AQA Biology Enzymes Revision Notes

• 1Enzymes lower the activation energy required for reactions.
• 2Each enzyme has an active site that is specific to a particular substrate.
• 3Enzyme activity can be affected by temperature, pH, and substrate concentration.
• 4Enzymes can be denatured, losing their functional shape and activity.
• 5Enzymes often require cofactors or coenzymes to function effectively.

Enzymes are special proteins that help speed up chemical reactions in our bodies. They work by binding to specific molecules called substrates at their active sites. When conditions like temperature or pH change, enzymes can work better or worse, and if they get too hot or too acidic, they can stop working altogether. Some enzymes also need helpers called cofactors to do their job.