The fourth edition of Textbook of Biochemistry is a comprehensive introduction to the basic concepts of biochemistry for undergraduate students of medicine. It covers all the topics and core competencies specified by the MCI in its 'competency-based undergraduate curriculum' effective from August 2019. The topics are developed in a manner that encourages students to think analytically as opposed to memory-based learning. Links between biochemistry and other medical subjects provided throughout the book help to reinforce this approach. A consistent feature of the book is the liberal use of illustrations, tabular layouts and highlighted text, which makes the assimilation and recall of the inherently complex aspects of biochemistry easy. In this edition, descriptions of topics which may fall under the category of additional reading have been set off from the regular text in a smaller font size to distinguish them from the essential content. This feature, along with comprehensive chapter summaries will help students to optimise the time spent in revising for examinations. The chapter-end exercises comprising review questions, MCQs, case studies, riddles and other problems will further enhance the revision experience. The problems-based exercises and case studies often reveal additional insights on the core concepts covered in the book. Contents: I Prelude — Molecular and Functional Organisation of Life 1. Learning Biochemistry 2. The Cell and Biological Membranes: Structure and Function II Molecules of Life 3. Carbohydrates 4. Lipids 5. Amino Acids and Proteins 6. Nucleotides and Nucleic Acids 7. Enzymes 8. Vitamins III Physiological Biochemistry 9. Biochemistry of Blood 10. Hemoglobin: Chemistry of Respiration 11. Heme Synthesis and Degradation 12. Digestion and Absorption IV Metabolism 13. A Journey into Metabolism 14. Central Metabolism: Biological Oxidation 15. Metabolism of Carbohydrates 16. Metabolism of Lipids 17. Metabolism of Amino Acids 18. Metabolism of Nucleotides 19. Integration of Metabolism 20. Metabolism of Xenobiotics: Detoxification V Nutrition 21. Minerals 22. Principles of Nutrition VI Clinical Biochemistry 23. Water and Electrolytes 24. Acid–Base Balance 25. Organ Function Tests 26. Biochemistry of Cancer VII Molecular Biology 27. DNA Metabolism 28. RNA Metabolism 29. Protein Biosynthesis 30. Regulation of Gene Expression VIII Biotechnology and Immunology 31. Recombinant DNA Technology 32. Molecular Biology Techniques 33. Biochemical Techniques 34. Immunochemistry IX Biochemical Perspective of Endocrinology 35. Hormone Action 36. Hypothalamic and Pituitary Hormones 37. Thyroid Hormones 38. Hormones of the Adrenal Gland 39. Hormones of the Gonads 40. Hormones of the Pancreas and Diabetes Mellitus X Contemporary Topics 41. Extracellular Matrix 42. Reactive Oxygen Species and Antioxidants 43. Biochemical Genetics 44. Environmental Pollutants, Toxins and Biomedical Waste Management 45. Human Genome Project and Bioinformatics 46. Gene Therapy Key to MCQs Appendix: Reference Values and Interpretation of Biochemical Parameters for Ready Clinical Reference Index