Energy canNOT be created, nor destroyed, it can only change form.

The rate at which atoms or molecules move determines its state: * Particles tightly packed, move very slow. Particles loosely packed, move medium speed. Particles far apart, move very fast.

 Definition = a process that changes one set of chemicals into another set of chemicals.  Slow (ex. iron + oxygen leading to rust)  Fast (ex. H-gas plus oxygen leading to an explosion)

1. Reactants - shown on the left 2. Products – shown on the right CO 2 + H 2 O H 2 CO 3

 Activation Energy = the amount of energy needed to start a reaction.

Catalyst = lowers the amount of activation energy that is needed for a chemical reaction to begin. --

 Enzyme = a catalyst in living things that does not get changed by a reaction. It is made of protein.  Hint: Enzymes generally end in -ase (Ligase, primase, lactase)

 Enzymes are made of proteins.  They help speed up reactions and are UNCHANGED by the reaction.  If the shape of the enzyme changes it will NO LONGER WORK. Image from:

 When a proteins shape is changed, we call it denatured  Its not how you would naturally find it  Scrambled eggs…. Can’t go back  What can denature a protein?  Change in temperature (too hot, too cold)  Change in pH

Enzyme Demonstration… Enzymes are proteins…. What happens to a protein when you cook it? What happens when you change the pH?

2. EndergonicReactions = absorption of energy

Exergonic reaction: Products have less energy in bonds then the reactants Where does the energy go? Released as heat, light, or electricity Examples: Glow sticks, Hot hands (Exothermic)

Endergonic reaction: Products have more energy in bonds then the reactants Energy is absorbed! Ex: Instant ice packs

Click Image Video found at: