1. ENZYME NOTES

2. Chemical Reactions Chemical Reaction – process that changes one set of chemicals into another set of chemicals Reactants – elements or compounds that enter into a chemical reaction Products – elements or compounds produced by a chemical reaction Example: 2H 2 + O 2  2 H 2 O  Reactants Product

3. Chemical Reactions Chemical reactions always involve the breaking of bonds in reactants and the formation of new bonds in products Energy is released or absorbed whenever chemical bonds form or are broken

4. Enzymes Catalyst – substance that speeds up the rate of a chemical reaction Enzymes – proteins that act as biological catalysts (speed up chemical reactions that take place in cells) Enzymes help lower the activation energy of a chemical reaction (the energy needed to get a reaction started)

6. Enzymes The reactants of enzyme- catalyzed reactions are known as substrates Substrates bind to a site on the enzyme called the active site

7. SubstrateProducts Enzyme Active Site

8. Enzymes The fit between the active site and substrates is so precise that it is often compared to a lock & key