First Five
Silently, answer the questions
below in your notebook.
Test Temp Original Final
Lipase is an enzyme that breaks
tube ( C)
color
color
down fats. We can use an indicator 1 0
Red
Red
to follow this reaction. The
2
10
Red
Orange
indicator is red to start with but 3 40 Red
Yellow
when all the fat has 4 60 Red
Orange
been broken down. Look at the
5
100 Red
Red
results table at the right.
1. What is the optimum temperature for lipase?
2. Why do you think the color didn’t change in test tube 1?
3. Why do you think the color didn’t change in test tube 5?
4. Predict what you think would happen if you warmed test
tubes 1 and 5 up to 40 oC. Explain your prediction.
o
Announcements
Quiz on Enzymes on
Monday/Tuesday
Factors Affecting Enzyme
Activity
Temperature
pH
Enzyme Concentration
Substrate Concentration
Factors Affecting
Enzyme Activity
 Rate of Enzyme Activity is influenced by:
Substrate concentration/amounts
(more substrate = more activity until
saturation)
Enzyme concentration/amounts
(more enzyme = more activity until all
of substrate is used up)
Factors Affecting
Enzyme Activity
 Rate of Enzyme Activity is influenced by:
Temperature (higher temperature =
more activity until the enzyme’s
protein denatures)
Factors Affecting
Enzyme Activity
Optimum
Temp
Factors Affecting
Enzyme Activity
 Rate of Enzyme Activity is influenced by:
pH (usually in range of 6-8 for humans,
unless in a basic or acidic part of the body)

Small intestine= basic
Acidic
Stomach
Stomach= acidic
Alkaline
Intestine
Enzymes are specific: Only one
shape of substrate works
Enzymes are reusable: Can be
used over and over again and is
not changed by a reaction
Enzymes can denature: Change
shape because of changes in
temperature or pH
Whiteboard
Write Enzymes
Practice
Problems
Whiteboard Write
Materials:
 Your Enzymes Practice
Problems Packet
 Your group
Instructions:
 As a group, discuss your answers to your
assigned problem(s)
 Write on the whiteboard your agreed-upon
solutions to the problem(s)
 Please include your question numbers/
letters
 Per group:
 Large whiteboard  Be sure that everyone has a chance to write
 Whiteboard marker
 Be prepared to share your solution to the class
 Eraser
 I will NOT correct errors or give answers at this
point
 When you present, the class will discuss its
correctness and make changes as needed
Whiteboard Write
Assigned Problems:
Groups
Question
Instructions:
 As a group, discuss your answers to your
assigned problem(s)
1
 Write on the whiteboard your agreed-upon
2
3
solutions to the problem(s)
 Please include your question numbers/
letters
4
 Be sure that everyone has a chance to write
1
 Be prepared to share your solution to the class
2
 I will NOT correct errors or give answers at this
3
4
point
 When you present, the class will discuss its
correctness and make changes as needed
Silently, answer the questions
below in your notebook.
1. Which of the following determines the function of an enzyme?
A mass
C shape
B charge
D weight
1. Name the parts of an
enzyme reaction
shown at right.
A
C
B
1. What would happen if the appropriate enzyme was added to a
reaction?
2. What would happen if the correct enzyme was placed in reaction
where the pH or the temperature was not optimal? Why?
Exit Ticket