The proton motive force (PMF) is a critical concept in cellular bioenergetics, particularly within the context of mitochondrial function. It refers to the electrochemical gradient generated across the inner mitochondrial membrane due to the action of the electron transport chain (ETC). This gradient is composed of two components: a difference in proton concentration (pH gradient) and an electric potential difference (membrane potential). Together, these components drive the synthesis of adenosine triphosphate (ATP), which is vital for various cellular processes.
