Plasmolysis. Plasmolysis is the contr action of cells within plant s due to the loss of water through osmosis. It is the cell membrane peeling off of the cell wall and the vacuole collapsing. Plasmolysis occurs when a plant cell 's membrane shrinks away from its cell wall. Plasmolysis is an effect of osmosis in plant s. Osmosis is the net diffusion of water across a selectively permeable membrane, such as a cell membrane, from an area of higher water concentration to an area of lower water concentration. Contents ... plasmolysis. shrinking of cytoplasm in a living cell caused by loss of water.