Name _______________________________________
Biology Period ____
Chapter 5 Section 5
Enzymes
Objectives
Explain how enzymes affect activation energy.
Describe how an enzyme’s shape is important to its function.
Describe how a substrate interacts with an enzyme.
Enzymes
=specialized _________________ that coordinate a cell’s activities
In order for a chemical reaction to begin, bonds need to be weakened in the __________.
-reactants are the ____________ substances in a reaction
-____________________ are the ending substances in a reaction
This activation process requires that the molecules ___________________ energy
Activation Energy
=the start-up energy that ____________the reactants and __________a chemical reaction
Some ways to activate reactants:
1. _______________-destroy a cell
2. _______________-not easy to do in a cell
3. _______________-”cell-friendly”
Cells rely on ___________________________ to speed up a reaction (rxn)
The main catalysts of chemical reactions in organisms are specialized proteins called
_____________________
-enzymes provide a way for rxns to occur at the cell’s normal ____________________
*Doesn’t supply activation energy to the reacting molecules, but instead
________________ the energy requirements
Each enzyme catalyzes a _______________________ kind of reaction
How Enzymes Work
Why do enzymes catalyze only one type of reaction?

*the specific reactant acted upon by an enzyme is called its _____________________
*the region on the enzyme into which the substrate fits is called its __________________
-the fit between substrate and active site is not rigid like a lock and a key
-more like a hand in a glove
Mrs. Kerstetter
Name _______________________________________
Biology Period ____
-this positions the ______________________________ of the active site in an area
where it can catalyze a rxn
-most enzymes end in –ase
What type of reaction occurs as the water
molecule comes in and the substrate is
converted to products?
______________________________
Product of hydrolysis of sucrose by sucrase?
 ______________ and _______________
-the products are released, and the enzyme can now catalyze another sucrose molecule
Another way that enzymes can lower activation energy is by accepting ______________
reactant molecules into adjacent sites
Enzyme's _______________ and _____________________ are essential to its functions
*_______and __________________ affects how well or if an enzyme works at all
Mrs. Kerstetter