AP BIO QUIZ 3.1-3.3 CELLULAR
ENERGETICS (ENZYMES) EXAM
QUESTIONS AND ANSWERS
Which of the following statements best predicts the effect of increasing the
concentration of substrate (ethyl alcohol), while keeping the concentration of the
inhibitor (methyl alcohol) constant?
A
There will be an increase in formaldehyde because ADHactivity increases.
B
Competitive inhibition will be terminated because ethyl alcohol will bind to methyl
alcohol and decrease ADH activity.
C
The peptide bonds in the active site of the enzyme will be denatured, inhibiting the
enzyme.
D
Competitive inhibition will decrease because the proportion of the active sites
occupied by substrate will inc - ANSWER-D
Competitive inhibition will decrease because the proportion of the active sites
occupied by substrate will increase.
A researcher claims that different enzymes exhibit maximal function over different pH
ranges. To test the claim, the researcher carries out an experiment that includes
three different enzymes: pepsin, salivary amylase, and arginase. The results of the
experiment are represented in Figure 1.
Figure 1. The effect of pH on three different enzymes
Which of the following actions will provide the most appropriate negative control for
the experiment?
A
Repeating the experiment with a fourth enzyme
B
Repeating the experiment at several different temperatures
C
Repeating the experiment with denatured enzymes
D
Repeating the experiment using several different methods for measuring pH -
ANSWER-C
Repeating the experiment with denatured enzymes
The enzyme peroxidase is found in many organisms. It catalyzes the breakdown of
hydrogen peroxide into water and oxygen gas. The rate of peroxidase activity at
different pH values was assessed by students in the lab. The students' results are
shown in graph 1.
If the experiment is repeated at pH 11, the observed activity level of the enzyme will
most likely be
, A
the same as the level at pH 7
B
lower than the level at pH 9
C
greater than the level at pH 9
D
between the levels observed at pH 5 and pH 7. - ANSWER-B
lower than the level at pH 9
A researcher claims that increasing the environmental temperature by 10°C will
double the rate of an enzyme-catalyzed reaction. To test the claim, the researcher
designs an experiment that uses a particular enzyme isolated from plants. The
design of the experiment is presented in Table 1. For each test tube in the
experiment, the researcher will measure the rate of product formation.
Which of the following statements best helps justify the inclusion of test tube 5 as a
control in the experiment?
A
It will provide a measurement of product formation in the absence of the substrate.
B
It will provide a measurement of product formation in the presence of a denatured
enzyme.
C
It will show the effect of doubling the amount of substrate on the rate of product
formation.
D
It will show the effect of increased enzyme activity on the rate of product formation. -
ANSWER-B
It will provide a measurement of product formation in the presence of a denatured
enzyme.
Protein digestion in humans is primarily carried out by three enzymes. Pepsin is
found in the stomach (pH2), where it aids in the breakdown of large proteins into
smaller peptides, while trypsin and chymotrypsin are found in the small intestine
(pH8), where they aid in the further breakdown of the proteins into amino acids and
dipeptides that can be absorbed into the bloodstream. Graph 1 shows the effect of
pH on the activity levels of the three enzymes.
Which of the following best predicts how the structure and function of pepsin will
change as it enters the small intestine?
A
Pepsin will not change in shape and will continue to break down proteins in the small
intestine.
B
Pepsin will not change in shape but may not work due to the basic environment of
the small intestine.
C
ENERGETICS (ENZYMES) EXAM
QUESTIONS AND ANSWERS
Which of the following statements best predicts the effect of increasing the
concentration of substrate (ethyl alcohol), while keeping the concentration of the
inhibitor (methyl alcohol) constant?
A
There will be an increase in formaldehyde because ADHactivity increases.
B
Competitive inhibition will be terminated because ethyl alcohol will bind to methyl
alcohol and decrease ADH activity.
C
The peptide bonds in the active site of the enzyme will be denatured, inhibiting the
enzyme.
D
Competitive inhibition will decrease because the proportion of the active sites
occupied by substrate will inc - ANSWER-D
Competitive inhibition will decrease because the proportion of the active sites
occupied by substrate will increase.
A researcher claims that different enzymes exhibit maximal function over different pH
ranges. To test the claim, the researcher carries out an experiment that includes
three different enzymes: pepsin, salivary amylase, and arginase. The results of the
experiment are represented in Figure 1.
Figure 1. The effect of pH on three different enzymes
Which of the following actions will provide the most appropriate negative control for
the experiment?
A
Repeating the experiment with a fourth enzyme
B
Repeating the experiment at several different temperatures
C
Repeating the experiment with denatured enzymes
D
Repeating the experiment using several different methods for measuring pH -
ANSWER-C
Repeating the experiment with denatured enzymes
The enzyme peroxidase is found in many organisms. It catalyzes the breakdown of
hydrogen peroxide into water and oxygen gas. The rate of peroxidase activity at
different pH values was assessed by students in the lab. The students' results are
shown in graph 1.
If the experiment is repeated at pH 11, the observed activity level of the enzyme will
most likely be
, A
the same as the level at pH 7
B
lower than the level at pH 9
C
greater than the level at pH 9
D
between the levels observed at pH 5 and pH 7. - ANSWER-B
lower than the level at pH 9
A researcher claims that increasing the environmental temperature by 10°C will
double the rate of an enzyme-catalyzed reaction. To test the claim, the researcher
designs an experiment that uses a particular enzyme isolated from plants. The
design of the experiment is presented in Table 1. For each test tube in the
experiment, the researcher will measure the rate of product formation.
Which of the following statements best helps justify the inclusion of test tube 5 as a
control in the experiment?
A
It will provide a measurement of product formation in the absence of the substrate.
B
It will provide a measurement of product formation in the presence of a denatured
enzyme.
C
It will show the effect of doubling the amount of substrate on the rate of product
formation.
D
It will show the effect of increased enzyme activity on the rate of product formation. -
ANSWER-B
It will provide a measurement of product formation in the presence of a denatured
enzyme.
Protein digestion in humans is primarily carried out by three enzymes. Pepsin is
found in the stomach (pH2), where it aids in the breakdown of large proteins into
smaller peptides, while trypsin and chymotrypsin are found in the small intestine
(pH8), where they aid in the further breakdown of the proteins into amino acids and
dipeptides that can be absorbed into the bloodstream. Graph 1 shows the effect of
pH on the activity levels of the three enzymes.
Which of the following best predicts how the structure and function of pepsin will
change as it enters the small intestine?
A
Pepsin will not change in shape and will continue to break down proteins in the small
intestine.
B
Pepsin will not change in shape but may not work due to the basic environment of
the small intestine.
C
