1. Chemical Reactions and Enzymes

2. 1. Reactants = the starting substances in a chemical reaction
2. Products = substances formed during the reaction
REACTANS  Products

3. Activation Energy
1. Activation Energy is the amount of energy needed for reactants to form products in a chemical reaction.

4. Speeding up Reactions
1. Slow reactions or reactions with high activation energies need a catalyst.
2. Catalyst = a substance that lowers the activation energy needed to start a chemical reaction.
3. Enzymes are biological catalysts.

5. Speeding up Reactions Characteristics of Catalysts/Enzymes:
Don’t increase the amount of product.
Can be reused.

6. Enzymes 1. Substrates are the reactants that bind to the enzyme.
2. An active site is the specific location where a substrate binds.

7. Enzymes
3. The substrates must fit exactly into the active site. This is called the lock and key model.
4. Enzymes can join or break substrates into products.

8. Enzymes 5. Enzymes work best at a certain pH and temperature.
6. Roles of Enzymes:
1) regulating chemical pathways
2) making materials
3) releasing energy
4) transferring info

9. Breaking 1 Substrate into 2 Products
G:\Teacher Resources\Downloaded Videos\Enzyme Action.avi

10. Joining 2 Substrates into 1 Product

11. Salivary Amylase: An enzyme in your body!