1. Chemical Reactions

5. Activation energy- minimum amount of energy needed for reactants to form products in a chemical reaction. Endothermic Reaction- absorbs heat energy Exothermic Reaction- releases energy in the form of heat.

6. Catalyst- substance that lowers the activation energy needed to start a chemical reaction. -It speeds up the reaction but does not increase how much product is made. It also does not get used up. Enzymes- special proteins that are biological cataylsts. Ex: Amylase found in saliva.

7. Substrates- reactants that bind to the enzyme. Active site- specific location where a substrate binds on an enzyme.