1. Enzymes: “Helper” Protein molecules

2. RECALL THE LEVELS OF PROTEIN STRUCTURE:
Primary
Structure
Secondary
Structure
Tertiary
Structure
Quaternary
Structure
Areas of coils and
pleated sheets due
to hydrogen bonding within a polypeptide
Eg. Hair
Overall shape of a polypeptide
Eg. Hormones
Shape of multiple polypeptides interacting together.
Eg. Enzymes
Amino Acid
Sequence of a
Polypeptide
An Enzyme is a functional PROTEIN in
Quaternary Structure.

3. Review of Chemical Reactions
A chemical reaction is the change of a substance into a new one that has a different chemical identity
Chemical
Reaction +
Reactants
The starting substances
Products
The ending substances

4. Chemical reactions of life
Processes of life
building molecules
synthesis
breaking down molecules
digestion + +

5. Nothing works without enzymes!
How important are enzymes?
Most chemical reactions in living organisms require enzymes to work
building molecules
synthesis enzymes
breaking down molecules
digestive enzymes
enzyme +
enzyme
We can’t live without enzymes! +
ENZYMES SPEED UP CHEMICAL REACTIONS

6. Enzymes are Protein Catalysts!
Catalyst: a substance that speeds up reactions without being used up.
They speed up chemical reactions by lowering the activation energy.
Activation energy: minimum amount of energy needed for a chemical reaction to occur.
Enzymes make it easier for reactions to occur.
Therefore, they will happen faster!

7. 2 Major Types of Enzymatic Reactions
synthesis
enzyme +
digestion
enzyme +

8. Enzymes are proteins
Each enzyme is the specific helper to a specific reaction
each enzyme needs to be the right shape for the job
enzymes are named for the reaction they help
sucrase breaks down sucrose
proteases break down proteins
lipases break down lipids
DNA polymerase builds DNA
Oh, I get it!
They end in -ase

9. Important Enzyme Vocabulary
Substrate: the substance that the enzyme acts on (the reactant).
Active site: the region of the enzyme where the substrate binds.
Enzyme-substrate complex: formed when a substrate is interacting with an enzyme.
The substrate and active site fit together like puzzle pieces.

10. Enzymes aren’t used up Enzymes are not changed by the reaction
used only temporarily
re-used again for the same reaction with other molecules
very little enzymes needed to help in many reactions
enzyme-substrate
complex
product
substrate
active site
enzyme

11. It’s the shape that matters!
Lock & Key model
shape of protein allows enzyme & substrate to fit
specific enzyme for each specific reaction

12. STEPS OF ENZYME ACTIVY…

13. 2 1 3

14. AMAZING SUMMARY VIDEO!! Watch & Answer the questions.
A substrate is something an enzyme can either _____________ up or ________________ down.
Enzymes are ___________________ (starts with “P”).
What are two things that affect enzymes?
______________________________
4) Denature means: _________________________________
5) People that can’t drink lactose are missing the enzyme called ___________________.

15. Chicken Liver & Hydrogen Peroxide Demo!
Chicken Liver contains the enzyme Catalase.
Catalase digests hydrogen peroxide, H2O2, into water and oxygen.
2 H2O2 ----> 2 H2O + O2
Substrate: ________________________
Enzyme: __________________________
Product(s): ________________________

16. SAMPLE 1
SAMPLE 2
SAMPLE 3
TEMPERATURE
(°C)
Freezing, Warm, or Hot?
OBSERVATION
Not many bubbles, some bubbles, many bubbles?
Based on your knowledge of denaturation, what do you think is happening to the enzymes?