Purpose
Catalase is an enzyme found in living tissue. In this lab you will design a fair test, run trials at a virtual lab bench, record your own measurements, graph them, and use your evidence to support a claim about what affects how fast catalase works.
The reaction
The oxygen gas escapes as bubbles that pile up as a foam column above the liquid. You will measure the foam column with a ruler.
Safety (for the real lab)
- Wear splash goggles and an apron. Hydrogen peroxide can irritate eyes and skin; rinse with water right away.
- Wash hands after handling raw liver or chicken. Keep food and drink away from the bench.
- Hot-water baths can scald: use tongs or a holder for tubes.
- Never seal a tube that is producing gas.
This simulation runs entirely on your device. Your progress saves automatically in this browser, and you can also save it to a file to continue elsewhere.
Before the bench unlocks
To unlock the bench you need:
How to use the bench (mouse, touch, or keyboard)
- Drag items with a mouse or finger — or tap / press Enter on any item to open a menu of places to move it. Tab moves between items in the order you use them: tray, balance, cutting board, bottles, pipette, tube, ruler, then the bath dial and the rack.
- Follow the recipe card at the top of the bench, one tube at a time. Each step ticks itself when you do it, and the bench will tell you if something doesn’t match the recipe.
- Liver from the tray → balance (weigh; use the −/+ buttons to trim) → cutting board (whole / dice / puree) → test tube.
- Pipette → a stock bottle to draw 5 mL, then → the tube to dispense. The stopwatch starts by itself the moment the H₂O₂ goes in and stops by itself at the protocol time — there is nothing to click. Buffer bottles drop 1 mL of buffer into the tube. Tubes can be dragged into the water bath and back.
- Ruler: drag it beside a tube, or focus it and use the arrow keys (Shift = bigger steps). Line up its 0 mm with the surface of the liquid.
- Bath dial: drag the knob, use the − / + buttons, or focus it and press the arrow keys.
Data table
Graph
Your investigation
Variable you tested:
Your hypothesis:
Claim
A statement that answers the question you investigated.
Evidence
Specific measurements from your own data table.
Reasoning
Connect your evidence to your claim using science ideas.