Endotoxin, also known as ___________, is part of the outer (wall) membrane of Gram-negative bacteria.

Verified step by step guidance

1. Understand that endotoxins are toxic components associated with the outer membrane of Gram-negative bacteria.
2. Recall that the outer membrane of Gram-negative bacteria contains lipopolysaccharides (LPS), which are large molecules consisting of a lipid and a polysaccharide.
3. Recognize that the toxic part of the lipopolysaccharide is called lipid A, which is responsible for the endotoxin activity.
4. Therefore, the term 'endotoxin' refers specifically to the lipopolysaccharide (LPS) complex found in the outer membrane of Gram-negative bacteria.
5. Summarize that endotoxin = lipopolysaccharide (LPS), a key structural and toxic component of the Gram-negative bacterial outer membrane.

Key Concepts

Endotoxin

Endotoxins are toxic components found in the outer membrane of Gram-negative bacteria. They are released when the bacteria die or their cell walls break down, triggering strong immune responses in the host.

Lipopolysaccharide (LPS)

Lipopolysaccharide (LPS) is the chemical structure that constitutes endotoxin. It consists of lipid A, a core polysaccharide, and an O antigen, and is responsible for the toxic effects associated with endotoxins.

Gram-negative Bacterial Cell Wall

Gram-negative bacteria have a unique cell wall structure with an outer membrane containing LPS, a thin peptidoglycan layer, and an inner membrane. This structure differentiates them from Gram-positive bacteria and is key to endotoxin presence.