Download Exploration Activity: Enzymes

Exploration Activity: Enzymes
Research
Research the following information about enzymes.
 Definition of enzyme
 Definition of substrate
 Importance of enzymes
 How enzymes are named
 Where enzymes are made
 Basics of the Lock and Key model of enzyme action
 Basics of the Induced Fit model of enzyme action
 Active Sites
 Impact of changes in temperature and pH on enzymes
Modeling Enzyme Action
1. Design a 3-D model that illustrates both models of enzyme function. The model you design should demonstrate
both the Lock and Key and the Induced Fit explanations of enzyme interaction with substrate. Your model should
also be able to demonstrate the impact of changes in HEAT and/or pH on enzyme function.
2. Prepare a 2 to 3 minute oral presentation describing how your model demonstrates both possible explanations of
how enzymes interact with substrates and how heat and pH impact your enzyme’s function.
3. Present your model to the class. Be sure all members of the group are involved in the presentation and that you
clearly show your understanding of the difference between Lock and Key and Induced Fit models of enzyme
function. Your model and explanation must answer the question: “How can enzymes be so specific in terms of the
substrate they impact?”
Activity Summary Questions
Basic Graphs
Enzyme Efficiency
I)
Temperature
(a)
A)
B)
C)
D)
Temperature
(b)
Acid
Base
Acid
(c)
Base
(d)
Graph (a) shows that this enzyme will work best at what type of temperatures?
Graph (b) shows that this enzyme will work best at what type of temperatures?
Graph (c) shows that this enzyme will work best at what type of pH?
Graph (d) shows that this enzyme will work best at what type of pH?
Basic
Neutral
Acidic
II) Graph
A) At what pH does enzyme A work best at?
B) At what pH does enzyme B work best at?
C) How high was the enzyme efficiency for enzyme A at a pH of 8?
D) Which enzyme works best at a basic pH?
E) Which enzyme is the most efficient at any pH?
pH
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Enzyme A
Efficiency
10
30
55
75
90
85
70
60
35
20
0
0
0
0
0
Enzyme B
Efficiency
0
0
0
0
0
20
35
45
50
65
80
55
40
30
20
III. Evaluating Graphs
Below you’ll find graphs that show how pH affects four different enzymes. For each, explain the trend you see, and where
the enzyme is most efficient, shown by the optimum, or best pH.
I. Chymotrypsin (enzyme that digests proteins)::
II. Cholinesterase (enzyme that affects neurotransmitters):
III. Pepsin (enzyme that digests proteins):
IV. Papain (enzyme in papaya):
IV. Pulling it all together
Answer the following question based on the table below:
Enzyme
Effective Temperature (◦C)
Optimum pH
A
60-80
3
B
30-40
5
C
20-38
9
D
20-27
7
If enzyme C is functioning at 20 degrees Celsius and a pH of 7, under which conditions would the rate of
enzyme activity probably increase?
a)
The temperature is decreased to 22 degrees and the pH is kept the same.
b)
The temperature is increased to 30 degrees Celsius and the pH is increased to 8.
c)
The temperature is kept the same and the pH is decreased to 6.
d)
The temperature is increased to 44 degrees Celsius and the pH is kept the same.
Explain why: