New
New
Year 10
AQA
Foundation

Effects of substrate concentration and temperature on rate of enzyme activity

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

New
New
Year 10
AQA
Foundation

Effects of substrate concentration and temperature on rate of enzyme activity

I can explain how 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 reaction rate decreases as temperature increases above the optimum, as 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.

  • 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 type of molecule are enzymes?
Correct answer: proteins
lipids
carbohydrates
amino acids
Q2.
True or false? Enzymes can affect the rate of a reaction.
Correct answer: True
False
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.
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
Q5.
What can be said about the shape of the active site and the substrate shape?
they are the same
Correct answer: they are complementary
the substrate is like a lock and the enzyme is like a key
Q6.
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

6 Questions

Q1.
True or false? The concentration of substrate will affect the rate of reaction.
Correct answer: True
False
Q2.
At high temperatures the shape of the enzyme's active site can change, and it no longer fits the substrate. We say the enzyme has become ...
Correct answer: denatured
energised
unbonded
denaturalised
Q3.
Match the labels to what is happening.
An image in a quiz
Correct Answer:a- At low temperatures,there are fewer successful collisions so the reaction rate is lower.

there are fewer successful collisions so the reaction rate is lower.

Correct Answer:b- At the optimum temperature,all active sites are full and reaction rate is as high as it can be.

all active sites are full and reaction rate is as high as it can be.

Correct Answer:c- At high tmeperatures,the enzyme is denatured. The reaction cannot be catalysed.

the enzyme is denatured. The reaction cannot be catalysed.

Q4.
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
Q5.
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
Q6.
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 substrate,Graph A

Graph A