Crenation
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Crenation (from modern Latin crenatus meaning "scalloped or notched", from popular Latin crena meaning "notch")[1] in botany and zoology, describes an object's shape, especially a leaf or shell, as being round-toothed or having a scalloped edge.[1]
The descriptor can apply to objects of different types, including cells, where one mechanism of crenation is the contraction of a cell after exposure to a hypertonic solution, due to the loss of water through osmosis.[2]: 229–230 In a hypertonic environment, the cell has a lower concentration of solutes than the surrounding extracellular fluid, and water diffuses out of the cell by osmosis, causing the cytoplasm to decrease in volume. As a result, the cell shrinks and the cell membrane develops abnormal notchings. Pickling cucumbers and salt-curing of meat are two practical applications of crenation.[2]: 229
Plasmolysis is the term which describes plant cells when the cytoplasm shrinks from the cell wall in a hypertonic environment. In plasmolysis, the cell wall stays intact, but the plasma membrane shrinks and the chloroplasts of the plant cell concentrate in the center of the cell.