Question

The Michaelis constant for urease at room temperature is 2.0 mM, and k2-2.5x 104 s-1 at phH 7.5. Calculate the initial rate of the reaction when the urea concentration is 0.025 mM and the urease concentration is 7.O uM 1.8 x 10-3 M s1 O 2.2 x 10-3 M s1 3.4 x 10-3M s1 5.7 x 10-3 M s-1 Question 4 (2 points) The rate constant for a pseudo-first-order reaction is 0.122 s1. Find the initial concentration of the reactant if its rate of disappearance 15.00 s after the initiation of the reaction is 3.84x 104 M s-1 8.51 x 103 M 1.96 x 10 2 M 0.0196 x 10 3 M 8.51 M

Answer 1

E + S $\leftrightharpoons$ ES . Rate constants k₁ and k₁^{​​​​​​}' .

ES$\rightarrow$ P. Rate constant = k₂

K_M = k₁/(k₁'+ k₂)

[S] = [urea] = 0.025mM = 0.025×10^-3M

[E] = [urease] = 7.0×10^-6M

Rate of reaction = k₂[ES]

Q4: based on rate of disappearance of reactant , we can calculate concentration of reactant at that time. Then we can apply the integral rate law to calculate initial concentration of reactant.

For calculations see the picture below :

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