G-protein coupled receptors (GPCRs) signal through:

A Direct enzyme activity

B Conformational change activating G proteins → second messengers (cAMP, IP3, DAG)

C Ion channels only

D Nuclear receptors

✓ Correct Answer: Option B

GPCRs: ligand binding → G protein activation (Gs stimulates, Gi inhibits adenylyl cyclase) → second messenger cascade.

💡 Why is B) the correct answer?

The correct answer to the question "G-protein coupled receptors (GPCRs) signal through:" is Option B: Conformational change activating G proteins → second messengers (cAMP, IP3, DAG).

The other options — A) Direct enzyme activity, C) Ion channels only, D) Nuclear receptors — are incorrect for this PCAT Exam Prep question. As explained above: GPCRs: ligand binding → G protein activation (Gs stimulates, Gi inhibits adenylyl cyclase) → second messenger cascade.

📚 About This PCAT Exam Prep Practice Question

This 3-level PCAT Exam Prep question from the Biological Processes topic is part of BrainForge Quiz's free exam preparation library. Each question includes the correct answer and a detailed explanation to help you understand the underlying concept, not just memorize the answer.

How to use this page: Read the question above, consider all four options (A through D), then check the highlighted correct answer and explanation. For active timed practice, start a free PCAT Exam Prep practice test or use flashcards for spaced repetition review.

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G-protein coupled receptors (GPCRs) signal through:

✓ Correct Answer: Option B

📚 About This PCAT Exam Prep Practice Question

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