Mold Remediation Certification Practice Exam

Toxins associated with gram-negative bacteria are known as what?

1. Exotoxins

2. Endotoxins

3. Cytotoxins

4. Neurotoxins

The correct answer is: Endotoxins

Toxins associated with gram-negative bacteria are referred to as endotoxins. Endotoxins are typically components of the bacterial cell wall, specifically lipopolysaccharides (LPS) found in the outer membrane of gram-negative bacteria. When these bacteria are lysed or killed, endotoxins are released into the surrounding environment, which can trigger significant immune responses in humans and other mammals. The reason endotoxins are particularly noteworthy is that they can lead to severe reactions such as fever, inflammation, and shock, which are serious health concerns. This contrasts with exotoxins, which are proteins secreted by bacteria and can have more specific effects at the cellular level. Cytotoxins and neurotoxins, while they are types of exotoxins, have specific targets and effects - cytotoxins typically target and kill cells, while neurotoxins specifically affect nerve cells. However, the general category for the toxins released from gram-negative bacteria, as classified by their structure and source, is endotoxins. Thus, identifying them correctly reinforces an understanding of the relationship between bacterial structure and the types of toxins they can produce.