Question

Which statement about exotoxins is true?

A) exotoxins are contained in cell walls of gram-negative bacteria
B) exotoxins are released during the lysis of bacteria
C) exotoxins are able to initiate the complement and coagulation cascades
D) exotoxins are released during bacterial growth

Answer 1

Exotoxins are protein molecules released during bacterial growth and are mainly secreted by gram-positive bacteria, but also by some gram-negative bacteria. They are specific in their action and much more potent than endotoxins.

Step-by-step explanation:

Among the statements provided about exotoxins, the correct statement is that exotoxins are released during bacterial growth. Exotoxins are protein molecules produced by pathogenic bacteria. They are very specific in their action, targeting particular cells and receptors with unique molecular mechanisms. Unlike endotoxins that are found in the cell walls of gram-negative bacteria and released upon lysis, exotoxins are secreted mostly by gram-positive bacteria and can also be produced by gram-negative bacteria. Exotoxins are more potent and can be lethal at very lower concentrations compared to endotoxins. The heat labile nature of exotoxins means they are often denatured at temperatures that would not affect the stability of endotoxins.