1. Enzyme Action Lets speed things up

2. Catalysts Catalyst is a chemical that speeds up a reaction The catalyst never changes Never gets used up It lowers the activation energy needed for a reaction to take place Enzymes are organic catalysts

3. Enzymes Enzymes are organic catalysts Enzymes are made of proteins Proteins have a specific 3D shape This shape determines which reaction it speeds up. Only certain molecules will fit. Special shape is called an active zone The stuff that fits in there is called the substrate.

4. Here’s how it works Enzyme action Remember enzymes can break two molecules apart or put two molecules together. They don’t change they just speed things up. Every reaction in your body requires a different enzyme.

5. Activation energy

6. Peroxidase Peroxidase is an enzyme in liver and plant cells It breaks peroxide into water and oxygen 2  2H 2 O + O 2 Peroxide is the substrate Its made by cells as a waste product It’s toxic (it kills germs, dyes hair)