In most algae, bacteria, and fungi, the structure which forms a (usually rigid) layer external to the cell membrane; responsible for the shape of the organism and for protecting it from mechanical damage, osmotic lysis, etc; may also serve as a permeability barrier to antibiotics and other substances.

The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.

The rigid or semi-rigid envelope lying outside the cell membrane of plant, fungal, most prokaryotic cells and some protozoan parasites, maintaining their shape and protecting them from osmotic lysis. In plants it is made of cellulose and, often, lignin; in fungi it is composed largely of polysaccharides; in bacteria it is composed of peptidoglycan; in protozoan parasites such as Giardia species, it's made of carbohydrates and proteins.

Cell wall, specialized form of extracellular matrix that surrounds every cell of a plant. The cell wall is responsible for many of the characteristics that distinguish plant cells from animal cells. Although often perceived as an inactive product serving mainly mechanical and structural purposes...