1. First Five Explain the meaning of the following terms: enzyme
substrate
product
active site
denatured

2. What are Enzymes?
Globular proteins that act as biological catalysts to increase reactions rates
Catalysts: substances that speed up reactions w/o being consumed
Biological? Because they are proteins; NOT because they are alive (they aren’t!)

3. Name: ________________________
1/08/2014
Enzymes: How they work
speed up biochemical reactions by lowering the activation energy of reactions that would normally happen anyway.
AS Bio: Enzymes Lesson 1

4. Mode of Action
Enzymes bind substrates (enzyme reactant) into active sites (pocket or groove on enzyme).
While the enzyme and the substrate are joined, the enzyme catalyzes the reaction and converts the substrate to the product(s).

5. Enzymes
A classic example of an enzymatic reaction is the hydrolysis of sucrose into glucose and fructose.

6. Enzymes
Another look…

7. Practice
Find the enzyme, substrate(s), and product(s) in the sentences.
I) Acetylcholinesterase breaks down acetylcholine into acetyl and choline.
Enzyme: ________________________
Substrates: ______________________
Products: _______________________
II) A disaccharide can be broken down into glucose and fructose by lysozyme

8. Practice
Find the enzyme, substrate(s), and product(s) in the sentences.
I) Acetylcholinesterase breaks down acetylcholine into acetyl and choline.
Enzyme: Acetylcholinesterase
Substrates: acetylcholine
Products: acetyl & choline
II) A disaccharide can be broken down into glucose and fructose by lysozyme
Enzyme: lysozyme
Substrates: sucrose
Products: glucose & fructose

9. Factors Affecting Enzyme Activity

10. Factors Affecting Enzyme Activity: Rate of Reaction vs Enzyme Concentration
Describe the activity of the enzyme as concentration of the enzyme increases.
Enzyme activity increases as enzyme concentration increases. Eventually enzyme activity plateaus even though enzyme concentration continues to increase.

11. Factors Affecting Enzyme Activity: Rate of Reaction vs. Temperature
Describe the activity of the enzyme as temperature increases.
Increasing heat energy causes more collisions between enzyme and substrate, until an optimal temperature is reached.
Above the optimal temperature, the enzyme denatures so the rate falls rapidly.

12. Factors Affecting Enzyme Activity: Rate of Reaction vs. pH
Describe the activity of the enzyme as pH increases.
Activity gradually increases up to the optimal pH and gradually decreases after the optimal pH.

13. Effects on Enzyme Activity
Rate of Enzyme Activity is influenced by:
Substrate concentration
more substrate = more activity until saturation
Amount of enzyme
more enzyme = more activity until saturation
Temperature
higher temperature = more activity until the enzyme’s protein denatures pH
usually in range of 6-8 for enzymes in humans
Inhibitors
reduce activity by binding or changing shape of active sites

14. Two types of inhibitors
Competitive Inhibitor
When something besides the substrate blocks the active site
Noncompetitive Inhibitor
When a molecule binds to another spot on the enzyme causing it to change shape and become inactive

15. Enzyme Simulation Rules: Only do your action upon your substrate.
The starting substrate and ending product must match the picture on your enzyme’s instructions.
If you can’t operate upon a particular substrate, move it on to another person or another table. 
Enzyme E is the last step in the process.  Although the description only shows two of the monomers stuck on the pencil, it will continue adding more and more until it is full.