Chapter 8, Problem 38P

Interpretation Introduction

(a)

Interpretation:

The enzyme that has the higher affinity for substrate should be determined.

Concept introduction:

Michaelis Menten model describes the kinetic properties of enzymes. Enzyme and substrate combines to form an enzyme-substrate complex and form a product or it can go back to dissociated enzyme and substrate.

$\text{E + S}\underset{k_{-1}}{\overset{k_1}{\rightleftharpoons }}\text{ ES }\stackrel{k_2}{\to }\text{ E + P}$

The rate of formation of product V₀ is given by Michaelis-Menten equation,

${\text{V}}_0={\text{V}}_{\max }\frac{\left[\text{S}\right]}{\left[\text{S}\right]+K_M}$

The reaction rate when the enzyme is fully saturated with substrate is said to be V_max. K_M is the Michaelis constant which is the substrate concentration at the half of the V_max.

Interpretation Introduction

(b)

Interpretation:

The initial velocity of the reaction should be determined when catalyzed by the wild type enzyme at the 10 mM substrate concentration.

Concept introduction:

K_M is the Michaelis constant which is the substrate concentration at the half of the V_max.

Interpretation Introduction

(c)

Interpretation:

Enzyme that varies the equilibrium more in the product direction should be determined.

Concept introduction:

Enzymes act as catalysts which increase the rate of the reaction by lowering the activation energy. Most of the enzymes are proteins.