DSE Biology: Enzymes and Metabolism

DSE Biology: Enzymes and Metabolism — Tutor Lesson Plan

2026-10-27

Tutor lesson-prep guides · Secondary biology

Students can recite that enzymes are biological catalysts but cannot draw the temperature curve. One experiment makes optimum and denaturation visible.

Objectives — the student can state three properties of enzymes, explain temperature and pH effects, and design an experiment with controlled variables.

01 Prerequisites (3-minute check)

If any of these fails, fix it before the lesson starts.

Skill	Quick check	Pass mark
Proteins	What are proteins made of?	Amino acids
Cells	Where do cell reactions happen?	Cytoplasm and organelles
Variables	Distinguish independent and controlled variables	Correctly

02 Lesson flow (60 minutes)

Time	Stage	Tutor does	Student does
0-8 min	What an enzyme is	Catalyst plus protein	State three properties
8-22 min	Lock and key	Substrate and active site	Draw and explain
22-38 min	Temperature and pH	Three-part curve	Explain each part
38-52 min	Experimental design	Variables and measurement	Design one
52-56 min	Wording	Use “active site is denatured”	Rewrite an answer
56-60 min	Exit check	Three questions marked	Finish alone

03 Teaching script (read it out)

Scene 1: A protein catalyst

Enzymes are proteins that speed up reactions without being used up.
Three properties: specificity, affected by temperature and pH, reusable.
Every answer names the enzyme, the substrate and the active site.

Student states one sentence per property.

Scene 2: The temperature curve has three parts

Low temperature: low activity but reversible. Optimum, about 37 degrees in humans: highest activity.
Too high: the active site changes shape and the enzyme is denatured, irreversibly.

Student draws and labels the three parts.

Scene 3: Experiments need controlled variables

Independent variable: temperature, for example 10, 20, 37 and 60 degrees.
Controlled: pH, substrate concentration, enzyme volume, time.
Measured: substrate used or product formed per unit time.

Warn: varying temperature alone is not a design.

04 Question types and worked steps

Type	Example	Steps	Answer
Properties	Why are enzymes specific?	Active site shape fits the substrate	Lock and key
Temperature	Why does activity fall after 60 degrees?	Active site denatured	Irreversible
pH	What happens away from the optimum pH?	Active site charge and shape change	Activity falls
Design	Test temperature effect	Independent, controlled, measured	All three stated

Sanity check (teach this): The falling part of the curve is denaturation, not death; use the exact term.

05 Independent practice (3 questions)

Question	Answer	What to watch
Optimum temperature in humans	About 37 degrees	Body temperature
Why is denaturation irreversible?	The active site is permanently changed	Correct term used
Three variable types to state	Independent, controlled, measured	All three

06 Common mistakes and what to say

Mistake	Student writes	Say this
Only “catalyst”	no mention of protein	Say it is a protein.
Denaturation as reversible	cooling restores activity	It is irreversible.
No controls	only temperature varies	List controlled variables.
Vague wording	the enzyme dies	The active site is denatured.

07 Homework (paper, section and question numbers)

Secondary biology chapter index — Use the three questions on this page

08 Exit check (last 5 minutes)

Question	Answer	Decision
Three properties of enzymes	Specific, affected by temperature and pH, reusable	All right: move to genetics
Optimum temperature	About 37 degrees	One wrong: re-teach the curve
Is denaturation reversible?	No	Two wrong: repeat scene 2

09 Tutor FAQ

Are practicals needed?

Yes; one run with amylase or catalase is enough.

Memorise the curve?

Understand the three parts rather than the numbers.

How does this link to metabolism?

Enzymes speed up metabolic reactions, the sum of cell chemistry.

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A TutorZone lesson-prep guide. Written by the TutorZone team; questions and lesson flow are original and are not taken from any school or publisher material.