1. Enzymes
pp 35-37, 57

2. Chem Rxns Review Every reaction has reactants that yield products
Reactants  Products
Requires energy to start the reaction (activation energy, Ea)

3. Enzyme Properties All end in –ase i.e. synthase, polymerase, helicase
Enzymes are Proteins

4. Enzyme Properties Function: Reduces the activation energy (Ea)
w/o enzymes, chemical rxns in the body would occur too SLOWLY!

5. Enzyme Properties Each is specific to a reaction Reusable
Does not affect products
A + B + D  AB + D
Which letter represent the enzyme?

6. Enzyme Properties
Helps assemble the product OR disassemble the reactants
Changes shape when attached to the substrate (reactants) at active site

7. Lock and Key Model
The lock-and-key model helps illustrate how enzymes function.
substrates brought together
bonds in substrates weakened
Substrates bind to an enzyme at certain places called active sites.
The enzyme brings substrates together and weakens their bonds.
The catalyzed reaction forms a product that is released from the enzyme.

8. Factors that Affect Enzyme Activity
1. Temperature
Temp increase activity only to a certain point
Call this optimal temp
Activity decreases if it gets too cold or too hot
Enzymes denature if they get too hot

9. Factors that Affect Enzyme Activity
2. pH
Enzymes have a specific pH they can work within
Too low or too high and activity slows or even stops
Ex: Pepsin works best at a pH of 2

10. Factors that Affect Enzyme Activity
3. Concentration
The more enzyme, the faster the reaction rate
Point of saturation: enzymes can only work so fast even if you add more substrate
Max out on activity