1. Essential Question: How are actions of enzymes important to us?
Topic: ENZYMES
Essential Question: How are actions of enzymes important to us?
Objectives:
Explain how enzymes speed up the rate of biochemical reactions by lowering the reaction’s activation energy.
Identify and describe the effect of environmental factors on enzyme activity.

2. Chemical Reactions and Energy
Plant and animal cells break down sugars to get usable energy.
Cells build protein molecules by bonding amino acids together.
Lipids are broken down inside your body.
All of this requires energy!!!!
Energy is being added when chemical bonds are broken
Energy is being release when chemical bonds are formed.

3. Activation Energy
The amount of energy needed to get a reaction started.
Exo (out) thermic(heat) Reaction- releases more energy than it absorbs. The extra energy is release as light or heat.
Endo (in) thermic Reaction- absorbs more energy than it releases. Extra energy has to be absorb to make up the difference.

4. Exothermic vs Endothermic

5. Exothermic vs Endothermic

6. Enzymes are Catalysts
Catalyst- A substance that decreases the activation energy needed to start a chemical reaction, therefore speeding up the chemical reaction.
Amt. of activation energy decrease but time it takes for reaction increase.
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

7. Enzymes are Catalysts Enzymes are catalyst for living things.
Enzymes, which are a types of proteins(made of polypeptide chains), speed up chemical reactions.
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

8. Enzymes are used all over your body!
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

9. http://upload. wikimedia
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

10. Enzymes Structure
Each enzyme shape allows only certain reactants to bind to the enzyme.
The specific reactants that an enzyme acts on are called substrate.
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

11. Naming Enzymes
Take the name of the substrate the enzyme works on and add the suffix -ase
Example: Lactose  Lactase
Sucrose  Sucrase
Not always the case-some enzymes have the ending –in (pepsin)
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

12. Factors that affect enzyme activity
Temperature pH
Concentration

13. Enzymes and Temperature
Break up

14. What is the optimum temperature for this enzyme?
40◦C
30◦C
50◦C

15. Enzymes and pH

16. What is the optimal pH? 4 10 8

17. Which enzyme would you expect to show a higher activity at pH 7?
Fumarase
Arginase
Neither

18. Enzymes and Concentration

19. Enzymes and Concentration