Does sucrose space exist?

Abstract

Subcellular organelles, on isolation in sucrose media, have sucrose in the inner space. The paradoxical observations of osmotic behaviour in the presence of external sucrose and rapid kinetics of entry of sucrose in mitochondria have led to the postulation of a two-compartment model, i.e. sucrose space hypothesis. A critical reappraisal of earlier work has suggested the alternative hypothesis of altered permeability of biological membranes to sucrose during centrifugation. Based on the robust physical theory of osmosis, direct experimental strategies are evolved to evaluate the sucrose space hypothesis. Some of the theoretical and experimental consequences of gravity-mediated entry of sucrose are explored.