Plasmolysis 2026-10-13
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Plasmolysis is withdrawal of the membrane-bounded contents from parts of a cell wall after water loss. A sufficiently concentrated external hypertonic solution, with solutes effectively excluded by the cell membrane over the observation time, can cause this. The cell wall remains; the enclosed material contracts. Plasmolysis is therefore distinct from osmotic lysis, which breaks the cellular boundary during excessive swelling. A return to a less concentrated surrounding chemical solution can reverse plasmolysis if the biological cell remains functional.[ref]
Figure 1.
Plasmolysis with a retained cell wall, and osmotic challenge after wall removal
. Original qualitative experiment logic. The upper pair compares a turgid plant cell with plasmolysis in an external hypertonic solution. The lower pair compares a supported protoplast with osmotic lysis after dilution for a susceptible preparation. Arrows indicate interventions or possible net water movement, not measured rates. The dilution comparison concerns lysozyme-susceptible bacteria; the upper comparison concerns plant cells. No measured dimensions, times or survival fractions are implied. Details.
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Protoplast 2026-10-13
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A protoplast is the living contents of a biological cell bounded by its cell membrane after removal of the cell wall. Removing the cell wall need not immediately destroy the cell membrane; stability depends on the preparation and surroundings. Lysozyme acts on susceptible bacterial peptidoglycan, not on cellulose or chitin, so it is not a universal wall-removal enzyme.
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