Kcat/km is a measure of

Kcat/km is a measure of -
a) Enzyme efficiency
b) Speed of enzymatic reaction
c) Concentration of substrate
d) Enzyme turn over
Correct Answer - D
Answer-D. Enzyme efficiency
“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” .
Actually enzyme specificity is not measured by alone.
It is measured by the ratio Kcat /Km which is a second order
rate constant for the reaction between substrate and free
This ratio is important, for it provides a direct measure of
enzyme eficiency and specificity.
Note: Km, is turnover number and measures tJre rate of the
catalytic process