Biomolecules

Chapter Overview

Biomolecules explores the chemical basis of living organisms, detailing how organic and inorganic molecules interact to form living protoplasm. The chapter starts with the fundamental types of chemical bonds in biology (ionic bonds, covalent bonds, hydrogen bonds, and hydrophobic interactions), and compares metabolic condensation (dehydration synthesis) with hydrolysis reactions in building and breaking biological polymers.

It presents an extensive evaluation of the unique physicochemical properties of water that make it the matrix of life. Students study water's polarity, solvent properties, hydrophobic exclusion, high specific heat capacity, high heat of vaporization, cohesion and adhesion dynamics, ionization behavior, and anomalous maximum density at 4°C which protects aquatic ecosystems in frozen climates.

The core macromolecules are systematically classified: carbohydrates (monosaccharides, disaccharides such as maltose, lactose, sucrose, and complex polysaccharides like starch, glycogen, cellulose, and chitin); proteins (amino acid structure, peptide bonds, primary, secondary, tertiary, and quaternary conformations, and functional roles); lipids (acylglycerols, waxes, phospholipids, terpenes, steroids, and prostaglandins); nucleic acids (DNA double helix, RNA varieties, and the central dogma of molecular biology); and conjugated molecules (glycoproteins, glycolipids, lipoproteins, and nucleoproteins) essential for membrane architecture and cell identity.