plants rely on osmosis to support stems and leaves. water moves into plant cells by osmosis, this causes vacuole to swell, which presses cytoplasm against plant cell wall. pressure builds up until no more water can physically enter cell- this pressure is turgor. turgor pressure makes cells hard and rigid, in turn keeping leaves and stems of plant rigid and firm
plants need fluid surrounding cells to always be hypotonic to cytoplasm, with lower conc of solutes and higher conc of water than plant cells themselves. this keeps water moving by osmosis in right direction and cells are turgid. if solution surrounding plant cells is hypertonic to cell contents, water will leave cells by osmosis and cells will no longer be firm and swollen- they become flaccid(soft) as no pressure in cell walls, so plant wilts as turgor no longer supports plant tissues
if more water lost by osmosis, vacuole and cytoplasm shrink, and eventually cell membrane pulls away from cell wall
plasmolysis- plasmolysed cells die quickly unless osmotic balance is restored
