Enzyme Kinetics Laboratory
Change substrate, enzyme, temperature, pH and inhibitors, and watch a live Michaelis-Menten curve - then switch to a Lineweaver-Burk plot to estimate Vmax and Km yourself.
Change substrate, enzyme, temperature, pH and an inhibitor, and watch the reaction-rate curve redraw live. Switch to the Lineweaver-Burk view to turn the curve into a straight line.
About the Enzyme Kinetics Laboratory
Free enzyme kinetics laboratory. Change substrate, enzyme, temperature, pH and inhibitors, and watch a live Michaelis-Menten curve - then switch to a Lineweaver-Burk plot to estimate Vmax and Km yourself. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for biology, the enzyme kinetics laboratory runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Change substrate, enzyme, temperature, pH and inhibitors, and watch a live Michaelis-Menten curve - then switch to a Lineweaver-Burk plot to estimate Vmax and Km yourself. Use it to explore biology ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Enzyme Kinetics Laboratory
- Use the controls to change Substrate concentration, Enzyme concentration, Temperature, pH, Inhibitor type, and more. The simulation reacts instantly.
- Pick an option such as None, Competitive, Noncompetitive, Michaelis-Menten to switch modes or load an example.
- Press "Check my estimate", "Load mystery inhibitor", "Submit answer", "Reset to defaults" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Push temperature past the enzyme's optimum and watch the rate collapse.
- Add a competitive inhibitor and watch Km rise on the curve.
- Switch to Lineweaver-Burk and estimate Vmax and Km from the intercepts, then check your answer.
- Compare competitive and noncompetitive inhibition at the same inhibitor concentration.
Key ideas you can learn
- The Michaelis-Menten equation v = Vmax[S] / (Km + [S]) describes how reaction rate depends on substrate concentration.
- Km is the substrate concentration where the reaction runs at half its maximum rate.
- A competitive inhibitor raises the apparent Km but leaves Vmax unchanged; a noncompetitive inhibitor lowers Vmax but leaves Km unchanged.
- A Lineweaver-Burk plot turns the curve into a straight line so Vmax and Km can be read from its intercepts.
Where this is used in the real world
Drug designers use exactly this kind of kinetics to test whether a new medicine competitively or noncompetitively blocks a disease-related enzyme.
Who is this simulation for?
Biology students and teachers who want to explore living systems, populations and genetics interactively and safely.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
What does Km actually mean?
It measures how much substrate is needed to reach half-maximal reaction rate - a small Km means the enzyme binds substrate tightly.
How can you tell competitive from noncompetitive inhibition from a graph?
On a Lineweaver-Burk plot, competitive inhibition changes the x-intercept (Km) but keeps the same y-intercept (Vmax); noncompetitive inhibition changes the y-intercept but keeps the same x-intercept.
Is the Enzyme Kinetics Laboratory free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Enzyme Kinetics Laboratory work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.