Consisting of the core, O antigen, and Lipid A, this amphipathic molecule is found on the outer leaflet of the membranes of gram negative bacteria.  
This substance is one of the causes of the Schwartzman reaction and, following its massive release into the blood stream, it activates B cells and induces macrophages to release interleukin-1, interleukin-6, and tumor necrosis factor. Consisting of the core, O antigen, and Lipid A, this amphipathic molecule is found on the outer leaflet of the membranes of gram negative bacteria.  For 10 points - name the substance essential for bacterial viability that is the major bacterial instigator of sepsis and fever.
This substance is one of the causes of the Schwartzman reaction and, following its massive release into the blood stream, it activates B cells and induces macrophages to release interleukin-1, interleukin-6, and tumor necrosis factor.
lipopolysaccharide or LPS or endotoxin