Kat Thomson

What MCAT Enzymes Do I Need to Know?

Apple and vinegar representing MCAT enzymes - image by Magoosh

Curious about the enzyme kinetics MCAT content you’ll find on the Bio/Biochem section? We’ve got you covered! Below is a quick overview of MCAT enzymes to know as well as enzyme classification, features, regulation, and more. Also check out this guide to the most common MCAT topics you’ll find on the test as well as this guide to the bio and biochem section of the MCAT.

For a handy PDF version of this material, as well as more great MCAT resources, click the link below!

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MCAT Enzymes Features

Here are some key enzyme features:

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Cofactors and Coenzymes

Their purpose is to improve enzymatic function.

Cofactors: inorganic molecules, metals ions (Zn+2, Cu+2, Fe3+)

Coenzymes: small, organic, vitamin derivatives (NAD+, FAD, coenzyme A)


  • Apoenzymes
  • Holoenzymes
  • Prosthetic groups

Six Enzyme Classifications

Here’s a breakdown of enzyme classification:

Enzyme Activity, Enzyme Kinetics, and Enzyme Regulation

Enzyme kinetics MCAT content can feel a little daunting, so we’ve broken down how activity, kinetics, and regulation are all related below:

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Enzyme Regulation: Reversible Inhibition

Competitive Noncompetitive Mixed Uncompetitive
Binding Site Active site Allosteric site Allosteric site Allosteric site
Impact on Km Increases Unchanged Increases or decreases Decreases
Impact on Km Unchanged Decreases Decreases Decreases

A Final Word on MCAT Enzymes Questions

Enzyme content can feel overwhelming as you’re studying, but the key to understanding their more complex activity and regulation lies in first grasping their features and functions. And when you understand the mechanics of enzyme kinetics, you’ll be better able to memorize the Michaelis–Menten equation. Remember, succeeding on this section requires more than just formula memorization.

Happy studying and good luck!


  • Kat Thomson

    Kat is the Senior Curriculum Manager at Magoosh with a specialty in the MCAT. She has a BA from the University of California, Santa Barbara, and a Ph.D. in medical sociology from the University of California, San Francisco, where she earned the Distinguished Dissertation Award in the Social and Behavioral Sciences. Kat has been teaching premed and nursing students since 2005 as a Visiting Assistant Professor at the University of San Francisco, Bowdoin, and the University of California, Berkeley, while collaborating on multiple research projects and publications. In addition to the MCAT, Kat has taught courses in Research Methods, Gender, Global and Environmental Health, and others. She is passionate about increasing the number of underrepresented minorities in medicine and helping students get into the medical schools of their dreams. You can join Kat on Instagram and YouTube.

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