Lesson Enzyme
26.09.2024
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ENZYME
Enzymes as Biological Catalysts
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Enzymes are proteins that act as biological catalysts to speed up the rate of a chemical reaction without being changed or used up in the reaction
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They are biological because they are made in living cells
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Enzymes are necessary to all living organisms as they maintain reaction speeds of all metabolic reactions at a rate that can sustain life
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For example, if we did not produce digestive enzymes, it would take around 2 - 3 weeks to digest one meal; with enzymes, it takes around 4 hours
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Often the products of one reaction are the reactants for another (and so on)
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Factors Affecting Enzyme Action: Temperature
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Enzymes are proteins and have a specific shape, determined by the amino acids that make the enzyme and held in place by bonds
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This is extremely important around the active site as the specific shape is what ensures the substrate will fit into the active site and enable the reaction to proceed
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Enzymes work fastest at their ‘optimum temperature’
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In the human body, the optimum temperature is 37⁰C
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pH
Effects of pH
Changes in pH also alter the shape of an enzyme’s active site. Each enzyme work bests at a specific pH value. The optimum pH for an enzyme depends on where it normally works. For example, enzymes in the small intestine have an optimum pH of about 7.5, but stomach enzymes have an optimum pH of about 2.