Biological Functions of Carbohydrates

ISBN-13: 9789400986886 / Angielski / Miękka / 2013 / 197 str.

D. J. Candy

Opis

The study of carbohydrates in biology is one of the longest-established aspects of the subject. In consequence, it is treated in most text books of biology and biochemistry at least at an elementary level. However, certain areas of carbohydrate biochemistry have expanded rapidly over the past few years as a result of intense research activity. Such advances make this an opportune time to draw together the newer ideas of carbohydrate functions and to present them within a framework of established knowledge. This book describes the role of carbohydrates in biology at a level which is suitable for undergraduate students in biochemistry, biology and the medical sciences. The subject is treated to the final-year level although, inevitably, advanced students will wish to expand their knowledge of particular topics by use of the reading list provided as an appendix. Two areas are particularly emphasized. The first is the metabolic reactions of carbohydrates and the functions of such reactions in the organism. Here the regulation of metabolism in response to different physiological requirements is stressed, and concepts of compartmentation and transport are explored. The second area is concerned with the metabolism and functions of carbohydrate polymers. Here there has been a rapid expansion of research, particularly into the role of specific interactions of carbohydrates which occur, for example, at cell surfaces."

Spis treści

1. Chemistry of Carbohydrates.- The monosaccharides—isomerism, cyclic forms, Haworth formulae, naturally-occurring monosaccharides, sugar conformation, sugar alcohols, sugar acids, amino sugars, sugar phosphates.- Glycosides—disaccharides, polysaccharides.- Nomenclature and abbreviations.- 2. Glycolysis.- Substrates for glycolysis.- The reactions of glycolysis—hexokinase, phosphoglucomutase, glucosephosphate isomerase, 6-phosphofructokinase, aldolase, triose phosphate isomerase, glyceraldehyde 3-phosphate dehydrogenase, phosphoglycerate kinase, phosphoglyceromutase, enolase, pyruvate kinase.- Energy metabolism.- Oxidation-reduction reactions—anaerobic glycolysis, aerobic glycolysis.- Regulation of glycolysis—control reactions, regulation and energy metabolism, other regulatory factors.- Pyruvate metabolism.- 3. Other Pathways of Monosaccharide Metabolism.- Interconversion of monosaccharides—interconversion of free monosaccharides, interconversion of sugar phosphates, interconversion of nucleoside diphosphate sugars.- The pentose phosphate pathway.- The Entner-Doudoroff pathway.- Metabolism of glucuronate—L-ascorbate (vitamin C).- Myo-inositol.- Gluconeogenesis—substrates for gluconeogenesis.- The glyoxylate bypass.- 4. Photosynthesis.- The light reaction.- The dark reaction—carbon-dioxide assimilation, recycling of carbon, products of photosynthesis, associated reactions, photorespiration.- Photosynthetic microorganisms.- 5. Transport.- Transport across membranes—general types of membrane transport, passive transport in animal cells, active transport in animal cells, active transport in bacteria, group translocation in bacteria.- Transport in extracellular fluids.- 6. Glycosides and Oligosaccharides.- Biosynthesis of glycosides.- Disaccharides—trehalose, sucrose, plant oligosaccharides, lactose.- Glycosides—glycosides of plants and microorganisms, animal glycosides.- 7. Storage Polysaccharides.- Glycogen—biosynthesis, breakdown (intracellular and extracellular), liver and muscle glycogen, glycogen storage diseases.- Starch—amylose, amylopectin, biosynthesis, breakdown.- Regulation of storage polysaccharide metabolism—glycogen breakdown, glycogen synthesis, starch metabolism.- Other storage polysaccharides.- 8. Structural Polysaccharides.- Bacterial cell walls—structure, synthesis, antibiotics which interfere with cell-wall synthesis.- Plant cell walls—cellulose, matrix polysaccharides, synthesis The arthropod exoskeleton.- Mammalian connective tissues—structure of glycosaminoglycans, synthesis and breakdown.- 9. Complex Carbohydrate Polymers.- Glycoproteins—general structure, soluble and membrane-bound glycoproteins, synthesis.- Glycolipids—disorders of complex carbohydrate metabolism.- Functions of complex carbohydrates.- Specific interactions of complex carbohydrates—antigenic carbohydrates,cell surface receptors, cell—cell interactions, lectins.- 10. Hormonal Regulation.- Mammalian hormones—glucagon, insulin, adrenaline and noradrenaline, the glucocorticoids, other hormones, physiological regulation of blood glucose concentrations, diabetes.- Invertebrate hormones.- Plant hormones.- Further Reading.