Chapter 14, Problem 14.36P

Interpretation Introduction

Interpretation:

The change in rate of an enzyme catalyzed reaction when substrate concentration is changed from $1.4\times {10}^{-5}\text{M}$ to $3.4\times {10}^{-5}\text{M}$ needs to be determined.

Concept introduction:

Mechanism of enzyme catalyst reaction is as follows:

$\text{E+S}\underset{k_{-1}}{\overset{k_1}{\rightleftarrows }}\text{ES}\left(\text{fast}\right)$ ...... (1)

$\text{ES}\stackrel{k_2}{\to }\text{E+P}\left(\text{slow}\right)$ ...... (2)

Here, slow step is rate determining step.

To get overall balanced reaction add equation (1) and (2).

$\begin{array}{l}\text{E+S}\underset{k_{-1}}{\overset{k_1}{\rightleftarrows }}\text{ES}\\ \text{ES}\stackrel{k_2}{\to }\text{E+P}\\ \text{E+S}\stackrel{k}{\to }\text{E+P}\end{array}$

Therefore, overall reaction is as follows:

$\text{E+S}\stackrel{k}{\to }\text{E+P}$