Binding affinity is defined as what?

Binding affinity is defined as what?

• A. A measure of the drug's solubility
• B. A measure of the attraction force between the receptor and the drug
• C. A measure of the drug's color
• D. A measure of the rate at which the drug is metabolized

Answer: (B)

Binding affinity describes how strongly a drug binds to its receptor—the attraction between the receptor and the drug. A higher affinity means the drug binds more tightly and can occupy receptors at lower concentrations. This is quantified by binding constants like Kd or pKi. It’s a measure of interaction strength, not properties like solubility, color, or how fast the drug is metabolized. While higher affinity often influences potency, affinity and efficacy are related but distinct concepts.

Binding affinity describes how strongly a drug binds to its receptor—the attraction between the receptor and the drug. A higher affinity means the drug binds more tightly and can occupy receptors at lower concentrations. This is quantified by binding constants like Kd or pKi. It’s a measure of interaction strength, not properties like solubility, color, or how fast the drug is metabolized. While higher affinity often influences potency, affinity and efficacy are related but distinct concepts.