Final answer:
A-B toxins consist of an active A subunit that disrupts cellular functions and a binding B subunit that targets specific cells. A-B toxins can have various effects depending on the cell type, such as inhibiting protein synthesis or neurotransmitter release.
Step-by-step explanation:
Understanding A-B Toxin Components
A-B toxins are comprised of two distinct components: the A subunit (activity) and the B subunit (binding). The A subunit is responsible for disrupting internal cellular functions once inside the host cell. It typically acts enzymatically to alter specific cellular processes, which can lead to cell death or dysfunction. Examples include inhibition of protein synthesis or cleavage of cellular proteins necessary for vital functions. The B subunit, on the other hand, targets the toxin to specific cells by binding to cell surface receptors. This binding facilitates the toxin's entry into the cell via endocytosis.
Different A-B toxins affect different cell types and functions, such as the diphtheria toxin targeting protein synthesis and botulinum toxin affecting neurotransmitter release. Understanding the precise functions of the A and B subunits provides crucial insight into the molecular basis of how these toxins exert their effects and how treatments can be developed.