What is endotoxin?

Endotoxin is a toxic substance that is tightly bound to the outer membrane of the cell wall of gram-negative bacteria. It is primarily composed of lipopolysaccharides (LPS) and is released when the bacteria die or are lysed. Unlike exotoxins, which are secreted by living bacteria and can be more potent, endotoxins are released only after the bacteria are destroyed, leading to a range of biological effects including fever, inflammation, and shock in higher organisms.

Understanding endotoxin is particularly important in contexts such as medical device manufacturing and water purification systems, where the presence of endotoxin can indicate contamination and pose a significant risk to patient safety, particularly in dialysis and intravenous therapies. The measurement of endotoxin levels in purified water is crucial in ensuring that the water meets safety standards for use in medical applications.

The other options describe different concepts that do not accurately represent endotoxin. Recognizing endotoxin's source and characteristics helps in understanding its implications in health care and environmental safety.