1. Enzymes Part 1
Chapter 3

2. Click Me for a Movie!

3. ENZYMES!!! A special type of protein…???
In order for a protein to work at its SPECIFIC JOB, it must have….???
Because an enzyme is a protein, it MUST have….???
Can any key unlock the door to your house???
Can any substrate/reactant fit into a specific enzyme?
How many different enzymes do we have???

4. Proteins: Enzymes What is a chemical reaction?
Do they happen on their own?
If we stare at the piece of paper, are we going to be able to make the oxygen molecules in the air collide with the cellulose in the paper?
What do we need to do?
What are reactants?
What are products?

5. Proteins
Biological catalysts that speed up the rate of chemical reactions
They help make products faster!
Never used up!
“Matchmaker”
ENZYMES!!!

6. Enzymes Biological catalyst What is a catalyst?
Every metabolic rxn in organisms use enzymes
GLOBULAR PROTEINS
review levels of protein structure
Review characteristics of globular proteins
Always end in “-ASE”
Examples:
ATP synthase
Lactase
Sucrase
Amylase
Carbonic anhydrase
DNA polymerase
DNA helicase
RNA polyermase
DNA ligase
What is a catalyst?
Molecule that speeds up a chemical reaction
Remains unchanged at end of RXN

8. Anatomy of an Enzyme Globular Active site Enzyme-substrate complex
Hydrophilic R groups on the outside, hydrophobic R groups facing the interior of the enzyme
Active site
Region on enzyme where a specific molecule can bind (substrate)
Allows for perfect fit
SPECIFICITY
Active site of an enzyme it SPECIFIC for a particular substrate (molecule)
Enzyme-substrate complex
When substrate fits into the SPECIFIC active site of an enzyme and chemical reaction begins to occur
Combined structure of enzyme and substrate

9. Lock and Key Model vs. Induced Fit Hypothesis
Modified Lock and Key Model
1959
Same as lock and key EXCEPT…
ADDS the idea that enzyme and/or substrate can change shape slightly when substrate enters active site
Ensures PERFECT fit
Catalysis more efficient
Lock and Key Model
Original model for how an enzyme works
Substrate fits into active like a key in a lock
Enzyme (active site of enzyme) is specific for a particular substrate like a key is specific for a lock