Chapter 1: Biochemistry: An Evolving Science

A significant portion of the material focuses on the chemical concepts necessary for understanding biological stability, distinguishing between strong covalent bonds and the essential roles of four types of weak noncovalent interactions: ionic interactions, hydrogen bonds, van der Waals forces, and the hydrophobic effect. The summary explains how the unique properties of water, including its polarity and high dielectric constant, influence these interactions, driving phenomena such as the aggregation of nonpolar molecules to release ordered water and maximize entropy. The lecture further explores the laws of thermodynamics, defining energy conservation and the inevitable increase of entropy, and applies Gibbs free energy to predict the spontaneity of biochemical processes, such as the heat-releasing formation of the double helix. Additionally, the text covers essential acid-base chemistry, defining pH and pK values, and detailing how buffers like the phosphate system resist pH changes, a process quantified by the Henderson-Hasselbalch equation. Finally, the overview addresses the modern genomic revolution, describing how high-throughput sequencing has transformed medicine and biology by enabling comparative genomics, the study of the human microbiome, and a deeper understanding of how genetic predispositions interact with environmental factors like nutrition to influence health and disease.