Michaelis Menten Constant `(K_(m))` is equal to

Options

A. the rate of reaction
B. the rate of enzymatic activity
C. substrate concentration at which the reaction attains half of its maximum velocity
D. substrate concentration at which the rate of reaction is maximum.

Answer

C

Explanation

`K_(m)` or the Michaelis-Menten constant is defind as the substrate concentration (expressed in moles/l) at which half-maximum velocity in an enzyme catalysed reaction is achieved. It indicates that half of the enzyme molecules (i.e. `50%`) are bound with the substrate molecules when the substrate concentration equals the `K_(m)` value. It was given by Leonor Michaelis and Maud Menten (1913). `K_(m0` value is a characteristic the strength of ES complex. A low `K_(m)` value indicates a strong affinity between enzyme and substrate, whereas a high `K_(m)` value reflects a weak affinity between them. For majority of anzyme, the `K_(m)` values in the range of `10^(-5)` to `10^(-2)` moles.