Enzymes

What do enzymes act as?
A catalyst which lowers the activation energy.
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What is an enzyme?
An enzyme is a globular protein which acts as a catalyst to speed up a reaction by binding onto a specific substrate which lowers the activation energy.
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What is the structure of an enzyme?
They are globular and the active site is the region which is functional which is where the enzymes breaks down substrates which forms an enzyme substrate complex when they bind together.
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Why do enzymes only catalyse one reaction?
Because the active site of the enzyme is only specific to only 1 type of substrate.
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What is the induced fit model of enzyme action?
Where the active site isn't complimentary to the substrate so the shape of the active site changes to form an enzyme substrate complex. This then breaks the substrate up.
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Why does a rate of reaction increase up until the optimum temperature?
Because the enzymes would have more kinetic energy from the heat therefore more enzyme substrate complexes can be formed.
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At higher temperatures, why does the rate of reaction drop?
Because the enzymes would start to become denatured therefore, the bonds would start to break, changing the shape of the active site so less substrates can fit into an enzyme. This means that less ESC are formed, reducing the rate of reaction.
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How does pH affect and enzyme?
It changes the amino acids which would result in no more ESC being formed. Bonds can be broken so therefore it changes the shape of the active site.
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How does having a low concentration of enzymes affect the rate of reaction
If there is a low concentration, then there wouldn't be enough active sites for substrates to bind to. Therefore, this would reduce the rate of reaction.
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What is a competitive inhibitor?
Something which binds to the active site of the enzyme which prevents enzyme substrate complexes being formed.
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What is a non- competitive inhibitor?
Something which binds to a different region of an enzyme other than the active site.
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How does a competitive inhibitor stop the enzyme from working?
It has a similar shape to the substrate which then binds into the active site which blocks substrates entering it, preventing enzyme substrate complexes from being formed.
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What does a non- competitive inhibitor do?
It binds to another region onto the enzyme and causes it to change shape therefore, preventing enzyme substrate complexes from being formed.
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How would adding urea affect the rate of an enzyme controlled reaction?
It breaks down hydrogen bonds which holds the tertiary structure meaning the enzyme will start to denature and then no more ESC can be formed.
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Card 2

Front

What is an enzyme?

Back

An enzyme is a globular protein which acts as a catalyst to speed up a reaction by binding onto a specific substrate which lowers the activation energy.

Card 3

Front

What is the structure of an enzyme?

Back

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Card 4

Front

Why do enzymes only catalyse one reaction?

Back

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Card 5

Front

What is the induced fit model of enzyme action?

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