cell wall

plural cell walls · alternative rare cell-wall

1. biologyA rigid, non-living structural layer located outside the cell membrane in certain cells, such as those of plants, fungi, bacteria, and some algae, providing support, shape, and protection.

   Think of the cell wall as a wicker basket in which a balloon has been inflated so that it exerts pressure from the inside. Such a basket is very rigid and resistant to mechanical damage.

   2000, John L. Howland, The Surprising Archaea: Discovering Another Domain of Life, page 70

   3 more examples

   The name of Chlamydomonas is applied to certain microscopic green bodies, each of which consists of a protoplasmic central substance invested by a structureless sac. The latter contains cellulose, as in ordinary plants; and the chlorophyll which gives the green colour enables the Chlamydomonas to decompose carbonic acid and fix carbon, as they do. Two long cilia protrude through the cell-wall, and effect the rapid locomotion of this "monad," which, in all respects except its mobility, is characteristically a plant.

   1876, T. H. Huxley, “On the Border Territory between the Animal and the Vegetable Kingdoms”, in Littell's Living Age, vol. 128, no. 1657

   The structural distinctiveness of the cell—in plants especially—is dues in large part to the presence of an outer layer, or coat, the cell wall, which in plants is usually firm, and often hard and thick; in animals, delicate or lacking.

   1947, Arthur J. Eames, Laurence H. MacDaniels, An Introduction to Plant Anatomy, 2nd edition

   Terrestrial vascular plants contain considerable quantities of lignin, an amorphous phenylpropanoid structural polymer that binds cell wall components and cell walls together providing structural stability to plants.

   1994, Robert A. Blanchette, “Lignin biodegradation in cell walls of woody plants”, in O. Petrini, G. B. Ouellette, editors, Host Wall Alterations by Parasitic Fungi, pages 55–65