion coefficient Eq. 3.3.6 standard redox potential Eq. 2.2.1 E...
Photosynthesis as Process of Energy Transfer and Energy Transformation
Molecular processes of energy transformation take place in many metabolic systems. Of special interest, however, are the primary reactions in which the quantum energy of sunlight is transformed into the energy of chemical bonds. This is the case in photosynthesis, as well as in photoreception. Photosynthesis is the first step of energy gain in the biosphere. Photoreception on the other hand, is a process of signal transduction. About 0.05 of the total 1022 kj energy which reaches the earth...
Info Hua
Fig. 2.34. The average number of charges z of glycine plotted against the pH in the solution. pKi 2.35, pK2 9.78 Glycine is a cation at extremely low pH, and in contrast an anion at extremely high pH. In the pH region in between, both groups of this molecule are dissociated, demonstrating the zwitterionic character of this molecule. In this case it has a considerable dipole moment and a maximal number of charges but on average it is electro neutral. This curve allows us to determine two...
Thermodynamic Probability and Entropy
In 1854, Rudolf J. E. Clausius introduced the entropy S as a parameter of phenomenological thermodynamics, and defined it as the heat, added to a system in a reversible way in relation to the temperature see Eq. 3.1.10 . Later, in 1894, Ludwig Boltzmann used this parameter in the framework of statistical thermodynamics. In this context, entropy and the second principle of thermodynamics become more imaginable. Entropy appears as a kind of measure of disorder, or as a degree of random...
Preface
Was war also das Leben Es war W rme, das W rmeprodukt formerhaltender Bestandlosigkeit, ein Fieber der Materie, von welchem der Proze unaufh rlicher Zersetzung und Wiederherstellung unhaltbar verwickelt, unhaltbar kunstreich aufgebauter Eiwei molekel begleitet war. Es war das Sein des eigentlich Nicht-sein-K nnenden, des nur in diesem verschr nkten und fiebrigen Proze von Zerfall und Erneuerung mit s -schmerzlich-genauer Not auf dem Punkte des Seins Balancierenden. Es war nicht materiell und es...
Nature and Subject of Biophysics
The subjects of biophysics are the physical principles underlying all processes of living systems. This also includes the explanation of interactions of various physical influences on physiological functions, which is a special sub-area, called environmental biophysics. Biophysics is an interdisciplinary science somewhere between biology and physics, as may be concluded from its name, and is furthermore connected with other disciplines, such as mathematics, physical chemistry, and biochemistry....
Energetics and Dynamics of Biological Systems
The functions of biological systems are based on a highly organized molecular structure. So, in Section 2, we considered firstly the physical principles ruling molecular and supramolecular structures. This was done using approaches of quantum mechanics and statistical thermodynamics. Now we will come to various functions of cells, tissues, and organs. For this, of course, molecular considerations form an important fundament, but at the same time, we enter the field of so-called continuum...
Info Ruc
Fig. 2.30. The distance function j r of the van der Waals energy of interaction between particles of various shape. Parameters after Israe-lachvili 1974 - The interaction force between two particles results from the sum of the particular forces, each one decreasing with increasing distances in different ways. - In contrast to generally attractive van der Waals forces, electrostatic interactions can also become repulsive. - The intensity of electrostatic interactions, in contrast to van der...
T11111
Fig. 2.11. An example for an Arrhenius-plot the logarithm of the activity of isolated ATPase A is plotted versus the reciprocal value of the temperature in a region between 15 and 40 C. Parameters from Blank and Soo 1992 be expected which is much more complicated than that expressed by the Arrhenius equation Eq. 2.3.17 . Surprisingly, however, even in these cases functions will still be obtained which can be described by straight lines in the Arrhenius plot. This is caused by the fact that in...
Covalent Bonds Molecular Orbitals
The calculation of molecular orbitals provides the basis for the theoretical interpretation of atomic interactions. A mutual approach of atoms is accompanied by an overlapping of their electromagnetic fields and, consequently, by a change in the wave function of their electrons. The energy levels of the wave functions, modified in such a way, can sink lower than the sum of the levels of energy of the undisturbed atoms. In this case the connection of the two atoms becomes a stable chemical bond....