Which term describes a compound that activates only a subset of a receptor's signaling pathways?

Which term describes a compound that activates only a subset of a receptor's signaling pathways?

• A. Agonist
• B. Full agonist
• C. Biased agonist
• D. Inverse agonist

Answer: (C)

A biased agonist. In receptor signaling, a ligand can activate multiple downstream pathways. A biased agonist stabilizes a receptor conformation that preferentially engages only certain signaling routes (functional selectivity), so it triggers some pathways strongly while others are weakly or not activated. This is different from a full agonist, which tends to maximize signaling across pathways, and from an inverse agonist, which reduces constitutive activity. A partial agonist produces a submaximal response overall, not necessarily selective for particular pathways.

A biased agonist. In receptor signaling, a ligand can activate multiple downstream pathways. A biased agonist stabilizes a receptor conformation that preferentially engages only certain signaling routes (functional selectivity), so it triggers some pathways strongly while others are weakly or not activated. This is different from a full agonist, which tends to maximize signaling across pathways, and from an inverse agonist, which reduces constitutive activity. A partial agonist produces a submaximal response overall, not necessarily selective for particular pathways.