1. Chemical Reactions & Enzymes
Chapter 6 section 2

2. Chemical Reactions
Anything your body does involves a chemical reaction
Healing a scab (making new cells)
Digestion (catabolism and anabolism)
Chemical equations
Reactants: starting substances (left side)
Products: substances formed (right side)
6CO2 + 6H2O  C6H12O6 + 6O2

3. Chemical Equations

4. Energy of Reactions
Activation Energy: the minimum amount of energy needed to start a reaction
Types of reactions:
Exothermic (releases heat)
Energy of the products is lower than energy of the reactants
Endothermic (absorbs heat)
Energy of the products is higher than energy of the reactants

5. Exothermic Reactions

6. Endothermic Reactions

7. Enzymes
Catalyst: a substance that lowers the activation energy required to start a reaction
Does not increase the amt. of products produced
Does not get used up in a reaction
Enzymes: biological catalysts made of proteins

8. Activation energy and enzymes

9. How Enzymes Work
Enzymes are specifically designed to react with specific substances
Example: amylase is an enzyme that breaks down amylose (compound found in starch)
Substrate: the reactant that binds to the enzyme
Active Site: site on the enzyme where the substrate binds (lock and key design)
Enzyme-substrate complex:
The enzyme changes shape once the reactant bonds to it
Enzyme helps create and destroy bonds
Enzyme releases product

10. How Enzymes Work

11. Factors that affect EnzymespH
How acidic or basic a substance is
Each enzyme has an ideal pH range
1-6 (acidic)
8-14 (basic)
Temperature
Each enzyme has a temperature range in which it is most effective
High temperature can denature enzyme (break it apart)
Low temperatures can slow down enzyme activity
Example:
Enzymes in humans work best at 98.6° F (37° C)
Enzymes in bacteria can work well under much higher temp.