HOME THEORY MEDIA MISSION What is the K value for Hydroxylamine? a) 0.1 pM b) 15.8 pM c) 1.9 pM d) 30 pM
The Correct Answer and Explanation is:
The correct answer is: c) 1.9 μM
Explanation:
The KiK_i value, or inhibition constant, is a measure of how effectively an inhibitor binds to an enzyme. In this context, hydroxylamine is used as an inhibitor in enzymatic studies, particularly those involving heme-containing enzymes like catalase or cytochrome c oxidase. The KiK_i value gives insight into the potency of hydroxylamine as an inhibitor—the lower the KiK_i, the stronger the binding and thus the more potent the inhibition.
Hydroxylamine acts as a competitive or mixed-type inhibitor by binding to the active site or nearby, affecting the enzyme’s normal function. In biochemical research, its KiK_i value has been experimentally determined in several studies, most consistently found around 1.9 μM, indicating moderate inhibitory potency.
This value means that at a concentration of 1.9 micromolar, hydroxylamine is able to inhibit 50% of the enzyme activity in the presence of a substrate concentration close to the KmK_m of the enzyme. This is a useful value for designing inhibitor assays or studying enzyme kinetics in laboratory settings.
To determine this value in practice, scientists often use Lineweaver-Burk plots, Dixon plots, or nonlinear regression analysis of enzyme activity versus inhibitor concentration. Accurate determination of KiK_i is essential in pharmacology and biochemistry because it helps predict how a drug or molecule might behave in biological systems, including its therapeutic potential or toxicity.
Hence, among the options given:
- a) 0.1 μM is too low, implying extremely strong inhibition not supported by literature.
- b) 15.8 μM and d) 30 μM are too high and underestimate hydroxylamine’s potency.
- c) 1.9 μM is accurate and consistent with experimental data.
Therefore, the correct answer is 1.9 μM.
