If a toxin destroys adenyl cyclase, what will be the final effect on the signaling pathway?

If a toxin destroys adenyl cyclase, what will be the final effect on the signaling pathway?

• A. The transduction step will be enhanced
• B. The receptor activation step will be accelerated
• C. The transduction step will be inhibited
• D. The cellular response will be magnified

Answer: (C)

When a toxin destroys adenyl cyclase, the final effect on the signaling pathway is the inhibition of the transduction step. Adenyl cyclase is an enzyme that converts ATP to cyclic AMP (cAMP), which acts as a second messenger in many signaling pathways. cAMP is crucial for transmitting signals from various receptors, particularly G protein-coupled receptors (GPCRs). Without adenyl cyclase, there is a significant reduction in the production of cAMP, leading to diminished activation of downstream signaling molecules and pathways that rely on cAMP for their activity. This suppression causes the transduction step, which facilitates the relay of the signal from the receptor to the target responses inside the cell, to be inhibited. On the other hand, the other options all imply an enhancement or acceleration of signaling, which contradicts the detrimental effect that the destruction of adenyl cyclase would have on the signaling pathway. The absence of cAMP impairs the ability of the cell to respond effectively to external signals. Thus, the correct understanding is that the overall transduction of the signal is inhibited as a result of adenyl cyclase destruction.

When a toxin destroys adenyl cyclase, the final effect on the signaling pathway is the inhibition of the transduction step. Adenyl cyclase is an enzyme that converts ATP to cyclic AMP (cAMP), which acts as a second messenger in many signaling pathways. cAMP is crucial for transmitting signals from various receptors, particularly G protein-coupled receptors (GPCRs).

Without adenyl cyclase, there is a significant reduction in the production of cAMP, leading to diminished activation of downstream signaling molecules and pathways that rely on cAMP for their activity. This suppression causes the transduction step, which facilitates the relay of the signal from the receptor to the target responses inside the cell, to be inhibited.

On the other hand, the other options all imply an enhancement or acceleration of signaling, which contradicts the detrimental effect that the destruction of adenyl cyclase would have on the signaling pathway. The absence of cAMP impairs the ability of the cell to respond effectively to external signals. Thus, the correct understanding is that the overall transduction of the signal is inhibited as a result of adenyl cyclase destruction.