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Enzymes: The Biological Catalysts That Make Life Fast Enough
- Enzymes are biological catalysts that speed up the rate of chemical reactions in living things.
- They are globular proteins, meaning their polypeptide chains fold into a rounded, three-dimensional shape.
- An enzyme is not used up or changed by the reaction it speeds up, so it can be used again and again.
Definition
Activation Energy
Activation energy is the minimum amount of energy required to start a chemical reaction.
Tip
- Because enzymes are reusable, a cell needs only tiny amounts of each one.
- A single enzyme molecule can catalyse the same reaction thousands of times per second.
How Catalysts Work: Lowering the Activation Energy
- Every reaction needs a starting push of energy called the activation energy.
