Enzymes

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What do ENZYMES do?
ENZYMES at as biological catalysts, increasing the metabolic rate (speed of reactions inside the body). Without ENZYMES, these reactions would take place very slowly at body temperature.
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What is the metabolism?
The metabolism is the sum of thousands of biochemical reactions taking place inside the body. One chain of these reactions is called a metabolic pathway.
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How do ENZYMES act as biological catalysts?
ENZYMES increase the metabolic rate by reducing the ACTIVATION ENERGY (the amount of energy needed to start the reaction).
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Explain why ENZYMES are proteins.
ENZYMES are proteins, as they are roughly spherical in shape (meaning that they are GLOBULAR PROTEINS). The structure and function of the ENZYMES is determined by the order of the amino acids.
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What do ENZYMES do (other than act as catalysts)?
ENZYMES are used in the digestive system for breaking down food into small molecules (each ENZYME breaks down a certain type of molecule in the food) and in DNA, where they are used to replicate DNA and build molecules.
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What is the ACTIVE SITE in an ENZYME?
The ACTIVE SITE of an ENZYME is where a complementary substrate molecule can attach itself to the ENZYME. The catalysed reaction occurs here.
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What happens once the ENZYME-substrate complex has been formed?
Once the ENZYME-substrate complex has been formed, the products are released and the reaction can start again with a new substrate.
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Why does an ENZYME only catalyse one specific reaction?
An ENZYME only catalyses one specific chemical reaction, because only the substrate molecule with the correct shape will fit into the ENZYMES ACTIVE SITE. If the shape of the ACTIVE SITE is changed, that will effect the ENZYMES ability to work well.
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How does temperature effect ENZYME activity?
As the temperature increases, the number of reactions will increase.
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What happens when an ENZYME is DENATURED?
When an ENZYME is DENATURED, the ACTIVE SITE changes shape, meaning that the substrate cannot fit into the ACTIVE SITE, and the ENZYME cannot catalyse the reactions.
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What happens if the temperature becomes too high?
However if the temperature becomes too high, the weak bonds holding the TERTIARY STRUCTURE together will break, meaning the shape of the active site will have changed. The ENZYME has DENATURED and will no-longer work.
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What effect does pH have on ENZYMES?
If the pH is too high or too low, then the ENZYMES will DENATURE. If it is too acidic, then the H+ ions will disrupt the weak chemical bonds, which DENATURES the ENZYME. If the pH is too alkaline, the OH- ions will disrupt the weak chemical bonds.
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Card 2

Front

What is the metabolism?

Back

The metabolism is the sum of thousands of biochemical reactions taking place inside the body. One chain of these reactions is called a metabolic pathway.

Card 3

Front

How do ENZYMES act as biological catalysts?

Back

Preview of the front of card 3

Card 4

Front

Explain why ENZYMES are proteins.

Back

Preview of the front of card 4

Card 5

Front

What do ENZYMES do (other than act as catalysts)?

Back

Preview of the front of card 5
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