"Life on the Edge - Chapter 3" explores the role of enzymes as biological catalysts, driving life's processes at a molecular level. The chapter discusses how enzymes like collagenase work, using the example of tadpole tail resorption and dinosaur fossil analysis to illustrate their function. Quantum mechanics is introduced as a potential explanation for how enzymes achieve their efficiency, with a focus on the quantum tunneling of electrons and protons. The text examines the kinetic isotope effect and experiments that support the idea of quantum tunneling in enzyme reactions. It also touches upon the complexities of quantum effects within the chaotic environment of living cells, considering them crucial for life's processes. Finally, the chapter looks at cellular respiration as a series of quantum events, showing that electrons travel vast distances without the usual energy-sapping effects of going across such large gaps.