This book provides a comprehensive exploration of medical biochemistry, bridging the gap between molecular biology and clinical medicine to deliver a complete understanding of human health and disease. It begins with an introduction to medical biochemistry, outlining fundamental concepts, principles, and the molecular basis of life, establishing a foundation for understanding the structure and function of biomolecules. The chapters on biomolecules and their medical relevance emphasize the critical roles of carbohydrates, proteins, lipids, nucleic acids, vitamins, and minerals in maintaining cellular integrity, metabolic processes, and overall physiological function, highlighting how disruptions in these molecules can lead to disease. Enzymes in medicine are examined in detail, exploring their catalytic mechanisms, regulation, and clinical applications, including their roles as biomarkers and therapeutic targets. Energy metabolism and bioenergetics are central to understanding how cells generate and utilize energy, and the book provides a thorough analysis of catabolic and anabolic pathways, mitochondrial function, and the integration of metabolic networks in health and disease. Molecular biology and medicine are covered extensively, elucidating mechanisms of DNA replication, transcription, translation, and regulation, as well as the molecular basis of inherited and acquired disorders, emphasizing how these processes inform diagnostics and therapeutic strategies. Clinical biochemistry and diagnostic tests are discussed to demonstrate how biochemical assays, enzyme measurements, metabolite analysis, and emerging molecular techniques provide crucial insights into patient health and guide clinical decision-making. The sections on hormones and endocrine biochemistry explore the synthesis, regulation, and action of hormones, as well as their effects on metabolism, growth, and homeostasis, highlighting endocrine disorders and their biochemical basis. Immunochemistry and infection address the molecular mechanisms of immune responses, antigen-antibody interactions, and the biochemical principles underlying infection, vaccination, and immunodiagnostics. Nutrition and health chapters emphasize the biochemical importance of macronutrients, micronutrients, and dietary factors in maintaining health, preventing disease, and supporting specialized physiological functions. The book also examines the biochemistry of specialized tissues, including the liver, kidney, brain, and muscle, providing insights into tissue-specific metabolism, signaling, and disease susceptibility.