A receptor that binds to a ligand at very low concentrations has a
A)high dissociation constant.
B)low Kₐ.
C)high affinity for the ligand.
D)low affinity for the ligand.

Question

Quizplus · Accepted Answer

A receptor that binds to a ligand at very low concentrations has high affinity for the ligand. The dissociation constant (Kd) is a measure of the strength of the interaction between a ligand and its receptor, and is the concentration of ligand at which half of the receptors are occupied. A low Kd indicates high affinity, while a high Kd indicates low affinity. Therefore, choice A is incorrect. Similarly, choice B is incorrect, as a low Ka indicates high affinity. Therefore, the correct answer is choice C. Choice D is also incorrect, as a low affinity receptor would not bind the ligand at very low concentrations.

A Receptor That Binds to a Ligand at Very Low