Enzyme Inhibition Tournament
Eight MCAT rounds on inhibitor classes: active-site competition, fomepizole vs methanol, Lineweaver-Burk geometry, matching signatures, a Km_app calculation, irreversible vs reversible examples, and why uncompetitive lines stay parallel.
Where the Glucose metabolism (gluconeogenesis branch) fits in Metabolism of carbohydrates
PFK-1, hexokinase, and the gluconeogenic bypasses on this map are the MCAT's favorite regulated enzymes — and the template for how inhibitors move Km and Vmax. Click the highlighted glucose-metabolism panel to enter the tournament.
Click the highlighted Glucose metabolism (gluconeogenesis branch) box to continue.
What this tournament tests
Each task maps to a distinct MCAT cognitive demand. The first two orient you in the broader topology; the next 8 test the high-yield mechanism, regulation, sequence and quantitative reasoning that consistently appear on test day.
The Bigger Picture
Place regulated carbohydrate enzymes on the Reactome map.
Whole-Pathway Overview
Study the WikiPathways figure before the inhibitor items.
Fill in the Blank
Name the site a competitive inhibitor occupies.
Disruptor
Explain fomepizole in methanol poisoning.
Sequence Ordering
Walk a competitive inhibitor across a Lineweaver-Burk plot.
Match the Pairs
Pair each inhibitor class with its LB signature.
Numeric Input
Compute apparent Km when a competitive inhibitor triples Km.
Select All That Apply
Separate true inhibitor facts from common mix-ups.
Odd One Out
Pick the irreversible covalent inhibitor out of a competitive list.
Uncompetitive Disruptor
Why uncompetitive lines are parallel.
Public leaderboard
Your score posts to a global, persistent leaderboard scored by points first, time as tiebreaker.
Enzyme inhibition in 60 seconds
Competitive: binds free E at the active site. Vmax unchanged, Km up. Lines meet on the y-axis. Outcompeted by saturating [S].
Pure noncompetitive: binds E and ES equally at another site. Km unchanged, Vmax down. Lines meet on the x-axis.
Uncompetitive: binds only ES. Km and Vmax both fall; slope unchanged; parallel lines. Irreversible inhibitors (aspirin, nerve agents) destroy [E] and cannot be diluted out.
FAQ
Can you tell inhibitor type from a single velocity?
No. You need a plot — ideally Lineweaver-Burk or a pair of Michaelis-Menten curves ± inhibitor — so you can see whether Vmax, Km, or both moved.
Why does ethanol also treat methanol poisoning?
Ethanol is a competing substrate for ADH, not a classic dead-end inhibitor. It occupies the active site so methanol is not oxidized. Fomepizole is cleaner because it is a true competitive inhibitor with a very low Ki.
Is this a copy of the /study enzyme game?
No. /study/biology/enzyme-game is a different URL and a different question set. This page is the MCAT tournament on inhibitor geometry and clinical examples.
Do I need an account to play?
No. The tournament is fully public.
Keep going
Overview diagram: Reactome Pathway R-HSA-71387, licensed CC BY 4.0. Reference figure: WikiPathways WP534.