How do enzymes work?

A-Level: Chemistry

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Enzymes are proteins, which themselves are long chains
(polymers) of amino acids. These amino acids tangle themselves
up into a ball shape, and hence most enzymes are globular
proteins. The tangling is not random but is dependent on the
nature of the amino acids that make up the protein, and how
they interact with one another.
There are many hundreds of different enzymes, and each enzyme
is specific for the substrate on which it acts. The substrate
is the substance that is present at the beginning of the
reaction. The substance which is made by the enzyme is called
the product. For example, the digestive enzyme amylase, which
is found in saliva, acts on the substrate starch to make
glucose.
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