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Grade 12 · Biology

Enzymes & the active site

Why it matters

How enzymes lower activation energy.

Advanced20m readingPrerequisite: None

How do enzymes work?

Short answer

Enzymes are biological catalysts, usually proteins, that speed up reactions by lowering the activation energy needed for them to proceed. A substrate binds to a specific region called the active site, forming an enzyme–substrate complex that stabilizes the transition state. The enzyme is not consumed, so it can catalyze the same reaction again and again.

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Related topics

Frequently asked questions

What is the active site?
The specific region of an enzyme, shaped to fit a particular substrate, where the catalyzed reaction takes place.
Are enzymes used up in a reaction?
No. Like all catalysts, enzymes are regenerated unchanged and can catalyze many reaction cycles.