Question

Which one value is required for enzyme action?

• A. Low $K_m$
• B. High $K_m$
• C. Low $K_i$
• D. High $K_i$

Answer 1

Answer: (C)

Low $K_i$

K${}_i$ is the inhibitory constant. It is the estimation of the potency of an inhibitor. When the K${}_i$ is is low the inhibitor binds very tightly to the enzymes and the rate of reaction slows down and the required dose of the inhibitor is very less. High K${}_i$ decreases the binding affinity of the inhibitor and thus rate of reaction increases and the inhibitor is required in very large quantity.

So, the correct answer is option C.