Question

An enzyme that follows Michaelis-Menten kinetics has a KM value of 15.0 μM and a kcat value of 221 s−1. At an initial enzyme concentration of 0.0100 μM, the initial reaction velocity was found to be 1.07×10−6 μM/s. What was the initial concentration of the substrate, [S], used in the reaction ?

Answer 1

Answer:5

$7.26\times 10^{-6}$μM is the initial concentration of the substrate, [S], used in the reaction.

Explanation:

Michaelis–Menten 's equation:

$v=V_{max}\times \frac{[S]}{(K_m+[S])}=k_{cat}[E_o]\times \frac{[S]}{(K_m+[S])}$

$V_{max}=k_{cat}[E_o]$

v = rate of formation of products =$1.07\times 10^{-6}$ μM/s

[S] = Concatenation of substrate = ?

$[K_m]$ =  Michaelis constant = 15.0 μM

$V_{max}$ = Maximum rate achieved

$k_{cat}$ = Catalytic rate of the system = 221 $s^{-1}$

$[E_o]$ = Initial concentration of enzyme. =0.0100 μM

On substituting all the given values:

$[S]=7.26\times 10^{-6}$μM

$7.26\times 10^{-6}$μM is the initial concentration of the substrate, [S], used in the reaction.