Chemiosmosis is a biological process involved in moving protons across a biological membrane, generating a proton gradient that drives the production of ATP (adenosine triphosphate) molecules. ATP is the primary energy currency in cells. It provides the energy that cells need to carry out various cellular activities. Chemiosmosis plays a pivotal role in aerobic and anaerobic cellular respiration as well as photosynthesis, both critical life-sustaining processes.