1. Enzymes

2. What are Enzymes? Enzymes are proteins.
An enzyme is a catalyst. They speed up reactions that take place in your body.

3. What are Enzymes? Enzymes are very specific.
Will only catalyze one specific reaction.
Usually named for the reaction they catalyze.
They are reusable and not permanently changed.

4. How Do Enzymes Work?
Catalysts work by lowering the activation energy (the energy needed to start a chemical reaction) of the reaction=huge effect on the time it takes a reaction to happen!

6. Enzymes lower the activation energy!
Without Enzyme
With Enzyme
Free
Energy
Progress of the reaction
Reactants
Products
Free energy of activation

7. The Enzyme-Substrate Complex
Substrate: The substance (reactant) an enzyme works on.
Enzyme
Joins
Substrate

8. The Enzyme-Substrate Complex
ACTIVE SITE: The part of the enzyme where the substrate binds to it.
Active Site
Enzyme
Substrate

10. They fit together like puzzle pieces!

11. Video

12. The Enzyme-Substrate Complex
How does it work?
Substrates come in close physical contact at the active site.
Substrates bind together and are made into products.
The products are released and the cycle starts over.

15. How Enzymes are Named All enzymes end in –ASE!!
The enzyme often sounds like the substrate it breaks down.
SUBSTRATE
ENZYME
Lactose
Lactase
Maltose
Maltase
Sucrose
Sucrase
Lipids
Lipase
Cellulose
Cellulase
Polysaccharides
Amylase

16. Things that Regulate Enzymes
Temperature
High temperatures can change the structure of it. pH
Extremely high or low pH values can make it not work.

17. Review-Write these on the back of your notes.
Enzymes are
Lipids
Carbohydrates
Proteins
Nucleic Acids
Which binds to the active site of an enzyme?
water
product
another enzyme
substrate

18. Review (cont.)
An enzyme can only bind one reactant (substrate) at a time.
True
False
An enzyme speeds up a chemical reaction in the cell, but can only be used once.
True
False

19. Review (cont.)
Which substrate would this enzyme work on?

20. Review (cont.) Catalysts slow down a reaction. make enzymes.
speed up a reaction.
are nucleic acids.
What’s another name for enzyme substrate complex?
Fast and slow
Lock and key
Reactant and product
Apple and pear

21. Review (cont.)
Label:
Substrate
Active Site
Enzyme

22. Review (cont.)
What happens in a chemical reaction after the substrate binds to the enzyme at the active site?
The formation of a new product.
The formation of another enzyme.
Nothing happens.
The enzyme is damaged.