Exotoxins

Definition

Exotoxins are toxic proteins secreted by certain bacteria that can cause damage to the host by destroying cells or disrupting normal cellular metabolism. They are typically associated with specific symptoms in infections of the gastrointestinal tract.

5 Must Know Facts For Your Next Test

1. Exotoxins can be produced by both Gram-positive and Gram-negative bacteria.
2. Cholera toxin, produced by Vibrio cholerae, is a well-known exotoxin that causes severe diarrhea.
3. Exotoxins are often heat-labile, meaning they can be deactivated by heating.
4. These toxins are highly potent and can act at very low concentrations.
5. Exotoxins can be categorized into three main types: cytotoxins, neurotoxins, and enterotoxins.

Review Questions

• What type of bacteria (Gram-positive or Gram-negative) can produce exotoxins?
• Name an example of an exotoxin involved in gastrointestinal infections and its associated disease.
• Why are many exotoxins considered heat-labile?

Related terms

Endotoxins: Toxic components of the outer membrane of certain Gram-negative bacteria released only when the bacteria die.

Enterotoxin: A type of exotoxin that targets the intestines, causing symptoms like vomiting and diarrhea.

Cytotoxin: A type of toxin that kills or damages individual cells within the host.