In mitochondria that are actively phosphorylating in the presence of an excess of ADP, the inner membrane pulls way from the outer membrane and assumes a condensed state. In the absence of ADP, the mitochondria have the normal structure or the swollen state, in which the cristae project into the large matrix.

According to this hypothesis, the energy released during the transport of electrons along the respiratory chain causes the conformational change. The inner mitochondrial membrane, that has this energy-condensed structure, in turn, is utilised for ATP synthesis as it changes to the energy-poor swollen conformation.