yeast mitochondrial adpatp carriers are monomeric in detergents mitochondrial carriers are believed widely to be homodimers both in the inner membrane of the organelle and in detergents the dimensions and molecular masses of the detergent and proteindetergent micelles were measured for yeast adpatp carriers in a range of different detergents the radius of the carrier at the midpoint of the membrane its average radius its stokes radius its molecular mass and its excluded volume were determined these parameters are consistent with the known structural model of the bovine adpatp carrier and they demonstrate that the yeast mitochondrial adpatp carriers are monomeric in detergents therefore models of substrate transport have to be considered in which the carrier operates as a monomer rather than as a dimer