Question

How are endo and exotoxins different with regard to temperature?

a) Endotoxins are heat-stable, exotoxins are heat-labile
b) Endotoxins are heat-labile, exotoxins are heat-stable
c) Both are heat-stable
d) Both are heat-labile

Answer 1

Endotoxins are heat-stable and require heating to 121 °C for inactivation, whereas exotoxins are heat-labile and can be inactivated at temperatures above 41 °C.

Step-by-step explanation:

The difference between endo and exotoxins with regard to temperature stability is that endotoxins are heat-stable, meaning they remain stable at high temperatures, and require heating at 121 °C (250 °F) for 45 minutes to inactivate. Exotoxins, on the other hand, are heat-labile because they are protein structures and are generally denatured (inactivated) at temperatures above 41 °C (106 °F). Therefore, the correct answer is: a) Endotoxins are heat-stable, exotoxins are heat-labile.