5. 2 Early history of the study of glucose metabolism 101 5. 3 The Embden-Meyerhof pathway 104 5. 4 Biological significance of the glycolytic pathway 107 5. 5 Glycogen and other polysaccharides 110 5. 6 Other monosaccharides 115 5. 7 The pentose phosphate pathway 116 5. 8 Overview 122 Answers to exercises 123 Questions 123 6 Lipids: breakdown of fatty acids; brown fat; ruminant metabolism 125 6. 1 Introduction 125 6. 2 Triacylglycerols as energy reserves 125 6. 3 Oxidation of fatty acids 126 6. 4 Thermogenesis 129 6. 5 Ruminant metabolism 133 6. 6 Overview 137 Answers to exercises 137 Questions 138 7 Amino acid catabolism 139 7. 1 Introduction 139 7. 2 Protein degradation 139 7. 3 Removal of nitrogen from amino acids 141 7. 4 Essential amino acids 144 7. 5 Carbon chain catabolism 146 7. 6 Interconversion of amino acids and transamination 150 7. 7 Pathways for nitrogen excretion 155 7. 8 Biosynthesis of urea 156 7. 9 Overview 160 Answers to exercises 160 Questions 160 Answers to questions 162 Glossary 167 Index 169 vi Contents / / '--------------' Editors' Foreword This book is one of a series of brief fundamental·· texts for junior undergraduates and diploma students in biological science. The series, Molecular and Cell Biochemistry, covers the whole of modem biochemistry, integrating animal, plant and microbial topics.