Quantum biology is the application of the theory of open quantum systems to aspects of biology where classical physics fails to give an accurate de- scription. The most well-established area in quantum biology is the study of photosynthesis.
There exists a body of evidence that the primary photosynthetic processes of energy and charge transfer exhibit quantum mechanical properties essential for function and that cannot be described by classical physics. Open quantum systems models of excitation energy transfer and electron transfer in primary photosynthesis have elucidated many aspects of the relation between struc- ture and function in the photosynthetic complex, as well as contributed to an understanding of the role of the environment in quantum transport processes.
After an introduction to quantum biology, an overview of open quantum systems approaches to transfer processes in primary photosynthesis is given. Our results on decoherence-assisted transport in the context of photosyn- thetic excitation energy transfer, as well as our proposal of the direct role of spin in a protection mechanism during photosynthetic charge transfer, are presented. Finally, thoughts around an outlook for quantum biology are given.
Noise in dynamical systems is usually considered a nuisance. But in certain nonlinear systems, including electronic circuits and biological sensory apparatus, the presence of noise can in fact enhance the detection of weak signals. This phenomenon, called stochastic resonance, may find useful application in physical, technological and biomedical contexts.
Quantum mechanics provides the most accurate microscopic description of the world around us, yet the interface between quantum mechanics and biology is only now being explored. This book uses a combination of experiment and theory to examine areas of biology believed to be strongly influenced by manifestly quantum phenomena. Covering subjects ranging from coherent energy transfer in photosynthetic light harvesting to spin coherence in the avian compass and the problem of molecular recognition in olfaction, the book is ideal for advanced undergraduate and graduate students in physics, biology and chemistry seeking to understand the applications of quantum mechanics to biology.
This text provides a uniform and consistent approach to diversified problems encountered in the study of dynamical processes in condensed phase molecular systems. Given the broad interdisciplinary aspect of this subject, the book focuses on three themes: coverage of needed background material, in-depth introduction of methodologies, and analysis of several key applications. The uniform approach and common language used in all discussions help to develop general understanding and insight on condensed phases chemical dynamics. The applications discussed are among the most fundamental processes that underlie physical, chemical and biological phenomena in complex systems. The first part of the book starts with a general review of basic mathematical and physical methods (Chapter 1) and a few introductory chapters on quantum dynamics (Chapter 2), interaction of radiation and matter (Chapter 3) and basic properties of solids (chapter 4) and liquids (Chapter 5). In the second part the text embarks on a broad coverage of the main methodological approaches. The central role of classical and quantum time correlation functions is emphasized in Chapter 6. The presentation of dynamical phenomena in complex systems as stochastic processes is discussed in Chapters 7 and 8. The basic theory of quantum relaxation phenomena is developed in Chapter 9, and carried on in Chapter 10 which introduces the density operator, its quantum evolution in Liouville space, and the concept of reduced equation of motions. The methodological part concludes with a discussion of linear response theory in Chapter 11, and of the spin-boson model in chapter 12. The third part of the book applies the methodologies introduced earlier to several fundamental processes that underlie much of the dynamical behaviour of condensed phase molecular systems. Vibrational relaxation and vibrational energy transfer (Chapter 13), Barrier crossing and diffusion controlled reactions (Chapter 14), solvation dynamics (Chapter 15), electron transfer in bulk solvents (Chapter 16) and at electrodes/electrolyte and metal/molecule/metal junctions (Chapter 17), and several processes pertaining to molecular spectroscopy in condensed phases (Chapter 18) are the main subjects discussed in this part.
Anoxygenic Photosynthetic Bacteria is a comprehensive volume describing all aspects of non-oxygen-evolving photosynthetic bacteria. The 62 chapters are organized into themes of: Taxonomy, physiology and ecology; Molecular structure of pigments and cofactors; Membrane and cell wall structure: Antenna structure and function; Reaction center structure and electron/proton pathways; Cyclic electron transfer; Metabolic processes; Genetics; Regulation of gene expression, and applications. The chapters have all been written by leading experts and present in detail the current understanding of these versatile microorganisms.
The book is intended for use by advanced undergraduate and graduate students and senior researchers in the areas of microbiology, genetics, biochemistry, biophysics and biotechnology.
Programmed cell death is a common pattern of growth and development in both animals and plants. However, programmed cell death and related processes are not as generally recognized as central to plant growth. This is changing fast and is becoming more of a focus of intensive research. This edited work will bring under one cover recent reviews of programmed cell death, apoptosis and senescence.
As knowledge regarding the formation of organic compounds from carbon dioxide and other inorganic materials in green plants accumulates, it becomes increasingly apparent that it is difficult to distinguish which transformations of carbon compounds should be classified as part of the pathway of carbon in photosynthesis and which reactions should be considered as other metabolic processes of the plant. All reactions of a photoautotrophic plant rely ultimately on the energy stored by the photosynthetic process. Therefore, any definition of carbon reduction during photosynthesis based on requirement of energy or equivalents of reducing agents should specify the requirement precisely. Even so, it is questionable whether such a definition can distinguish between carbon reduction reactions of photosynthesis and other metabolic transformations of carbon compounds. It is now believed that energy-carrying compounds such as adenosine triphosphate and reducing agents such as reduced triphosphopyridine nucleotide which are formed during respiratory processes may also be formed directly from products close to the primary photochemical reactions of photosynthesis. Transformations of carbon compounds which require such substances and which take place in the dark may also occur at a greatly accelerated rate during photosynthesis. Furthermore, most, if not all, of the reactions of carbon reduction in photosynthesis are known to occur, although at a diminished rate, in the dark long after the immediate reducing and energy-carrying agents formed from the photochemical reaction have decayed.