Photosynthesis & Limiting Factors
Move the lamp, change CO₂ and temperature and count the oxygen bubbles from a pond plant.
Drag the sun (or the lamp switch) to change the light, and set carbon dioxide, water and temperature. Watch photons hit the leaf, carbon dioxide enter through the stomata, water split inside the chloroplast, oxygen leave and glucose build up. The factor in shortest supply limits everything.
About the Photosynthesis & Limiting Factors
Free photosynthesis & limiting factors. Move the lamp, change CO₂ and temperature and count the oxygen bubbles from a pond plant. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for biology, the photosynthesis & limiting factors 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.
Move the lamp, change CO₂ and temperature and count the oxygen bubbles from a pond plant. 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 Photosynthesis & Limiting Factors
- Use the controls to change Light intensity, Carbon dioxide, Water supply, Temperature, Time of day, and more. The simulation reacts instantly.
- Pick an option such as Day, Night, White, Red to switch modes or load an example.
- Press "Reset totals" 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
- Move the lamp twice as far away and see the bubble rate.
- Raise the light until CO₂ becomes limiting.
- Try green light and explain the result.
Key ideas you can learn
- Photosynthesis turns light, water and CO₂ into glucose and oxygen.
- The factor in shortest supply limits the rate.
- Light intensity falls with the square of the distance.
- Enzymes work best at an optimum temperature.
Where this is used in the real world
Farmers use this to design greenhouses with the best light, CO₂ and temperature for their crops.
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 is a limiting factor?
The factor that is in shortest supply and so stops the rate from increasing, even if the other factors are increased.
Why does the rate fall at high temperature?
Enzymes are denatured, so photosynthesis slows down.
Is the Photosynthesis & Limiting Factors 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 Photosynthesis & Limiting Factors 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.