Question 1

The location in which the enzyme and substrate complexes is called the

Accepted Answer

A)  active site. 
B)  inhibitor site. 
C)  receptor site. 
D)  enzyme-substrate complex. 
E)  enzyme-inhibitor complex. 
A)  active site. 
B)  inhibitor site. 
C)  receptor site. 
D)  enzyme-substrate complex. 
E)  enzyme-inhibitor complex.

Question 2

Which of the following is an accurate statement about metabolic pathways?

Accepted Answer

A)  Products are the input molecules. 
B)  Metabolic pathways tend to be unorganized and unregulated. 
C)  The same enzyme catalyzes all the reactions in a pathway. 
D)  Metabolic pathways often intersect one another. 
E)  A constant supply of new enzymes must be produced to keep the metabolic pathway active. 
A)  Products are the input molecules. 
B)  Metabolic pathways tend to be unorganized and unregulated. 
C)  The same enzyme catalyzes all the reactions in a pathway. 
D)  Metabolic pathways often intersect one another. 
E)  A constant supply of new enzymes must be produced to keep the metabolic pathway active.

Question 3

The amount of energy available to do work after a chemical reaction has occurred is called

Accepted Answer

A)  entropy. 
B)  metabolic energy. 
C)  potential energy. 
D)  kinetic energy. 
E)  free energy. 
A)  entropy. 
B)  metabolic energy. 
C)  potential energy. 
D)  kinetic energy. 
E)  free energy.

Question 4

During an enzymatic reaction, what happens to the enzyme?

Accepted Answer

A)  It becomes the product. 
B)  It becomes the substrate. 
C)  It is used up. 
D)  The enzyme and the substrate form a permanent complex. 
E)  The enzyme and the substrate form a temporary complex. 
A)  It becomes the product. 
B)  It becomes the substrate. 
C)  It is used up. 
D)  The enzyme and the substrate form a permanent complex. 
E)  The enzyme and the substrate form a temporary complex.

Question 5

Most cells use a tremendous amount of ATP

Accepted Answer

A)  so our bodies therefore produce and maintain a huge amount of ATP in storage. 
B)  but the amount of stored ATP is not great because our body constantly generates ATP from ADP + P. 
C)  mainly because ATP is not very efficient as an energy currency. 
D)  but only for chemical work; transport and mechanical work must use a different form of energy. 
A)  so our bodies therefore produce and maintain a huge amount of ATP in storage. 
B)  but the amount of stored ATP is not great because our body constantly generates ATP from ADP + P. 
C)  mainly because ATP is not very efficient as an energy currency. 
D)  but only for chemical work; transport and mechanical work must use a different form of energy.

Question 6

Which energy association is correct?

Accepted Answer

A)  Kinetic energy is energy of motion. 
B)  Water stored behind a dam is an example of kinetic energy. 
C)  Energy in the chemical bonds of a molecule is kinetic energy. 
D)  Potential energy must be used immediately or it is lost. 
E)  Light energy is a form of chemical energy. 
A)  Kinetic energy is energy of motion. 
B)  Water stored behind a dam is an example of kinetic energy. 
C)  Energy in the chemical bonds of a molecule is kinetic energy. 
D)  Potential energy must be used immediately or it is lost. 
E)  Light energy is a form of chemical energy.

Question 7

The reason an increase in substrate concentration does not increase the reaction rate indefinitely is because

Accepted Answer

A)  eventually the enzyme will no longer recognize the substrate. 
B)  the active site will become saturated with substrate and the enzyme will not be able to go any faster. 
C)  another enzyme will take advantage of the excess substrate and use it for a different reaction. 
D)  enzymes cannot be used more than once in a reaction. 
E)  the enzyme will become denatured. 
A)  eventually the enzyme will no longer recognize the substrate. 
B)  the active site will become saturated with substrate and the enzyme will not be able to go any faster. 
C)  another enzyme will take advantage of the excess substrate and use it for a different reaction. 
D)  enzymes cannot be used more than once in a reaction. 
E)  the enzyme will become denatured.

Question 8

The specificity of an enzyme to a substrate is currently best explained by

Accepted Answer

A)  the "lock and key" model. 
B)  the induced-fit model. 
C)  the allosteric model. 
D)  the receptor model. 
E)  the synthase complex model. 
A)  the "lock and key" model. 
B)  the induced-fit model. 
C)  the allosteric model. 
D)  the receptor model. 
E)  the synthase complex model.

Question 9

Most enzymes are

Accepted Answer

A)  lipid molecules. 
B)  carbohydrate molecules. 
C)  protein molecules. 
D)  DNA molecules. 
E)  ATP molecules. 
A)  lipid molecules. 
B)  carbohydrate molecules. 
C)  protein molecules. 
D)  DNA molecules. 
E)  ATP molecules.

Question 10

The removal of electrons and/or hydrogen atoms from a substrate is called what?

Accepted Answer

A)  reduction 
B)  oxidation 
C)  phosphorylation 
D)  metabolism 
E)  an enzyme-substrate complex 
A)  reduction 
B)  oxidation 
C)  phosphorylation 
D)  metabolism 
E)  an enzyme-substrate complex

Question 11

Which of the following statements is true concerning enzymatic activity?

Accepted Answer

A)  Each enzyme works well within a wide range of pH values. 
B)  Increasing temperatures has no effect on enzyme activity. 
C)  As the temperature decreases, most enzymatic reactions will still proceed at the same rate. 
D)  Enzymatic reactions proceed quite slowly. 
E)  Enzyme activity increases as substrate concentration increases until the maximum rate is achieved. 
A)  Each enzyme works well within a wide range of pH values. 
B)  Increasing temperatures has no effect on enzyme activity. 
C)  As the temperature decreases, most enzymatic reactions will still proceed at the same rate. 
D)  Enzymatic reactions proceed quite slowly. 
E)  Enzyme activity increases as substrate concentration increases until the maximum rate is achieved.

Question 12

Less energy is needed to bring about a reaction when an enzyme is present.

Accepted Answer

A) True 
 B)False

Question 13

The main reason that ATP is considered the energy currency in cells is because it

Accepted Answer

A)  is a small molecule. 
B)  carries a positive charge. 
C)  contains accessible energy in phosphate bonds. 
D)  contains an adenine base. 
E)  contains a sugar ring. 
A)  is a small molecule. 
B)  carries a positive charge. 
C)  contains accessible energy in phosphate bonds. 
D)  contains an adenine base. 
E)  contains a sugar ring.

Question 14

In feedback inhibition of a metabolic pathway, where does the inhibitor bind?

Accepted Answer

A)  to the substrate of the first reaction 
B)  to the product of the first reaction 
C)  to the enzyme of the first reaction 
D)  to the enzyme of the last reaction 
E)  to a substrate or the product of the last reaction 
A)  to the substrate of the first reaction 
B)  to the product of the first reaction 
C)  to the enzyme of the first reaction 
D)  to the enzyme of the last reaction 
E)  to a substrate or the product of the last reaction

Question 15

Energy, but not chemicals, may cycle through living things.

Accepted Answer

A) True 
 B)False

Question 16

Lactose is milk sugar that is broken down by the enzyme lactase. The reason that some people are "lactose intolerant" could be because

Accepted Answer

A)  the enzyme lactase only works in the laboratory, not in the human body. 
B)  the pH of the digestive system does not allow lactase to function properly. 
C)  the temperature of the digestive system does not allow lactase to function properly. 
D)  they drink too much milk and have inactivated the lactase in their digestive system. 
E)  they are missing the enzyme lactase in their digestive system. 
A)  the enzyme lactase only works in the laboratory, not in the human body. 
B)  the pH of the digestive system does not allow lactase to function properly. 
C)  the temperature of the digestive system does not allow lactase to function properly. 
D)  they drink too much milk and have inactivated the lactase in their digestive system. 
E)  they are missing the enzyme lactase in their digestive system.

Question 17

If there are 12 different intermediate products produced during production of a molecule in a cell, we can expect that there

Accepted Answer

A)  is one enzyme that carries this process through all 12 stages to the end product. 
B)  are about 12 enzymes, at least one responsible for each step in the metabolic pathway. 
C)  is one enzyme for degradation and another enzyme for synthesis. 
D)  there may not be any enzymes involved if this is a natural cell product. 
E)  must be 12 different raw materials combined in the cell by one enzyme. 
A)  is one enzyme that carries this process through all 12 stages to the end product. 
B)  are about 12 enzymes, at least one responsible for each step in the metabolic pathway. 
C)  is one enzyme for degradation and another enzyme for synthesis. 
D)  there may not be any enzymes involved if this is a natural cell product. 
E)  must be 12 different raw materials combined in the cell by one enzyme.

Question 18

The term metabolism refers to all of the chemical reactions that occur in a cell.

Accepted Answer

A) True 
 B)False

Question 19

Whether or not an enzyme is present and active within a cell depends on

Accepted Answer

A)  if the gene for the enzyme has been turned on and the enzyme made. 
B)  if the enzyme has been activated or inactivated. 
C)  whether an inhibitor is bound to the enzyme. 
D)  whether the necessary cofactor is present. 
E)  All of the answer choices could affect enzyme activity. 
A)  if the gene for the enzyme has been turned on and the enzyme made. 
B)  if the enzyme has been activated or inactivated. 
C)  whether an inhibitor is bound to the enzyme. 
D)  whether the necessary cofactor is present. 
E)  All of the answer choices could affect enzyme activity.

Question 20

In a coupled reaction, some of the energy released in one reaction is used to drive another reaction forward.

Accepted Answer

A) True 
 B)False

Exam 6: Metabolism: Energy and Enzymes

The location in which the enzyme and substrate complexes is called the

Which of the following is an accurate statement about metabolic pathways?

The amount of energy available to do work after a chemical reaction has occurred is called

During an enzymatic reaction, what happens to the enzyme?

Most cells use a tremendous amount of ATP

Which energy association is correct?

The reason an increase in substrate concentration does not increase the reaction rate indefinitely is because

The specificity of an enzyme to a substrate is currently best explained by

Most enzymes are

The removal of electrons and/or hydrogen atoms from a substrate is called what?

Which of the following statements is true concerning enzymatic activity?

Less energy is needed to bring about a reaction when an enzyme is present.

The main reason that ATP is considered the energy currency in cells is because it

In feedback inhibition of a metabolic pathway, where does the inhibitor bind?

Energy, but not chemicals, may cycle through living things.

Lactose is milk sugar that is broken down by the enzyme lactase. The reason that some people are "lactose intolerant" could be because

If there are 12 different intermediate products produced during production of a molecule in a cell, we can expect that there

The term metabolism refers to all of the chemical reactions that occur in a cell.

Whether or not an enzyme is present and active within a cell depends on

In a coupled reaction, some of the energy released in one reaction is used to drive another reaction forward.

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