6 Marks Question (Copy)

✅ A.T.P. Format: Aim – Technique – Precision

A – Aim (What are you testing?)

• State clearly what the experiment is investigating.
• Mention both:
  • Independent variable (what you change)
  • Dependent variable (what you measure)

Example:
To investigate the effect of temperature on the rate of enzyme activity.

T – Technique (Method and Setup)

Break this into sub-parts:

1. List Apparatus

• Mention all equipment and materials:
  • Test tubes, stopwatch, beakers, thermometer, measuring cylinder, reagents, etc.

2. Step-by-Step Method

Use clear steps (preferably numbered or bullet points):

• Keep steps logical, short, and in sequence
• Include:
  • Accurate quantities (e.g., 5 cm³ starch solution)
  • Time intervals
  • How data is measured or recorded
  • Specific setup for the variable tested

Example:

1. Label 5 test tubes: 20°C, 30°C, 40°C, 50°C, 60°C
2. Add 5 cm³ starch + 1 cm³ amylase into each.
3. Place in water baths at assigned temperatures for 10 minutes.
4. Every 30 seconds, remove a drop and test with iodine.
5. Record time until no blue-black color appears.

3. Variables

P – Precision (Control, Repeat, Safety)

Control Setup

• Describe the control experiment
• Example: Boiled enzyme or setup without light

Repeat & Reliability

• Mention you will repeat the experiment and take an average for accuracy

Safety

• Include 1–2 safety precautions relevant to the setup
• Examples:
  • Wear goggles when using iodine or Biuret
  • Use tongs with hot water bath
  • Handle glassware carefully

✅ Template Answer (Full 6-Mark Structure)

Q: Plan an experiment to investigate how temperature affects enzyme activity.

1. Aim:
To investigate the effect of different temperatures on the time taken for amylase to break down starch.

2. Method and Apparatus:

• Apparatus: Test tubes, beakers, water baths at different temperatures, iodine, starch solution, amylase, stopwatch, spotting tile, thermometer
• Add 5 cm³ starch solution and 1 cm³ amylase into each test tube.
• Place tubes in water baths at 20°C, 30°C, 40°C, 50°C, and 60°C.
• Every 30 seconds, take a drop and test with iodine on a tile.
• Record the time when iodine no longer turns blue-black.

3. Variables:

• Independent: Temperature of water bath
• Dependent: Time for starch to be digested
• Controlled: Volume of solutions, pH, concentration, timing, source of enzyme

4. Control:
Use a boiled amylase solution to confirm no reaction happens without active enzyme.

5. Repeat:
Repeat each temperature setup 3 times and calculate average time.

6. Safety:
Wear goggles when handling iodine. Use care with hot water baths.

✅ Marking Breakdown