1. Enzymes

2. Chemical Reactions
Reactants
Products
Change substances into different ones by breaking and forming chemical bonds
Reactants are the substances changed during a chemical reaction.
Products are the substances made by a chemical reaction
Activation Energy: amount of energy needed to start a reaction

3. How Do Enzymes Help?
Enzymes reduce energy needed (activation energy) to start a chemical reaction and increase reaction rate
Activation energy usually comes from an increase in temp
Slow process
Catalyst: substance that decreases the activation energy needed to start a chemical reaction
Speeds up reaction

4. Controlled Settings Human body ~98.6°F
Can’t raise body temp to start reactions
Internal reactions would be too slow to sustain life without a catalyst
Ex: Saliva
Breaks down starch 1,000,000x faster with amylase

5. Enzyme Structure
Enzyme shape allows specific reactants to bind together
Reactants = Substrate
Ex: Amylase & starch: Starch is the substrate because it binds to amylase
Substrates binds to activation sites on the enzyme (key fitting into a lock)
Once bonded to enzyme, substrates bonds weakened
Substrates bonds break
Substrates re-bond to each other
New product is formed

6. Another Enzyme Structure

7. Review 1) How do enzymes speed up chemical reactions?
2) What are the molecules called that react with enzymes?
3) Given the following chemical formula list the products and reactants: 6O2 + C6H12O6  6CO2 + 6H2O
4) What are the substances that are changed during a chemical reaction called?
5) What is another term for a catalyst?
6) Why can’t the human body raise its temperature to allow chemical reactions to happen quicker?
7) Given Amylase and Amylose, which is the substrate?
8) What do enzymes weaken between molecules?