Question

Michaelis constant (K${}_m$) of an enzyme which catalyses a single substrate reaction is ...

• A. Dependent upon temperature
• B. Approximately proportional to the velocity of the reaction
• C. Dependent upon enzyme concentration
• D. Dependent upon substrate concentration

Answer 1

Answer: (D)

Dependent upon substrate concentration

The Michaelis constant (K${}_m$) of an enzyme is the substrate concentration at which the reaction rate is one-half the V${}_{max}$. An enzyme with a high K${}_m$ has a low affinity for its substrate, and requires a greater concentration of substrate to achieve V${}_{max}$.

So, the correct answer is option D.