Eduqas A Level Biology
Eduqas A Level Biology 1.4 Enzymes Exam Questions
Free Eduqas A Level Biology exam questions on 1.4 Enzymes, with mark schemes. Covers enzyme action, factors affecting rate, inhibition and immobilised enzymes.
1.4 Enzymes exam questions
1 question pack of real past exam questions with its mark scheme. Answer every question without notes, then mark your answers line by line against the mark scheme.
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A Level Biology Flashcards
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Pick your exam board, then test yourself with the questions on this page.
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About Eduqas A Level Biology 1.4 Enzymes
This topic explains how enzymes work and what affects them. Expect graphs of rate against conditions and inhibition questions.
What you need to know
- Enzyme action Lock and key and induced fit models; enzymes lower activation energy.
- Factors affecting rate Temperature, pH, substrate and enzyme concentration.
- Inhibition Competitive inhibitors bind to the active site; non-competitive inhibitors bind elsewhere and change its shape.
- Immobilised enzymes Fixed to a support so they can be reused and products are not contaminated.
Common mistakes in 1.4 Enzymes
- Saying enzymes are killed by heat.
- Confusing competitive and non-competitive inhibition.
- Forgetting that adding more substrate overcomes competitive inhibition.
Try three 1.4 Enzymes exam-style questions
1. Explain how a competitive inhibitor reduces enzyme activity. (2 marks)
Show the mark scheme answer
It has a similar shape to the substrate and binds to the active site (1), so fewer enzyme-substrate complexes form (1).
2. Explain why increasing substrate concentration eventually has no effect on rate. (2 marks)
Show the mark scheme answer
All active sites become occupied (1), so enzyme concentration becomes the limiting factor (1).
3. Give one advantage of immobilised enzymes. (1 mark)
Show the mark scheme answer
Any one: can be reused, product not contaminated, more stable at high temperatures.
1.4 Enzymes FAQs
What does the Enzymes topic cover?
How enzymes work, factors affecting activity, inhibition and immobilised enzymes.
Which practicals link here?
Investigating the effect of temperature or substrate concentration on enzyme activity.
What is induced fit?
The active site changes shape slightly as the substrate binds, forming a closer fit.
Revise this topic with flashcards: A Level Biology Flashcards, with mark scheme answers for Anki and Quizlet.
