1. Enzymes Kathryn Blair, M.S. BIO 101 Core Concepts
May be used for educational purposes only

2. Basic Definitions
Metabolism: All chemical reactions in a cell Reactant: Start; change or combine Product: Result from reaction Catalyst: Speeds up reactions Enzyme: Catalyst body reactions

3. REACTANTS
PRODUCTS
CO2+ H2O H2CO3
(carbonic acid)

4. How does an enzyme work?
ENZYME has an ACTIVE SITE that SUBSTRATE (reactant) must perfectly fit into.
Enzyme: Lock; Substrate: Key

5. The Substrate must perfectly fit the Active Site of the Enzyme to work.

6. Enzymatic reactions are much faster
Enzymes are not used up in the reaction

7. It is like a discount on the cost of the reaction
Enzymes reduce the energy needed for reaction to occur (energy of activation)
It is like a discount on the cost of the reaction
100 50

8. Denaturing: extreme temperature and pH can change enzyme shape, rendering it useless.
NORMAL SHAPE
DENATURED SHAPE

9. Reaction Speed Affected by:
Temperature
Concentration pH
ACID 7
BASE

10. Temperature Effect on Enzymes
What does heat usually do to reactions?
Speed up
Cold?
Slow down
What temperature should human body enzymes work best at?
37o Celsius

11. pH Effect on Body Enzymes
Where would an enzyme that worked best in acidic conditions be located?
Stomach
Basic conditions?
Pancreas
Neutral conditions?
Blood and CSF (7.4), cytoplasm (7.2)