The plasma membrane is at once the window through which the cell senses the environment and the portal through which the environment influences the structure and activities of the cell. Its importance in cellular physiology can thus hardly be overestimated, since constant flow of materials between cell and environment is essential to the well-being of any biological system. The nature of the materials movÂ ing into the cell is also critical, since some substances are required for maintenance and growth, while others, because of their toxicity, must either be rigorously excluded or permitted to enter only after chemical alteration. Such alteration frequently permits the compounds to be sequestered in special cellular compartments having different types of membranes. This type of homogeneity, plus the fact that the wear and tear of transmembrane molecular traffic compels the system to be constantly monitored and repaired, means that the membrane system of any organism must be both structurally complex and dyÂ namic. Membranes have been traditionally difficult to study because of their fragility and small diameter. In the last several decades, however, remarkable advances have been made because of techniques permitÂ ting the bulk isolation of membranes from homogenized cells. From such isolated membranes have come detailed physical and chemical analyses that have given us a detailed working model of membrane. We now can make intelligent guesses about the structural and funcÂ tional interactions of membrane lipids, phospholipids, proteins, sterols and water.
This book is a textbook (it includes, for example, exercises and outline solutions). The plant scientist is shown how to express physiological ideas mathematically and how to deduce quantitative conclusions, which can then be compared with experiment. There is little new biology in the book, but it is presented in a way that will be new to many biologists. The matching of models to experiments means using mathematics for formulating biological concepts and second, using algebra, calculus, or, now more frequently, computers to solve or simulate the resulting model; and finally, comparing, qualitatively or quantitatively, prediction to measurement. Computers are the important enabling technology that makes it all possible: solving equations, assembling models of increasing sophistication and complexity, and comparing theory with experiment. The book is divided into three parts. Part I. Covers subjects of wide relevance to modelling and plant biology. Part II. The reader may choose to select topics of particular interest from part II. However, the whole-plant modeller will need to study all chapters, and the plant ecosystem modeller may need to add other material also. Part III. Plant morphology is at an introductory level. It is included because morphological characters may prove to be of equal importance to some physiological traits in determining plant function and performance. "This textbook presents, in an interesting and clearly written fashion, a mathematical approach to a wide range of topics in plant and crop physiology, including light interception, leaf and canopy photosynthesis, respiration, partitioning, transpiration and water relations, branching and phyllotaxis. The biochemistry of plant growth and maintenanace is also presented in some detail. I was very pleased with the text, especially with the philosophy presented by the authors that biological models are necessarily simplifications of complex detail. I would strongly recommend it for reading and consultation by graduates and research workers." J. Exp. Botany "The authors' approach succeeds admirably, giving a thorough account of the mathematical toolbox available to researchers and the areas in which those tools have been used." Plant, Cell and Environment "Combining considerable technical cleverness with creativity and the refreshing notion that science is a "common-sense, unpredictable, fascinating and thoroughly human activity." Times Higher Educational Supplement "Exceptionally scholarly volume. Logical and systematic. Authors have assembled a mass of mathematical material in an elegant layout." Agricultural Systems
This volume surveys the chemistry, biochemistry, biosynthesis, metabolism and pharmacological properties of lectins. Lectins, which are most commonly found in plants, are widespread natural products with striking biological activities. Their specific ability to recognise and bind to simple or complex saccharides facilitates their role as effective information protein molecules. As agents of cell-to-cell recognition, lectins promote symbiosis between plants and specific nitrogen-fixing soil bacteria. As natural defensive molecules, they can protect plants against predators such as bacteria, fungi and insects. As part of our diet, lectins are powerful exogenous growth factors in the small intestine and influence our health, the digestive function and the bacterial ecology of the alimentary tract. Lectins are also important research tools in preparative biochemistry and cell science.
Jessica was eight years old and she had a secret. It wasn't a normal secret, like the surprise birthday present you buy for your mum, or the secret codeword that gets you into the club that you and your friends made. No, Jessica was a werewolf! Join Jessica and her friends as they help save Father Christmas in the case of the Cancelled Christmas...
Lift-off wordless books (Lilac band) ensure all children develop the essential early language skills for reading readiness. Alpa and Lok are at the park with Bruce the dog, who loves to chase every sound he hears. Follow Bruce's journey through the park and the trail of chaos he leaves behind!
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