Shows what happened to a collection of frog muscles when exposed to a low concentration of the metabolic poison, sodium iodoacetate and radioactively labeled sucrose. Notice that as the ATP concentration fell, its time course of decline runs parallel to that of the falling concentration of K+ but anti-paralleled to those of the rising curves of both Na+ and sucrose. For solutes like Na+ and sucrose, which exist inside the cell at concentration below their respective concentration in the bathing solution, the extra intracellular concentration gained could be either adsorbed or free.