Download 1.3 Enzymes supplemental work

Name: Standard: 1.3 - Explain the role of enzymes as catalysts that lower the activation energy of biochemical
reactions. Identify factors, such as pH and temperature that have an effect on enzymes.
Question 1: Sucrase speeds up the breakdown of sucrose into glucose and fructose. Sucrase is an example of which class or type of biological molecule? Question 2: Cellular respiration involves a series of chemical reactions. What is the primary was that enzymes affect these reactions? Question 3: What role does an enzyme play when the body processes sucrose (table sugar) into glucose and fructose? Question 4: The role of an enzyme in a chemical reaction is to change of the reaction? Question 5: The graph below shows how the activity of an enzyme changes over a range of pH values. Interpret the graph. Question 6: An amoeba in a pond engulfs and consumes a paramecium. The amoeba uses which type of molecule to quickly break down the organic molecules in the paramecium?
Background for questions 7 and 8: Biology students investigated various human digestive enzymes. The table below summarizes
the functions of several different digestive enzymes.
Enzyme
Function
salivary amylase
begins to break down starch into smaller polysaccharides
or the disaccharide maltose
pepsin
begins to break down proteins into small polypeptides
pancreatic amylase
continues to break down starch and smaller
polysaccharides into disaccharides
lipase
breaks down fats into glycerol, fatty acids, or glycerides
aminopeptidase
breaks down small polypeptides into amino acids
The students conducted experiments to study digestive enzyme activity. In the first experiment, the
students observed the rate at which salivary amylase breaks down starch (the substrate) in solutions with
different pH values. The students then performed the same type of experiment with pepsin. The graph
below shows the students’ results for the two experiments.
Question 7: Salivary amylase breaks down which class of organic molecules? Question 8: Describe the effect of pH on the functioning of salivary amylase. Standard: 1.3 - Explain the role of enzymes as catalysts that lower the activation energy of biochemical
reactions. Identify factors, such as pH and temperature, that have an effect on enzymes.
Catalase is an enzyme that protects cells from damage by helping convert the toxin hydrogen peroxide
(H2O2) into water (H2O) and oxygen (O2). A student is investigating how different pH values and different
temperatures affect catalase activity. The table below shows the student’s data.
Catalase Experiment Data
Test Amount of Amount of
pH of
Temperature
Tube Catalase
Hydrogen Solution of Solution
(drops)
Peroxide
(°C)
(mL)
Relative Rate
of Reaction
1
10
3
1
5
no reaction
2
10
3
1
30
no reaction
3
10
3
1
60
no reaction
4
10
3
3
5
5
10
3
3
30
slow reaction
6
10
3
3
60
no reaction
7
10
3
7
5
slow reaction
8
10
3
7
30
rapid reaction
9
10
3
7
60
no reaction
a.
very slow reaction
Identify the test tube that most likely has physical conditions similar to the conditions in human
cells. Explain your answer.
b. Describe how catalase activity changes as pH decreases. Use data from the table to support your
answer.
c. Describe how catalase activity changes as temperature increases. Use data from the table to
support your answer.
d. Explain why temperature affects catalase activity in the way you described in part (c).
Performance Indicators Rubric Chemistry of Life Needs Improvement Proficient Describes the basic purpose Describes the function of of an enzyme enzymes and identifies some factors that have an effect on enzymes Advanced Explains the effects enzymes can have on biological processes and how environments can have an effect on the activity of enzymes