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Home > Biology > Revision videos > Enzymes




Enzymes are biological catalysts that speed up chemical reactions in the body. This video shows a demonstration of how an enzyme in the liver breaks down a dangerous substance into two harmless ones.

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Key learning points:

  • There are many thousands of chemical reactions going on inside our bodies.
  • Catalysts speed up chemical reactions without being used up or changed.
  • Enzymes are biological catalysts.
  • Catalase is the enzyme which breaks down harmful hydrogen peroxide into the harmless products, water and oxygen.
  • The active site of the enzyme is where the substrate molecule fits exactly and is broken down by the enzyme.

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