1. Apple Experiment Get a slice of apple and a slice of lemon.
When you get back to your seat:
1. Take a bite of one side of your apple.
2. Immediately squeeze lemon juice over the apple flesh that is now exposed from the bite.
3. IMPORTANT! Don’t get lemon juice all over the apple. Make sure that it is ONLY on the area that you just bit!
4. Set the lemon aside and wipe any lemon juice off of your hands with a napkin.
5. Take another bite from the opposite side of your apple slice.
6. Set your apple aside.

2. What Are Enzymes?
Enzymes are __________ (tertiary and quaternary structures).
An enzyme is a _________ in cellular reactions.
A catalyst accelerates a reaction.
Proteins, catalyst

3. Enzymes Are ________ for what they will catalyze Are _________
End in -_____
-Sucrase
-Lactase
-Maltase
Specific, reusable, -ase

4. How do enzymes work?
Each enzyme has a unique 3-D shape, including a surface groove called an ______ _____.
The enzyme works by binding a specific chemical reactant (_________) to its active site, causing the substrate to become unstable and react.
The resulting __________ is then released from the active site.
Active site, substrate, product

5. How Do Enzymes Work?
Enzymes work by _______ ______ which ________ activation energy.
Weakening bonds, lowers

6. Enzyme-Substrate Complex
The substance (reactant) an enzyme acts on is the _________.
Enzyme
Joins
Substrate
substrate

7. ______ _____ Enzyme Active Site Substrate
A specific region of an enzyme molecule which binds to the substrate.
Active Site
Enzyme
Substrate
Active site

8. Shape of a Protein …A job well done
An enzyme fits with its substrate like a ____ and ____.
Key and lock

9. EnzymeAnimation : Gary E. Kaiser http://student. ccbcmd
EnzymeAnimation : Gary E. Kaiser View :

10. Enzymes are ____ ________ in the reactions they catalyze
Enzymes are ____ ________ in the reactions they catalyze. Think of them as tiny machines in manufacturing. The more machines, the faster you get more _________.
Not consumed, product
Image:
Wine Bottling :
Wine Vats:

11. Review: 4 levels of Protein Structure

12. How Do You Stop an Enzyme?
_______________
• Changing of protein shape through some form of external stress
• A denatured protein can’t carry out its function because it is a different shape!
denaturation

13. Factors Affecting Enzyme Activity
Temperature pH
Cofactors & Coenzymes
Inhibitors

14. Temperature & pH
Think about what kind of cell or organism an enzyme may work in…
Temperatures far above the normal range _________ enzymes (This is why very high fevers are so dangerous. They can “cook” the body’s proteins)
Most enzymes work best near __________ pH (6 to 8).
Denature, neutral

15. Coenzymes & Cofactors
Non-protein substances (zinc, iron, copper, vitamins) are sometimes needed for proper enzymatic activity.
• Coenzyme versus Cofactor: What’s the difference?
_________ more general term. Includes inorganic and organic molecules.
_________ type of Cofactor, But specifically organic molecules.
Cofactor, Coenzyme
Image:
EnzymeCofactor : Public domain Wiki, Ribbon-diagram showing carbonic anhydrase II. The grey sphere is the zinc cofactor in the active site.

16. Coenzyme : Vitamin B12 Example:
Most _________ are coenzymes essential in helping move atoms between molecules in the formation of carbohydrates, fats, and proteins.
• Exclusively synthesized by ___________ (found primarily in meat, eggs and dairy products).
Vitamins, bacteria
Image: VitaminB12 : NIH, Public Domain

17. Two Types of Enzyme Inhibitors
1. ___________ ____________:
Chemicals that resemble an enzyme’s normal substrate and compete with it for the active site.
Enzyme
Competitive inhibitors
Substrate
Competitive inhibitor

18. 1. Competitive inhibitors:
Resemble an enzyme’s normal substrate and compete with it for the active site.
Image: Competitive Inhibition : www-biol.paisley.ac.uk/.../chapter3_2.html

19. Two Types of Enzyme Inhibitors
_______________ ______________:
Do not enter the active site, but bind to another part of the enzyme causing the enzyme to change its shape, altering the active site.
Enzyme
Non-competitive inhibitors
Noncompetitive
Inhibitor
Substrate
active site
altered

20. Enzyme Inhibitors
Blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance.
Many _____ are enzyme inhibitors.
Enzymes are also used as _________ and __________.
Drugs, pesticides, herbicides
Images
Dead Bug :
Prescription Drugs :

21. Featured Enzyme: Catecholase & Noncompetetive Inhibition
_________ juice and other acids are
used to preserve color in fruit,
particularly apples, by lowering the ____
and removing the copper site (cofactor)
necessary for the enzyme to function.
catecholase
catechol O  polyphenol
colorless substrate brown product
Lemon, pH