AP Biology Benchmark #7 Enzymes & ATP

Last updated 4 months ago

19 questions

1

2

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AP Biology Benchmark #7 Enzymes & ATP

Last updated 4 months ago

19 questions

1

1

Use the following information to answer questions #

Rate of an enzyme-catalyzed reaction as a function of varying reactant concentration, with the concentration of enzyme constant.

1

Use the following information to answer the question below.

Activity of various enzymes at various temperatures (a) and at various pH (b)

1

A series of enzymes catalyze the reactions in the metabolic pathway X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme.

1

In a metabolic pathway, succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, a substance that resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the amount of succinate molecules to those of malonic acid reduces the inhibitory effect of malonic acid. 

1

This is a model of a metabolic pathway involving molecules 1 - 6 and enzymes A - E.

4

3

This is a graph of an enzyme mediated reaction.

7

1

4

2

Some people argue that biochemical pathways are too complex to have evolved because all intermediate steps in a given pathway must be present to produce the final product. Critique this argument.

Which of the following statements describes a common characteristic of catabolic pathways?

They require energy from ATP hydrolysis to break down polymers into monomers.

They are exergonic and provide energy that can be used to produce ATP from ADP and Pi.

They combine small molecules into larger, more energy-rich molecules.

They are endergonic and release energy that can be used for cellular work.

What environmental condition typically increases the rate of enzyme activity?

Decreased nutrient availability

Decreased oxygen levels

Increased acidity

Increased temperature within optimal range

When ATP releases some energy, it also releases inorganic phosphate. What happens to the inorganic phosphate in the cell?

It is used only to regenerate more ATP.

It may be used to form a phosphorylated intermediate.

It is secreted as waste.

It enters the nucleus to be incorporated in a nucleotide.

Which of the following statements describes a key component of the induced fit hypothesis of enzyme catalysis?

Binding of substrate to the active site changes the shape of the active site of an enzyme.

Binding of an activator molecule changes the shape of the active site of an enzyme.

Substrate binds to an allosteric site rather than to the active site of an enzyme.

The conformation of the active site is determined by the tertiary or quaternary structure of the enzyme.

Use the following information to answer questions #

Rate of an enzyme-catalyzed reaction as a function of varying reactant concentration, with the concentration of enzyme constant.

1

Use the following information to answer the question below.

Activity of various enzymes at various temperatures (a) and at various pH (b)

1

A series of enzymes catalyze the reactions in the metabolic pathway X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme.

In a metabolic pathway, succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, a substance that resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the amount of succinate molecules to those of malonic acid reduces the inhibitory effect of malonic acid. 

This is a model of a metabolic pathway involving molecules 1 - 6 and enzymes A - E.

4

Describe what is occurring in the red box (outlined not shaded box) and explain its role in this metabolic pathway.

4

Imagine a medical condition that denatured Enzyme C. Predict how that would affect the concentrations of molecule 1 and molecule 2, if this were a closed system. Explain your answers for each.

3

This model demonstrates feedback inhibition of an anabolic pathway. With that in mind, explain how ATP might be involved in feedback inhibition of a catabolic pathway. Explain your answer.

This is a graph of an enzyme mediated reaction.

7

Explain the molecular events occurring at EACH stage of this reaction profile. Be clear about how the events of each stage are different from the other. Use appropriate vocabulary.

1

Assume that the graphed reaction is occurring at optimal temperature and pH. Describe how the graph would change if the pH were to change.

4

Explain your previous answer detailing specific, physical changes to the participants of the reaction and describing the results of these changes.

Some people argue that biochemical pathways are too complex to have evolved because all intermediate steps in a given pathway must be present to produce the final product. Critique this argument.

Which of the following statements describes a common characteristic of catabolic pathways?

They require energy from ATP hydrolysis to break down polymers into monomers.

They are exergonic and provide energy that can be used to produce ATP from ADP and Pi.

They combine small molecules into larger, more energy-rich molecules.

They are endergonic and release energy that can be used for cellular work.

What environmental condition typically increases the rate of enzyme activity?

Decreased nutrient availability

Decreased oxygen levels

Increased acidity

Increased temperature within optimal range

When ATP releases some energy, it also releases inorganic phosphate. What happens to the inorganic phosphate in the cell?

It is used only to regenerate more ATP.

It may be used to form a phosphorylated intermediate.

It is secreted as waste.

It enters the nucleus to be incorporated in a nucleotide.

Which of the following is the most correct interpretation of the figure?

ADP + Pi are a set of molecules that store energy for catabolism.

Energy from catabolism can be used directly for performing cellular work.

Pi acts as a shuttle molecule to move energy from ATP to ADP.

ATP is a molecule that acts as an intermediary to store energy for cellular work.

How do cells use the ATP cycle illustrated in the figure?

Cells use the cycle primarily to generate heat.

Cells use the cycle to recycle ADP and phosphate.

Cells use the cycle to recycle energy released by ATP hydrolysis.

Cells use the cycle to recycle ADP, phosphate, and the energy released by ATP hydrolysis.

Which of the following statements describes a key component of the induced fit hypothesis of enzyme catalysis?

Binding of substrate to the active site changes the shape of the active site of an enzyme.

Binding of an activator molecule changes the shape of the active site of an enzyme.

Substrate binds to an allosteric site rather than to the active site of an enzyme.

The conformation of the active site is determined by the tertiary or quaternary structure of the enzyme.

For the enzyme-catalyzed reaction shown in the figure, if the initial reactant concentration is 1.0 micromolar, which of these treatments will cause the greatest increase in the rate of the reaction?

doubling the enzyme concentration

cooling the reaction by 10°C

doubling the activation energy needed

increasing the concentration of reactants to 10.0 micromolar, while reducing the concentration of enzyme by 1/2

Which temperature and pH profile curves on the graphs are most likely associated with an enzyme isolated from a human stomach where conditions are strongly acid?

curves 3 and 4

curves 2 and 4

curves 1 and 4

curves 1 and 5

With respect to the enzyme that converts X to Y, substance A functions as ________.

the substrate

an intermediate

a competitive inhibitor

an allosteric inhibitor

What is substance X?

an intermediate

the product

an allosteric inhibitor

a substrate

Select the correct identification of the molecules described in the reaction.

Succinate dehydrogenase is the enzyme, and malonic acid is the substrate in the reaction.

Succinate is the substrate, and fumarate is the product in the reaction.

Succinate dehydrogenase is the enzyme, and fumarate is the substrate in the reaction.

Fumarate is the product, and malonic acid is a noncompetitive inhibitor in the reaction.

What role does malonic acid play with respect to succinate dehydrogenase?

Malonic acid is a noncompetitive inhibitor.

Malonic acid blocks the binding of fumarate.

Malonic acid is an allosteric regulator.

Malonic acid is a competitive inhibitor.

Describe what is occurring in the red box (outlined not shaded box) and explain its role in this metabolic pathway.

Imagine a medical condition that denatured Enzyme C. Predict how that would affect the concentrations of molecule 1 and molecule 2, if this were a closed system. Explain your answers for each.

This model demonstrates feedback inhibition of an anabolic pathway. With that in mind, explain how ATP might be involved in feedback inhibition of a catabolic pathway. Explain your answer.

Explain the molecular events occurring at EACH stage of this reaction profile. Be clear about how the events of each stage are different from the other. Use appropriate vocabulary.

Assume that the graphed reaction is occurring at optimal temperature and pH. Describe how the graph would change if the pH were to change.

Explain your previous answer detailing specific, physical changes to the participants of the reaction and describing the results of these changes.

Which of the following is the most correct interpretation of the figure?

ADP + Pi are a set of molecules that store energy for catabolism.

Energy from catabolism can be used directly for performing cellular work.

Pi acts as a shuttle molecule to move energy from ATP to ADP.

ATP is a molecule that acts as an intermediary to store energy for cellular work.

How do cells use the ATP cycle illustrated in the figure?

Cells use the cycle primarily to generate heat.

Cells use the cycle to recycle ADP and phosphate.

Cells use the cycle to recycle energy released by ATP hydrolysis.

Cells use the cycle to recycle ADP, phosphate, and the energy released by ATP hydrolysis.

For the enzyme-catalyzed reaction shown in the figure, if the initial reactant concentration is 1.0 micromolar, which of these treatments will cause the greatest increase in the rate of the reaction?

doubling the enzyme concentration

cooling the reaction by 10°C

doubling the activation energy needed

increasing the concentration of reactants to 10.0 micromolar, while reducing the concentration of enzyme by 1/2

Which temperature and pH profile curves on the graphs are most likely associated with an enzyme isolated from a human stomach where conditions are strongly acid?

curves 3 and 4

curves 2 and 4

curves 1 and 4

curves 1 and 5

With respect to the enzyme that converts X to Y, substance A functions as ________.

the substrate

an intermediate

a competitive inhibitor

an allosteric inhibitor

What is substance X?

an intermediate

the product

an allosteric inhibitor

a substrate

Select the correct identification of the molecules described in the reaction.

Succinate dehydrogenase is the enzyme, and malonic acid is the substrate in the reaction.

Succinate is the substrate, and fumarate is the product in the reaction.

Succinate dehydrogenase is the enzyme, and fumarate is the substrate in the reaction.

Fumarate is the product, and malonic acid is a noncompetitive inhibitor in the reaction.

What role does malonic acid play with respect to succinate dehydrogenase?

Malonic acid is a noncompetitive inhibitor.

Malonic acid blocks the binding of fumarate.

Malonic acid is an allosteric regulator.

Malonic acid is a competitive inhibitor.