Starter quiz
- What are the monomers of proteins?
- lipids
- fatty acids and glycerol
- amino acids ✓
- glucose
- starch
-
Proteins are used in the body for ______ and repair in the body.- 'growth' ✓
- What is a catalyst?
- a substances that slows down chemical reactions
- a substances that stops chemical reactions
- a substances that speeds up chemical reactions ✓
-
Scientists use ______ as simpler representations of complex things and ideas.- 'models' ✓
- Where do consumers in food webs get the nitrogen they need to make proteins?
- air
- water
- soil
- food ✓
-
- True or false? Photosynthesis and respiration involve a series of chemical reactions.
- True ✓
- False
Exit quiz
- Match each keyword to its meaning.
- Catalyst⇔substance which speeds up the rate of a reaction without being used up ✓
- Substrate⇔substance which is acted upon by the enzyme ✓
- Enzyme⇔protein which acts as a biological catalyst ✓
- Active site⇔part of an enzyme where the substrate binds ✓
- True or false? All enzymes are proteins.
- True ✓
- False
- Put the following steps in order to describe how an enzyme works.
- 1⇔The substrate(s) binds to the active site.
- 2⇔An enzyme-substrate complex is formed.
- 3⇔The product(s) is released.
- 4⇔The enzyme can be re-used.
What part of the enzyme is A?- 'Active site' ✓
Who is correctly describing the effect of adding an enzyme on the activation energy of an enzyme controlled reaction?
Andeep: Enzymes increase the activation energy so the reaction happens faster.
Lucas: Enzymes lower the activation energy so the reaction happnes faster. ✓
- In the lock and key model of enzyme action, what is the lock?
- substrate
- enzyme ✓
- product(s)
-
Worksheet
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Lesson Details
Key learning points
- Enzymes are proteins that act as catalysts, speeding up chemical reactions.
- Without enzymes, many reactions would happen too slowly to support life.
- Enzymes catalyse reactions essential to life, including digestion and reactions in photosynthesis and respiration.
- Each enzyme has a 3D shape with an active site that a specific substrate fits into.
- The lock and key model to explain enzyme-substrate interactions.
Common misconception
That enzymes are used up in reactions, or that an enzyme can catalyse many different reactions.
Enzymes are not used up in the reactions that they catalyse, and that they can only catalyse one reaction, as explained by the lock and key hypothesis.
Keywords
Enzyme - A protein which acts as a biological catalyst.
Catalyst - A substance that speeds up the rate of a reaction without being used up.
Active site - The part of an enzyme where the substrate binds.
Substrate - The substance which is acted upon by the enzyme.
Model - Scientists use models as simpler representations of complex things and ideas.
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