Question

What are the basic functions of AB toxins and their subunits? Clinical relevance of AB toxins?

A) A subunit binds to the host cell, B subunit facilitates cellular entry; Clinical relevance includes causing diarrhea and vomiting.
B) A subunit facilitates cellular entry, B subunit binds to the host cell; Clinical relevance includes causing neurotoxicity and paralysis.
C) A subunit degrades cellular membranes, B subunit inhibits protein synthesis; Clinical relevance includes causing respiratory distress.
D) A subunit inhibits protein synthesis, B subunit degrades cellular membranes; Clinical relevance includes causing skin infections.

Answer 1

AB toxins consist of A and B subunits involved in disrupting cellular activities and facilitating cellular entry, with clinical manifestations including neurotoxicity, paralysis, and severe diarrhea.

Step-by-step explanation:

The basic functions of AB toxins are characterized by two subunits designated as A and B. The A subunit is responsible for the activity, specifically interfering with cellular functions, while the B subunit is responsible for binding to host cell receptors and facilitating the entry of the A subunit into the host cell. Examples of AB toxins include diphtheria, cholera, botulinum, and tetanus toxins, and their clinical relevance varies from toxin to toxin. For instance, diphtheria toxin inhibits protein synthesis within the host cell, cholera toxin causes severe diarrhea through the production of cyclic AMP, and botulinum toxin results in neurotoxicity and paralysis by inhibiting the release of the neurotransmitter acetylcholine.