AP BIOLOGY UNIT 4 TEST QUESTIONS
WITH VERIFIED ANSWERS
Certain chemicals, including sodium fluoride (NaF), are capable of inhibiting specific
steps of glycolysis. Figure 1 shows the steps of the glycolysis pathway, indicating
where various macromolecules enter the pathway as well as the specific reaction
inhibited by NaF. Based on Figure 1, the net number of ATP molecules produced
during glycolysis from the metabolism of a single glucose molecule is closest to
which of the following? - ANSWER-2
Certain chemicals, including sodium fluoride (NaF), are capable of inhibiting specific
steps of glycolysis. Figure 1 shows the steps of the glycolysis pathway, indicating
where various macromolecules enter the pathway as well as the specific reaction
inhibited by NaF. An increase in the concentration of protons in the cytosol will most
likely have which of the following effects on glycolysis? - ANSWER-Glycolytic
enzymes will denature as a result of the increased H+ concentration.
Certain chemicals, including sodium fluoride (NaF), are capable of inhibiting specific
steps of glycolysis. Figure 1 shows the steps of the glycolysis pathway, indicating
where various macromolecules enter the pathway as well as the specific reaction
inhibited by NaF. Tarui disease is an inherited disorder that is caused by mutations
in PFKM, the gene that encodes a subunit of phosphofructokinase, an enzyme in the
glycolysis pathway. Individuals with Tarui disease produce little or no functional
phosphofructokinase in skeletal muscle cells. Based on Figure 1, which of the
following best explains why a low carbohydrate diet is recommended for those with
Tarui disease? - ANSWER-Carbohydrate metabolism requires all the reactions of
glycolysis, and amino acids and fatty acids do not.
Based on the data in Figure 1, which of the following most likely represents the
change in energy that occurs when ATP hydrolysis is coupled with the
phosphorylation of a substrate? - ANSWER-Line 1 represents ATP hydrolysis, and
line 4 represents phosphorylation of a substrate.
Which of the following statements best helps explain the reaction specificity of an
enzyme? - ANSWER-The shape and charge of the substrates are compatible with
the active site of the enzyme.
Which of the following can be used to determine the rate of enzyme-catalyzed
reactions? - ANSWER-Rate of disappearance of the substrate
Gelatin is a protein that is derived from collagen which is found in the bones, skin,
and connective tissue of animals. To investigate the ability of various enzymes to
digest gelatin, a group of students set up an assay involving camera film. Camera
film contains gelatin and appears black when exposed to light but turns clear as the
gelatin gets broken down. The students incubated pieces of exposed camera film in
test tubes, each containing one of three different enzyme solutions (trypsin, lipase, or
amylase) as indicated in Figure 1. The students recorded the time it took for the
enzymes to digest the gelatin in each test tube, turning the film from black to clear.
, Which of the following would be the most appropriate control for this experiment? -
ANSWER-A test tube containing a piece of exposed camera film submerged in water
The following questions refer to an experiment that is set up to determine the relative
volume of O2 consumed by germinating and nongerminating (dry) pea seeds at two
different temperatures. The change in volume is detected by using a respirometer
over a given period of time. The data are given below. The rate of oxygen
consumption in germinating pea seeds at 26ºC is - ANSWER-0.05 mL / min
The following questions refer to an experiment that is set up to determine the relative
volume of O2 consumed by germinating and nongerminating (dry) pea seeds at two
different temperatures. The change in volume is detected by using a respirometer
over a given period of time. The data are given below. Which of the following
conclusions is best supported by the data? - ANSWER-In pea seeds an increase in
temperature results in an increase in oxygen consumption.
The enzyme hexokinase catalyzes the conversion of glucose to glucose-6-
phosphate, which is an important step in glycolysis. The reaction involves the
transfer of a phosphate group from ATP to glucose. Either a glucose molecule or a
water molecule can fit in the active site of hexokinase. The presence of a water
molecule in hexokinase's active site would result in the hydrolysis of ATP to ADP
instead of the conversion of glucose to glucose-6-phosphate.
Which of the following statements best helps explain the reaction specificity of
hexokinase? - ANSWER-Glucose has the right shape and charge to cause
hexokinase to undergo a structural change needed for catalysis, whereas water does
not.
Pyruvate kinase, a key enzyme in the glycolysis pathway, is inhibited by the amino
acid alanine. The ability of alanine to inhibit the enzyme is not affected by increasing
the concentration of substrate.
Which of the following best explains the mechanism by which alanine inhibits
pyruvate kinase activity? - ANSWER-Alanine binds to an allosteric site of the
enzyme, changing the shape of the enzyme's active site.
In an experiment, a scientist isolates mitochondria from living cells and suspends
them in two different buffered solutions. One solution is maintained at pH 4, while the
other solution is maintained at pH 9. The scientist finds that mitochondria in the
solution at pH 4 continue to produce ATP but those in the pH 9 solution do not. The
results of the experiment can be used as evidence in support of which of the
following scientific claims about mitochondrial activity? - ANSWER-ATP production in
mitochondria requires a hydrogen ion gradient that favors movement of protons into
the mitochondrial matrix.
Which of the following questions will best direct an investigation of the mechanism of
ATP synthase? - ANSWER-Is the phosphorylation of ADP by ATP synthase
dependent on the formation of a proton gradient?
Which of the following describes a metabolic consequence of a shortage of oxygen
in muscle cells? - ANSWER-A buildup of lactic acid in the muscle tissue due to
fermentation
WITH VERIFIED ANSWERS
Certain chemicals, including sodium fluoride (NaF), are capable of inhibiting specific
steps of glycolysis. Figure 1 shows the steps of the glycolysis pathway, indicating
where various macromolecules enter the pathway as well as the specific reaction
inhibited by NaF. Based on Figure 1, the net number of ATP molecules produced
during glycolysis from the metabolism of a single glucose molecule is closest to
which of the following? - ANSWER-2
Certain chemicals, including sodium fluoride (NaF), are capable of inhibiting specific
steps of glycolysis. Figure 1 shows the steps of the glycolysis pathway, indicating
where various macromolecules enter the pathway as well as the specific reaction
inhibited by NaF. An increase in the concentration of protons in the cytosol will most
likely have which of the following effects on glycolysis? - ANSWER-Glycolytic
enzymes will denature as a result of the increased H+ concentration.
Certain chemicals, including sodium fluoride (NaF), are capable of inhibiting specific
steps of glycolysis. Figure 1 shows the steps of the glycolysis pathway, indicating
where various macromolecules enter the pathway as well as the specific reaction
inhibited by NaF. Tarui disease is an inherited disorder that is caused by mutations
in PFKM, the gene that encodes a subunit of phosphofructokinase, an enzyme in the
glycolysis pathway. Individuals with Tarui disease produce little or no functional
phosphofructokinase in skeletal muscle cells. Based on Figure 1, which of the
following best explains why a low carbohydrate diet is recommended for those with
Tarui disease? - ANSWER-Carbohydrate metabolism requires all the reactions of
glycolysis, and amino acids and fatty acids do not.
Based on the data in Figure 1, which of the following most likely represents the
change in energy that occurs when ATP hydrolysis is coupled with the
phosphorylation of a substrate? - ANSWER-Line 1 represents ATP hydrolysis, and
line 4 represents phosphorylation of a substrate.
Which of the following statements best helps explain the reaction specificity of an
enzyme? - ANSWER-The shape and charge of the substrates are compatible with
the active site of the enzyme.
Which of the following can be used to determine the rate of enzyme-catalyzed
reactions? - ANSWER-Rate of disappearance of the substrate
Gelatin is a protein that is derived from collagen which is found in the bones, skin,
and connective tissue of animals. To investigate the ability of various enzymes to
digest gelatin, a group of students set up an assay involving camera film. Camera
film contains gelatin and appears black when exposed to light but turns clear as the
gelatin gets broken down. The students incubated pieces of exposed camera film in
test tubes, each containing one of three different enzyme solutions (trypsin, lipase, or
amylase) as indicated in Figure 1. The students recorded the time it took for the
enzymes to digest the gelatin in each test tube, turning the film from black to clear.
, Which of the following would be the most appropriate control for this experiment? -
ANSWER-A test tube containing a piece of exposed camera film submerged in water
The following questions refer to an experiment that is set up to determine the relative
volume of O2 consumed by germinating and nongerminating (dry) pea seeds at two
different temperatures. The change in volume is detected by using a respirometer
over a given period of time. The data are given below. The rate of oxygen
consumption in germinating pea seeds at 26ºC is - ANSWER-0.05 mL / min
The following questions refer to an experiment that is set up to determine the relative
volume of O2 consumed by germinating and nongerminating (dry) pea seeds at two
different temperatures. The change in volume is detected by using a respirometer
over a given period of time. The data are given below. Which of the following
conclusions is best supported by the data? - ANSWER-In pea seeds an increase in
temperature results in an increase in oxygen consumption.
The enzyme hexokinase catalyzes the conversion of glucose to glucose-6-
phosphate, which is an important step in glycolysis. The reaction involves the
transfer of a phosphate group from ATP to glucose. Either a glucose molecule or a
water molecule can fit in the active site of hexokinase. The presence of a water
molecule in hexokinase's active site would result in the hydrolysis of ATP to ADP
instead of the conversion of glucose to glucose-6-phosphate.
Which of the following statements best helps explain the reaction specificity of
hexokinase? - ANSWER-Glucose has the right shape and charge to cause
hexokinase to undergo a structural change needed for catalysis, whereas water does
not.
Pyruvate kinase, a key enzyme in the glycolysis pathway, is inhibited by the amino
acid alanine. The ability of alanine to inhibit the enzyme is not affected by increasing
the concentration of substrate.
Which of the following best explains the mechanism by which alanine inhibits
pyruvate kinase activity? - ANSWER-Alanine binds to an allosteric site of the
enzyme, changing the shape of the enzyme's active site.
In an experiment, a scientist isolates mitochondria from living cells and suspends
them in two different buffered solutions. One solution is maintained at pH 4, while the
other solution is maintained at pH 9. The scientist finds that mitochondria in the
solution at pH 4 continue to produce ATP but those in the pH 9 solution do not. The
results of the experiment can be used as evidence in support of which of the
following scientific claims about mitochondrial activity? - ANSWER-ATP production in
mitochondria requires a hydrogen ion gradient that favors movement of protons into
the mitochondrial matrix.
Which of the following questions will best direct an investigation of the mechanism of
ATP synthase? - ANSWER-Is the phosphorylation of ADP by ATP synthase
dependent on the formation of a proton gradient?
Which of the following describes a metabolic consequence of a shortage of oxygen
in muscle cells? - ANSWER-A buildup of lactic acid in the muscle tissue due to
fermentation
