1. Enzymes

2. What are Enzymes?
Enzymes are proteins that speed up chemical reactions.
They cause change, so they are also called catalysts.
Reactions can occur without enzymes, but they may take a really long time. Enzymes lower the amount of energy needed for the reaction to take place.

3. Enzyme Labeling

4. Enzyme Labeling 1. 2. 3.

5. What can enzymes do?
Some enzymes can break down substances into smaller parts.
Other enzymes can build substances that cells need.

6. There are thousands of enzymes!
Why?
Each enzyme is specific for one substrate (the substance it binds to).
The enzyme and substrate fit together like a lock and a key.
When the substrate and
enzyme bind, the enzyme
actually changes its shape
a little.

7. Enzymes are “green”!
Once an enzyme has finished with helping one reaction, it’s ready for another.
Enzymes are reusable.

8. Do enzymes always work?
NO - There are two factors that can denature enzymes, or alter the enzyme’s shape and stop it from doing its job. They are:
Temperature pH
(Denatured enzyme)

9. Has the enzyme been destroyed?
“Denatured” does not mean the enzyme has been destroyed. It has simply lost its shape.
Enzymes can be “renatured.” If they are returned to normal conditions, they will regain function.

10. When do enzymes work best?
Enzymes work best at an optimal temperature and pH level specific for that enzyme. Not all enzymes function at the same temp. or pH.
Amylase- enzyme in mouth
Pepsin- enzyme in stomach
Arginase- enzyme in intestines
Which ones work at the same pH?

11. How do you know it’s an enzyme?
Class
Function
1. Oxidoreductase
Catalyse redox reactions
2. Transferases
Catalyse transfer of a molecular group from one molecule to another
3. Hydrolases
Catalyse bond cleavage by the introduction of water
4. Lysases
Catalyse reactions involving the removal of a group to form a double bond or addition of a group to a double bond
5. Isomerases
Catalyse reactions involving intramolecular rearrangements
6. Ligases/Synthesases
Catalyse reactions joining together two molecules
What do all these enzyme names have in common?

12. More Enzyme Animations