Quantum‐Level Influences on Enzyme Reactions and Their Ripple Effects on Biological Phenomena

ABSTRACT Quantum mechanics describes the behavior of matter at atomic and subatomic scales. Because living organisms are ultimately composed of atoms and molecules, quantum‐mechanical effects are expected to contribute to biological phenomena. Quantum biology seeks to elucidate life processes from a quantum‐mechanical perspective. Life is sustained by chemical reactions catalyzed by numerous enzymes within cells. Hydrolytic enzyme reactions involving proton transfer from water molecules participate in nearly all biological processes. This review discusses how quantum‐level effects, including quantum tunneling, may propagate from enzymatic proton‐transfer reactions to higher‐order biological phenomena, such as DNA damage repair and gene expression. It summarizes evidence that quantum‐level mechanisms of kinetic isotope effects associated with hydrogen transfer can influence the enzymatic activity and potentially affect cellular processes.