Bioenergetics

ISBN-13: 9783034898607 / Angielski / Miękka / 2011 / 542 str.

Peter Graber; Giulio Milazzo

Opis

Bioenergetics, the topic of volume 5 of this Series, is concerned with the energetics, the kinetics, and the mechanisms of energy conversion in biological systems. This phenomenon can be investigated on diffe- rent levels of complexity. On a global level the role of biological pro- cesses for the steady state of our enviroment is considered. At the physiological level, the relation between energy input and the physiolo- gical state of an organism is of interest, while at the cellular level the biochemical pathways for degradation and synthesis of all relevant substrates is investigated. At present the majority of bioenergetic stu- dies pertain to the molecular level. The processes in a cell are cataly- zed by a large number of proteins called enzymes. The enzymes in- volved in energy transduction can be considered as molecular ma- chines which transform energy from one form into another, or transfer energy from one process to another. Living systems operate far from equilibrium and are open in the ther- modynamic sense, i. e. they exchange energy and matter with the sur- roundings. Chapter 1 presents the principles of non equilibrium thermo- dynamics applied to biological systems. About 0. 05% of the energy from the sunlight which reaches the surface of the earth is used by plants and algae as well as some bacteria to synthesize organic com- pounds, and thus supplies all organisms with the energy necessary for life.

Spis treści

1. Nonequilibrium thermodynamics applied to energy conversion in biological systems.- • Introduction.- • Elements of nonequilibrium thermodynamics.- • Steady states.- • Mechanisms of coupling between processes.- • Phenomenological description of processes and systems.- • Control and regulation of processes.- 2. Global bioenergetics.- • Introduction.- • Thermodynamic principles.- • Thermodynamic efficiencies and global bioenergetics.- • The current steady state: Global cycles of matter associated with global bioenergetics.- • Approach to the current steady state: Evolution of free-enthalpy transducing biosystems.- 3. Vectorial bioenergetics.- • Bioenergetics in a homogeneous compartment.- • Cellular compartmentation and bioenergetics.- • Proton bioenergetics.- • Transport phenomena.- • Sodium bioenergetics.- 4. Energetics of aerobic and anaerobic bacteria.- • Introduction.- • Principles of biological energy transformations.- • Energy-generating processes.- • Energy-requiring processes.- 5. Chloroplasts.- • Introduction.- • Light-driven electron transport and proton translocation.- • Carbon metabolism.- • Other metabolic pathways.- • Transport across the envelope.- • Photoregulation of chloroplast function.- 6. The mammalian mitochondrial respiratory chain.- • Introduction.- • Principles of electron transfer-linked proton translocation.- • NADH: ubiquinone oxidoreductase (complex I).- • Succinate: ubiquinone oxidoreductase (complex II).- • Ubihydroquinone: cytochrome c oxidoreductase (complex III).- • The diffusible redox carriers ubiquinone and cytochrome c.- • Energy balance of electron transfer reactions.- • Carrier proteins involved in energy transduction.- • Interaction of electron transfer chain, ATP synthase, adenine nucleotide carrier, and phosphate carrier, resulting in the coupling of oxidative phosphorylation.- 7. Photosystem II and water oxidation in cyanobacteria, algae and higher plants.- • Introduction.- • Overall organisation of water cleavage in Photosystem II.- • Light absorption and transformation into electrochemical free energy in Photosystem II.- • Water oxidation.- • Plastoquinone reduction.- 8. The photosystem I reaction center in oxygenic photosynthesis.- • Introduction.- • Energy transfer in PS-I.- • Electron transfer in PS-I.- • Polypeptides of the PS-I reaction center.- • Structure of the PS-I reaction center.- • Comparison with green sulfur bacteria and heliobacteria.- 9. The cytochrome b6f/bcl-complexes.- • Introduction.- • Occurrence.- • Components and structure.- • Function.- • Regulation.- 10. Cytochrome c oxidase.- • Introduction.- • Structure.- • Spectroscopy.- • Ligand binding reactions.- • Electron transfer reactions.- • Proton transfer reactions.- • Electrochemistry of the metal centres.- 11. Bacteriorhodopsin.- • Introduction.- • The bacterium.- • Bioenergetics of H. salinarium.- • The bacteriorhodopsin in purple membrane.- • The photocycle.- • Halorhodopsin.- 12. Structure, function and regulation of the H+-ATPases from chloroplasts.- • Introduction.- • Structure of H+-ATPases.- • The catalytic reaction of H-ATPases.- • The regulation of CF0F1.