Michaelis-Menten kinetics is used to describe the rate of a reaction catalyzed by an enzyme as a function of the substrate concentration. This type of analysis is also commonly used to describe the rate of transporter-mediated translocation of ions and molecules across biological membranes. Test your basic knowledge of Michaelis-Menten kinetics by taking this simple quiz.
 |
 |
 |
 |
 |
— share —
(1) A lower numerical value of the Michaelis constant (Km) indicates a higher enzyme/transporter affinity for its substrate.
(2) Assume that the reaction catalyzed by an enzyme follows Michaelis-Menten kinetics. The substrate concentration (Km, Michaelis constant) needed to reach 50% of the maximum reaction velocity (Vmax) is 25 μM. Approximately, what substrate concentration is required to obtain at least 25% of the maximum reaction velocity?
(3) In Michaelis-Menten kinetics, the Michaelis constant (Km) is the substrate concentration that gives rise to a reaction velocity that is 50% of the maximum reaction velocity (Vmax).
(4) In Michaelis-Menten kinetics, the Michaelis constant (Km) provides useful information about the "apparent affinity" of the protein under study (enzyme, transporter, etc.) for its substrate.
(5) Assume that the reaction catalyzed by an enzyme follows Michaelis-Menten kinetics. If at a substrate concentration of 100 nM, the reaction proceeds at 80% of the maximum reaction velocity (Vmax), what is the Michaelis constant (Km) for this substrate. Km is the substrate concentration needed to reach 50% of Vmax.
Checking your answers...
Posted: Monday, December 15, 2014
Last updated: Tuesday, March 11, 2025
Last updated: Tuesday, March 11, 2025
— share —