Final answer:
Endotoxins are lipopolysaccharides released from the outer membrane of dead and dying Gram-negative bacteria. They trigger an inflammatory response and can cause severe symptoms.
Step-by-step explanation:
The lipopolysaccharides released from the outer membrane of the cell wall of dead and dying Gram-negative bacteria, whose lipid portion (lipid A) is toxic, is known as endotoxins. The lipid A component of endotoxins is responsible for their toxic properties and triggers the immune system's inflammatory response. High concentrations of endotoxins in the blood can cause severe symptoms such as a drop in blood pressure, multi-organ failure, and even death.