Enzyme Experiment & Industry

Curriculum Area & Learning Level

Scottish Curriculum for Excellence – S3 (Second Year BGE)
Level: Third/Fourth Level – SCN 4-13b
"I can describe the properties and uses of enzymes to describe their wider impact on the world and evaluate their use in industry."

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Lesson Objectives

By the end of this 50-minute lesson, students will:

1. Understand that pectinase is derived from microbes and is used commercially to extract juice from fruit.
2. Plan and conduct an experiment to investigate how pectinase affects juice extraction from apple pulp.
3. Analyse and present results using a bar graph.
4. Develop scientific writing skills by producing a formal experiment write-up.
5. Engage in peer assessment by reviewing examples of good and bad practical reports.

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Lesson Structure (50 Minutes)

Starter Activity (5 Minutes)

• Pose the question: “How do we extract juice from fruit?”
• Brief discussion about commercial juice production, leading into the role of enzymes like pectinase.
• Introduce key scientific terms briefly: Enzyme, Substrate, Reaction, Control Variable.
• Explain pectinase comes from microbes and is used to break down the plant cell walls to release juice.

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Main Activity – Practical Investigation (35 Minutes)

Planning the Experiment (5 Minutes)

• Ask students to design their own experiment using the provided equipment.
• Guide them to ensure their only changing variable is presence or absence of pectinase.
• Support struggling groups with a photocopied setup diagram if required.
• Encourage students to write a hypothesis (e.g., "Pectinase will extract more juice from apple pulp than water alone.")
• Teacher approval before proceeding.

Conducting the Practical (20 Minutes)

• Students set up their apparatus as follows:
  • Add apple pulp to a filter paper-lined funnel.
  • Add either pectinase or water in separate experiments.
  • Allow to sit for 20 minutes while juice collects in measuring cylinders.
• While waiting, students begin writing their experiment report under four sections:
  • Aim
  • Method
  • Results (table layout prepared)
  • Conclusion (to be completed after measuring juice volume)

Data Collection (5 Minutes)

• Students measure and record the volume (ml) of juice extracted from both test setups.
• Construct a bar graph comparing results (pectinase vs water).
• Discuss results - Did pectinase work? Why?

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Plenary & Peer Assessment (10 Minutes)

• Pair discussion: What makes a well-written experiment report?
• Provide laminated copies of good and bad experiment reports for comparison.
• Students self-assess their own write-ups and suggest at least one improvement.
• Quick-fire quiz:
  • What is pectinase used for?
  • Why do enzymes improve industrial processes?
  • What was our independent variable?

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Resources & Equipment

Per Group of Two Students (for a class of 20)

✔ Apple pulp samples
✔ Filter funnels + Filter paper
✔ 10ml Pectinase solution (not pre-measured)
✔ 10ml Water solution (control, not pre-measured)
✔ 10ml syringes x 10
✔ 100ml Beakers x 10
✔ Plastic teaspoons x 10
✔ 25ml Measuring Cylinders x 10
✔ Learning Support ‘Help Sheet’ on planning an investigation

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Extension Task (For Early Finishers)

• Research different industrial uses of enzymes (e.g., biological detergents, cheese production).
• Write a short paragraph comparing pectinase and another industrial enzyme.

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Assessment Strategies

✅ Formative Assessment: Observing student discussions & experiment setup.
✅ Peer Assessment: Comparing good and bad experiment write-ups.
✅ Summative Assessment: Reviewing experiment write-ups and graphs to measure understanding.

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Teacher Notes & Differentiation

• Provide visual prompts for students who struggle with setting up experiments.
• Offer a structured sentence starter for students needing writing support.
• Higher-ability students can be challenged to calculate the % increase in juice yield with pectinase.
• Ensure all students contribute by assigning roles (e.g., experiment leader, equipment manager, recorder).

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Final Thought for Students

"Enzymes power industries in ways we rarely notice – from cleaning clothes to making fruit juice. Imagine what future enzyme-based innovations could change our world!"

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End of Lesson