Year 10
AQA
Higher

Explaining effects of substrate concentration and temperature on enzyme rate

I can explain how and why the rate of an enzyme reaction is affected by substrate concentration and temperature.

Year 10
AQA
Higher

Explaining effects of substrate concentration and temperature on enzyme rate

I can explain how and why the rate of an enzyme reaction is affected by substrate concentration and temperature.

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Lesson details

Key learning points

  1. The rate of a reaction is the amount of change (e.g. substrate broken down or product made) per unit of time.
  2. Enzyme reaction rate increases as substrate concentration increases until an optimum when all active sites are full.
  3. Enzyme reaction rate increases with temperature due to more collisions, until an optimum when all active sites are full.
  4. Enzyme rate decreases as temperature increases above the optimum as bonds break and the active site becomes denatured.
  5. Interpretation of graphs showing effects of substrate concentration and temperature on enzyme reaction rate.

Common misconception

Enzymes die rather than denature.

The word denature is clearly introduced and a CfU explores the word die vs denature.

Keywords

  • Rate of reaction - A measure of how much change occurs per unit of time.

  • Concentration - A measure of the quantity of dissolved substance.

  • Optimum - The conditions where maximum rate of reaction occurs.

  • Bond - The attraction between atoms in a molecule.

  • Denatured - A permanent change in the shape of an enzyme which stops it from working.

Content guidance

  • Equipment requiring safe usage.

Supervision

Adult supervision recommended.

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

Video

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6 Questions

Q1.
What region on an enzyme does the substrate bind to?
An image in a quiz
substrate site
Correct answer: active site
complex site
enzyme substrate complex site
Q2.
Put the steps in order to show how an enzyme works.
1 - The substrate and enzyme collide.
2 - The substrate binds to the enzyme.
3 - An enzyme substrate complex forms.
4 - A chemical reaction takes place.
5 - The product(s) are released.
6 - The enzyme is free to catalyse another reaction.
Q3.
Enzymes the amount of activation energy needed for a reaction to take place.
An image in a quiz
Correct Answer: lower, reduce, decrease
Q4.
The shape of the active site is to the substrate.
Correct Answer: complementary, specific
Q5.
Which of the following are enzymes?
lactose
Correct answer: lactase
maltose
Correct answer: maltase
Correct answer: amylase
Q6.
What type of molecule are enzymes?
Correct answer: proteins
lipids
carbohydrates
amino acids

6 Questions

Q1.
Which part of an enzyme does the substrate need to collide with for a reaction to take place?
Correct Answer: active site, the active site
Q2.
What is the rate of reaction?
how much substrate has been used up
how much substrate has not been used up
how long it took for the reaction to finish
Correct answer: how much product is formed per unit of time
Q3.
Below are two graphs showing the rates of enzyme facilitated reactions. Match the graph to the factor affecting the rate of reaction.
An image in a quiz
Correct Answer:temperature,graph B

graph B

Correct Answer:concentration of substance,graph A

graph A

Q4.
Put these steps in order to show what happens as the temperature of an enzyme controlled reaction increases.
1 - As temperature increases, molecules move faster as they have more energy.
2 - The rate of reaction increases, to its optimum.
3 - The bonds holding the enzyme molecules together start to break.
4 - The enzyme's active site changes shape and the substrate no longer fits.
5 - The rate of reaction slows to zero as all the enzyme molecules become denatured.
Q5.
Where on the graph is the substrate concentration greater than the enzyme concentration?
An image in a quiz
X
Correct answer: Y
Q6.
Where on the graph could the enzyme concentration be greater than substrate concentration?
An image in a quiz
Correct answer: A
B
C