The Role of Adenosine Triphosphate in Transport Reactions

The evidence bearing on the participation of adenosine triphosphate (ATP) in transport reactions is reviewed. The connection may take the form of a strict quantitative relationship as observed in potassium uptake by red blood cells or as in amino acid uptake by slices of rat brain cortex. There may also be a qualitative relationship such as that observed in studies of amino acid uptake by Ehrlich ascites carcinoma cells. In other tissues (e.g. slices of the Ehrlich carcinoma) amino acid uptake may only have an uncertain relationship to the ATP content of the tissue. Some of the schemes which have been put forward to account for the involvement of ATP are discussed.