1. Themes: Structure meets Function
Enzymes
Themes: Structure meets Function

2. Objectives
How does the structure of an enzyme affect its function?

3. Chemical reactions in living things
Many important biological reactions (such as dehydration synthesis) happen very slowly.
The substrates (ingredients) have to be in the right position

4. Enzymes Catalysts: Speed up reactions They align substrates correctly
Shape is important!

5. How do enzymes work?

6. On the previous slide, be able to label:
Enzyme (catalyst): Speeds up reaction
Substrate: Material the enzyme is changing. (what you start with)
Products: what you end with
Active site: Portion of the enzyme that is interacting with the substrate.

7. Structure Meets Function
Enzymes have a very specific shape.
An enzyme cannot act on a substrate unless it fits like a “lock and key”

8. 4 levels of structure Primary: sequence of amino acids
Secondary: folding caused by H-bonding
Tertiary: folding caused by ionic, hydrophobic, or disulfide bonds
Quaternary: multiple subunits

9. 4 levels of structure

10. Homeostasis of Enzymes
What four factors affect enzyme activity: pH
Temperature
Enzyme Concentration
Substrate Concentration

11. Denatured Protein
Denaturation: When environmental conditions change the structure of the enzyme so that it can NO longer function (ever again!!!)

12. What affects how enzymes work?

13. Enzyme inhibitors
Competitive inhibition: another molecule competes for the active site.
Allosteric inhibition: something binds to the enzyme and changes the shape of the active site.