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

CO2 + H2O H2CO3

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)

Special note on Enzymes 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: http://www.cas.muohio.edu/~wilsonkg/old/gene2005/syllabus_F03_23.jpg

DENATURED PROTEINS 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 . E n d e r g o n i c Re a c t i o n s =a b s o r p t i o n o f e n e r g y

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

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

Animation: Summary of AE, Catalysts, and enzymes

Click Image

Video found at: http://www.sumanasinc.com/webcontent/animations/content/enzymes/enzymes.html