Which has the strongest affinity when k−1 is greater than k2?
A) 150 mM
B) 0.15 mM
C) 150 μM
D) 1.5 nM
E) 15,000 pM

Question

Which has the strongest affinity when k−1 is greater than k2?
A) 150 mM
B) 0.15 mM
C) 150  μM
D) 1.5 nM
E) 15,000 pM

Quizplus · Accepted Answer

The equation for affinity (Ka) is Ka = k2/k-1. If k-1 is greater than k2, then the denominator is larger than the numerator, resulting in a smaller Ka. This means the dissociation constant (Kd) is larger, indicating lower affinity. The smallest Kd indicates the strongest affinity, so we want the largest Ka.

Out of all the choices, option D (1.5 nM) has the smallest Kd, meaning it has the highest affinity. Therefore, the answer is D.

Which Has the Strongest Affinity When K−1 Is Greater Than