Lipopolysaccharides (LPS), also known as lipoglycans, are large molecules consisting of a lipid and a polysaccharide joined by a covalent bond; they're found in the outer membrane of Gram-negative bacteria, act as endotoxins and elicit strong immune responses in animals. Functions LPS's a major component of the outer membrane of Gram-negative bacteria, contributing greatly to the structural integrity of the bacteria, and protecting the membrane from certain kinds of chemical attack. LPS also in… (More on Lipopolysaccharide)