Muscles as Molecular and Metabolic Machines


Book Description

First published in 1994, this book explores the paradigm of muscles as molecular and metabolic machines in which all structures and functions are exquisitely integrated and matched to each other. The analysis begins with a standard reductionist approach-reviewing the integrated machine parts. The key working components of the complete muscle machine are proteins (soluble, organelle, or membrane localized), and a conservative count indicates that today more than 100 such machine parts are known, essentially all occurring as cell specific isoforms. Random assortment of these machine parts or protein isoforms could generate an astronomical number of "muscle machines" and an equally enormous number of muscle fiber types. The question is, why aren't such large numbers ever seen? To attack this problem, the reductionist approach is complemented with an integrationist/adaptational one. Evidence is presented that the more highly specialized the muscle type, the further one moves from the above extreme; in the most highly specialized muscles, typically only one fiber type is found. It is argued that instead of random assortment of isoforms or machine parts, only specific and often unique combinations can work in appropriate fashion. A few established examples of this fundamental principle are reviewed, but emphasis is placed on the fact that we know dreadfully little about why this is so and what kinds of further studies are needed. The issue of why the very large numbers of fiber types theoretically possible are never even approximately realized has never before been addressed. Indeed, it is rarely recognized. Muscles as Molecular and Metabolic Machines is the first work of its kind on the subject.




The Role of Protein and Amino Acids in Sustaining and Enhancing Performance


Book Description

It is a commonly held belief that athletes, particularly body builders, have greater requirements for dietary protein than sedentary individuals. However, the evidence in support of this contention is controversial. This book is the latest in a series of publications designed to inform both civilian and military scientists and personnel about issues related to nutrition and military service. Among the many other stressors they experience, soldiers face unique nutritional demands during combat. Of particular concern is the role that dietary protein might play in controlling muscle mass and strength, response to injury and infection, and cognitive performance. The first part of the book contains the committee's summary of the workshop, responses to the Army's questions, conclusions, and recommendations. The remainder of the book contains papers contributed by speakers at the workshop on such topics as, the effects of aging and hormones on regulation of muscle mass and function, alterations in protein metabolism due to the stress of injury or infection, the role of individual amino acids, the components of proteins, as neurotransmitters, hormones, and modulators of various physiological processes, and the efficacy and safety considerations associated with dietary supplements aimed at enhancing performance.







Biochemical Adaptation


Book Description

Suitable for graduates and undergraduates in environmental biology, comparative physiology, and marine biology, this text lays out the principles of mechanistic comparative physiology in an ecological and evolutionary context. This text lays out the principles of mechanistic comparative physiology in an ecological and evolutionary context. The subject of evolutionary physiology has been advancing considerably and this book will bring readers up to date on a number of new techniques, ideas and data. Topics include NMR spectroscopy and molecular biology, evolution and adaptation, phylogenetically-based analytical techniques and more.







Principles of Human Locomotion


Book Description

This book addresses how the general principles of biology influence the human capacity for locomotion, and, conversely, how understanding the nature of muscular activity might provide insights into the basic nature of living beings. Through a series of essays, the book relates the evolutionary basis of animal locomotion to recognizing the determinants of exercise capacity. While raising more questions than providing answers, the discussions will assume that without knowing the correct questions to ask, the answers will not be forthcoming. At the root of this book lies the central query: what is it that separates the principles governing the function of living beings from those that dictate the inanimate world? The discussions here address this issue from the expectation that clues to the answer can be obtained through understanding adaptations to the stresses imposed by physical exercise. As such, the book provides thought-provoking analyses of the biological basis of locomotion that will stimulate future efforts to understand these phenomena.




Metabolism of Anabolic-Androgenic Steroids


Book Description

This book presents an authoritative review of the research regarding the influences of anabolic-androgenic steroids on metabolism. The book provides a concise description of the biochemistry of these steroids using simple terms and includes methods of separation and their clinical applications. The first section of the book examines the general structure, nomenclature, and classification of anabolic-androgenic steroids. Subsequent chapters explore concepts basic to understanding the pathways of their metabolism in both target and non-target tissues, including the interactions of steroids with receptors and the effects of steroids on the cellular metabolism of skeletal muscle. The changes and molecular base of modifications in metabolism during exercise involving anabolic-androgenic steroids are also described. Finally, a comprehensive review of methods for scanning and identifying anabolic-androgenic steroids in biological fluids is presented, as well as a discussion regarding the applicability and limitations of these techniques. The book provides valuable reference information for all scientists and clinicians engaged in sports medicine, exercise biochemistry, and endocrinology.




Technological and Medical Implications of Metabolic Control Analysis


Book Description

Two decades have passed since the mechanisms of protein synthesis became well enough understood to permit the genetic modification oforganisms. An impressive amount of new knowledge has emerged from the new technology, but much ofthe promise of20years ago has notyet been fulfilled. In biotechnology, efforts to increase the yields of commercially valuable metabolites have been less successful than ex pected, and when they have succeeded it has often been as much from selective breeding as from new methods. The cell is more complicated than what is presented in the classical teaching of biochemistry, it contains more structure than was dreamed of 20 years ago, and the behaviour ofany systemofenzymes is more elaborate than can be explained in terms ofa single supposedly rate-limiting enzyme. Even if classical enzymology and meta bolism may have seemed rather unfashionable during the rise ofmolecular biology, they remain central to any modification ofthe metabolic behaviour oforganisms. As such modification is essential in much ofbiotechnology and drug development, bio technologists can only ignore these topics at their peril.




Physical Activity and Health


Book Description

The human body is designed for activity. For most of our history, physical activity was required for survival, but technological advances have eliminated much of the need for hard physical labor. As our activity levels have dropped, it has become clear that a physically inactive lifestyle can lead to a host of health problems. Physical Activity and Health, Second Edition, provides a comprehensive treatment of the research on the benefits of a physically active lifestyle in comparison with the harmful consequences of physical inactivity. Written by leading scientists from the United States, Canada, Europe, and Australia, Physical Activity and Health, Second Edition, brings together the results of the most important studies on the relationship between physical activity, sedentarism, and various health outcomes. The second edition has been fully updated based on the latest advances in this rapidly changing field and expanded to include the following new content: • A chapter on the physiology of inactivity and the effects of sedentary behavior even in people who engage in appropriate amounts of physical activity, which is an area of growing interest • More extensive coverage of physical activity, aging, and the brain, including a new chapter on the relationship between physical activity and brain structures and functions • A chapter on the development of national and international physical activity and health guidelines, which will help readers better understand how scientific findings are converted into practical recommendations Physical Activity and Health, Second Edition, offers a detailed yet concise presentation of key concepts as well as a framework to help readers relate results from single studies or collections of studies to the overall paradigm linking physical activity and physical fitness to health. For each of the topics covered, the text provides an overview of the most important research findings, discusses the limitations of the current knowledge base, and identifies directions for future investigation. At the core of the text is a review of our current understanding of how physical activity affects health concerns such as cardiovascular disease, diabetes, cancer, and obesity as well as aging and mental health. The text identifies sedentary living habits and poor fitness as major public health problems and examines the potential of physical activity to prevent disease and enhance quality of life. This complete resource also looks at the evolution of the field of physical activity and health; variations in physical activity levels across age, sex, and ethnic groups; the body’s physiological responses to physical activity; dose-response issues; and the influence of genetics on physical activity, fitness, and health. The book ends with an integration of the issues covered and discusses new opportunities for research. The second edition of Physical Activity and Health continues to offer clear, user-friendly coverage of the most important concepts and research in the field. Numerous special features will aid readers in their comprehension of the material. Chapter outlines and callout boxes help readers key in on important topics and focus their reading, and chapter summaries, definitions of key terms, and study questions provide tools for review and self-testing. Commonly used acronyms and abbreviations are found on the interior covers for handy reference. Where other books have simply promoted physical activity for the individual or a population, Physical Activity and Health, Second Edition, completely integrates current knowledge of the relationship between physical activity and health. With contributions from some of the finest scientists in the field, this comprehensive text offers information unmatched in accuracy and reliability.




Creatine


Book Description

A comprehensive, scientific look at creatine--the supplement of choice for today's serious athletes and fitness enthusiasts--what it is, how it works, how to use it, and what it can do for an athlete. 19 photos.