Question

What do the values of${\mathbf{K}}_{\mathbf{M}}$and $\frac{{\mathbf{k}}_{\mathbf{cat}}}{{\mathbf{K}}_{\mathbf{M}}}$ reveal about an enzyme?

Short answer

K_M refers to the substrate concentration at which the reaction rate reaches half of its maximum velocity.The specificity constant$\frac{{\mathrm{k}}_{\mathrm{cat}}}{{\mathrm{K}}_{\mathrm{M}}}$ refers to an enzyme’s binding and catalytic efficiency.

Step-by-step solution

Introduction

Enzymes are biological catalysts that help chemical processes move faster. Enzymes are proteins that lower the amount of energyneeded to initiate a chemical reaction.

  KM reveals the enzyme

The Michaelis-Menten constant demonstrates the enzyme's affinityfor its substrate. A greater${\mathrm{K}}_{\mathrm{M}}$ indicates that an enzyme has a lower affinity for its substrate and vice versa.

 KM reveals the enzyme

The turnover number for an enzyme is ${\mathrm{k}}_{\mathrm{cat}}$, which is the rate at which the enzyme transforms the substrate into products in a unit of time. The specificity constant$\frac{{\mathrm{k}}_{\mathrm{cat}}}{{\mathrm{K}}_{\mathrm{M}}}$ represents the enzyme's binding and catalytic effectiveness.

It refers to the rate at which the enzyme-substrate complex is broken down into enzymes and products. The specificity constant $\frac{{\mathrm{k}}_{\mathrm{cat}}}{{\mathrm{K}}_{\mathrm{M}}}$becomes the second-order rate constant when the substrate concentration is significantly lower than ${\mathrm{K}}_{\mathrm{M}}$.