Investigating temperature and pH on amylase or catalase, and nutrition surveys linked to diet-related disease.
4 narrated scenes. Press play, listen and read along — the points appear as they are explained. Use ‹ Prev / Next › or the scene bar to jump to any scene.
The syllabus names two enzymes you may investigate: amylase and catalase. Here are both, done properly.
Narration uses your device’s built-in voice. No sound? Switch to “Captions only” — the captions advance on their own.
Copy these into your notebook in your own words — that is how they stick.
Starch disappears → iodine stays orange-brown; time to disappear measures rate.
≈ 37 °C for human enzymes; denatured by high temperature; each enzyme has an optimum pH.
H₂O₂ → water + O₂; measure foam height or gas volume.
Boiled enzyme; same volumes, concentrations, times; water baths/buffers.
Goggles with H₂O₂; care with hot water baths.
The kind of support a teacher gives after the lesson: worked examples to attempt first, a board illustration, key terms, common misconceptions and memory aids.
| Temperature (°C) | 20 | 30 | 40 | 50 |
|---|---|---|---|---|
| Time (s) | 240 | 120 | 60 | 200 |
Try it in your notebook first, then reveal the solution one step at a time.
Try it in your notebook first, then reveal the solution one step at a time.
| Experiment | Control | What it shows |
|---|---|---|
| Amylase and starch | Boiled amylase, or water instead of amylase | Starch disappears only because of the enzyme |
| Catalase in potato | Boiled potato | Foam is caused by the enzyme |
| Effect of temperature | Same volumes, concentrations and pH at every temperature | Only temperature changes |
A good control changes only one thing: it removes the active enzyme.
Enzyme graph: “up, peak, crash” — rate rises with temperature, peaks at the optimum, then crashes as the enzyme denatures.
Washing powders contain enzymes (proteases, lipases) chosen to work at low temperatures, so clothes are cleaned without boiling water — saving energy.
Drop a small piece of raw potato and a piece of boiled potato into separate cups of hydrogen peroxide (3%, from a pharmacy, with an adult). Compare the bubbles.
3 quick games on this lesson. Earn XP and badges as you play — your best score for each game is saved. Games are for practice and do not change your exam readiness.
6 items modelled on real CSEC Paper 1 questions. Choose one answer for each, then check. Aim for 80% or better.
Write full answers, then reveal the mark scheme and tick the points you earned (9 marks in total). Your answers are saved on this device.
Question 1 [9 marks]
Plan an investigation into the effect of temperature on amylase.
(a) Describe the method, naming variables and the control. [6]
(b) Predict and explain the results. [3]
Everything in this lesson is based on these parts of the CXC syllabus and papers.