This is no chemistry book, but a general overview of what molecules are and do, with the author focusing on the molecules of life (biochemistry). There is very little chemistry (no formula, no systematic description of the way atoms combine into molecules or how molecules interact and get modified) even if some processes are explained with references to chemical or physical concepts.
Each chapter covers a function of natural molecules( mostly biological) before examples are given of how scientists try to use those natural characteristics or processes either to try to make artificial molecules or to interact (or interfere) with nature. The book is accessible to the lay reader even if they might find some explanations more difficult, while readers with a more solid scientific education could find those descriptions a bit superficial (well, this is a "very short introduction", isn't?).
Chapter 1 is introductory (what are molecules, what they are made of, their shape and sizes, etc)
Chapter 2: The molecules of life [the cell, DNA, RNA, enzymes, proteins (role, what they are made of, how they are produced from DNA, energy that fuels the process ']
Chapter 3 : materials from molecules [structural molecules in the human body (skin, bone, muscle, hair, nails) and the proteins and enzymes that make them, with a focus on collagen. Spider silk and its hierarchical molecular arrangement that scientists have copied for artificial polymers. The animal/human cell's skeleton with its tubular structure inspiring scientists for carbon pipes)
Chapter 4 : molecules and energy (ATP and ADP molecules that provide energy for biochemical processes, mitochondria, digestion and breathing in animals/humans, photosynthesis in plants. Use of energy-rich molecules for gun powder and dynamite),
Chapter 5: molecular motors (motor proteins that create motion, allow muscle power and cell division, for instance. Optical molecular tweezers created by scientists for molecular manipulation. How motor molecules have inspired research in nanotechnologies.
Chapter 6: molecular communication (which molecule in the human body communicates with which, and what they communicate about. Hormones, neurons/axons/synapses and neurotransmitters)
Chapter 7 : molecular information (DNA' different aspects than in chapter 2'molecules that check for errors in DNA replication, or edit off useless elements before replication with scientists finding inspiration in natural editing tools for genetic modifications. Researches in molecular electronic to compensate for the limits of miniaturization of computer hardware).