The Michaelis-Menten equation expresses the relationship between the concentration of substrate and reaction rate. When the concentration is small, the rate is proportional to substrate concentration. When the concentration of substrate so large that it saturates the enzyme, the rate is maximal and no longer increases with greater substrate concentration. The equation rests on a model of enzyme activity where the rate is conceived as depending on the concentration of enzyme substrate complex, a concentration which is one side of the thermodynamic equilibrium between substrate and enzyme. The maximal rate (Vmax) occurs when the enzyme sites are saturated with substrate. Allosteric enzymes do not conform to the Micheaelis-Menten model because the binding of substrate to one active site can affect the properties of other active sites on the same enzyme molecule. Additionally, competitive inhibition does not change Vmax (the competitive inhibitor can be overcome by high substrate concentration), although with noncompetitive inhibition, Vmax does change.

While you definitely need to have a basic familiarity with Michaelis-Menten kinetics, very difficult enzyme kinetics questions would have a hard time finding their way onto the MCAT because it would produce too great an advantage for students who have taken biochemistry.












The WikiPremed MCAT Course is a comprehensive course in the undergraduate level general sciences. Undergraduate level physics, chemistry, organic chemistry and biology are presented by this course as a unified whole within a spiraling curriculum. Please read our policies on Privacy and Shipping & Returns.  Contact Us. MCAT is a registered trademark of the Association of American Medical Colleges, which does not endorse the WikiPremed Course. WikiPremed offers the customers of our publications or our teaching services no guarantees regarding eventual performance on the MCAT.


Creative Commons License
WikiPremed is a trademark of Wisebridge Learning Systems LLC. The work of WikiPremed is published under a Creative Commons Attribution NonCommercial ShareAlike License. There are elements of work here, such as a subset of the images in the archive from WikiPedia, that originated as GNU General Public License works, so take care to follow the unique stipulations of that license in printed reproductions.