Ronald Whittam conducted important studies of the mechanism of active transport of ions in animal tissues. He demonstrated the special asymmetry of the ATPase of the red blood cell membrane, which acts only when Na+ is inside and K+ is outside the membrane. He was the first to demonstrate that active transport can exert a feedback control over the rate of cellular metabolism. These concepts, of directionality as an inherent part of an enzyme reaction in membranes, are of fundamental significance for the understanding of the relations between physiological function and the mechanism of enzyme action.

Professor Ronald Whittam FRS died on 16 August 2023.