Enzyme specificity is given by ?

Ans. is 'a' i.e., K. The Km of an enzyme is the concentration of the substrate that enables the enzyme to function at half maximum activity and is therefore a measure of the specificity of a substrate.for the enzyme" Clinical biochemistry Actually enzyme specificity is not measured by Km alone. It is measured by the ratio Kcat/Km which is a second order rate constant for the reaction between substrate and free enzyme. This ratio is impoant, for it provides a direct measure of enzyme efficiency and specificity. Note : Kcat is turnover number and measures the rate of the catalytic process.