1.1 Distinctive Properties of Living Systems 1.2 Biomolecules: The Molecules of Life 1.3 A Biomolecular Hierarchy: Simple Molecules Are the Units for Building Complex Structures 1.4 Properties of Biomolecules Reflect Their Fitness to the Living Condition 1.5 Organization and Structure of Cells 1.6 Viruses Are Supramolecular Assemblies Acting as Cell Parasites