Maltose is a disaccharide consisting of two molecules of glucose joined together by dehydration synthesis. If onion tissue was surrounded by a solution of maltose, there would be a greater concentration of solute outside the cell relative to inside. The membrane is selectively permeable. The freshwater inside the onion cells would be in greater concentration relative to the outside environment, due to the presence of the solute. As a result, osmosis would occur and water would move out of the onion cells from high concentration inside, to low concentration outside. This effect is known as plasmolysis and the onion cell would dehydrate and shrink. The cell would lose turgor, which is the pressure of the liquid inside pressing against the cell wall. If enough fluid is lost, the rigid, non-living cell wall may even collapse.