Question 1

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

Accepted Answer

A)  Energy from catabolism can be used directly for performing cellular work. 
B)  ADP +   i are a set of molecules that store energy for catabolism. 
C)  ATP is a molecule that acts as an intermediary to store energy for cellular work. 
D)    i acts as a shuttle molecule to move energy from ATP to ADP. 
A)  Energy from catabolism can be used directly for performing cellular work. 
B)  ADP +   i are a set of molecules that store energy for catabolism. 
C)  ATP is a molecule that acts as an intermediary to store energy for cellular work. 
D)    i acts as a shuttle molecule to move energy from ATP to ADP.

Question 2

In addition to activating or inhibiting enzymes through allosteric regulation, what other means does a cell use to control enzymatic activity?

Accepted Answer

A)  localisation of enzymes into specific organelles or membranes 
B)  secretion of enzymes out of the cell 
C)  assembly of enzymes into large aggregates 
D)  altering internal pH 
A)  localisation of enzymes into specific organelles or membranes 
B)  secretion of enzymes out of the cell 
C)  assembly of enzymes into large aggregates 
D)  altering internal pH

Question 3

Most cells cannot harness heat to perform work because

Accepted Answer

A)  heat does not involve a transfer of energy. 
B)  cells do not have much thermal energy; they are relatively cool. 
C)  temperature is usually uniform throughout a cell. 
D)  heat can never be used to do work. 
A)  heat does not involve a transfer of energy. 
B)  cells do not have much thermal energy; they are relatively cool. 
C)  temperature is usually uniform throughout a cell. 
D)  heat can never be used to do work.

Question 4

Which of the following is true when comparing an uncatalysed reaction to the same reaction with a catalyst?

Accepted Answer

A)  The catalysed reaction will be slower. 
B)  The catalysed reaction will have the same ∆G. 
C)  The catalysed reaction will have higher activation energy. 
D)  The catalysed reaction will consume all of the catalyst. 
A)  The catalysed reaction will be slower. 
B)  The catalysed reaction will have the same ∆G. 
C)  The catalysed reaction will have higher activation energy. 
D)  The catalysed reaction will consume all of the catalyst.

Question 5

If an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur?

Accepted Answer

A)  Additional substrate will be formed. 
B)  The reaction will change from endergonic to exergonic. 
C)  The free energy of the system will change. 
D)  Nothing; the reaction will stay at equilibrium. 
A)  Additional substrate will be formed. 
B)  The reaction will change from endergonic to exergonic. 
C)  The free energy of the system will change. 
D)  Nothing; the reaction will stay at equilibrium.

Question 6

Which of the following metabolic processes can occur without a net influx of energy from some other process?

Accepted Answer

A)  ADP +   → ATP + H₂O 
B)  C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O 
C)  6CO₂ + 6H₂0 → C₆H₁₂O₆ + 6O₂ 
D)  Amino acids → Protein 
A)  ADP +   → ATP + H₂O 
B)  C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O 
C)  6CO₂ + 6H₂0 → C₆H₁₂O₆ + 6O₂ 
D)  Amino acids → Protein

Question 7

Which of the following is a primary function of the active site of an enzyme?

Accepted Answer

A)  It binds allosteric regulators of the enzyme. 
B)  It binds noncompetitive inhibitors of the enzyme. 
C)  It catalyses the reaction associated with the enzyme. 
D)  It is activated by the presence of the end product of the metabolic pathway in which the enzyme is involved. 
A)  It binds allosteric regulators of the enzyme. 
B)  It binds noncompetitive inhibitors of the enzyme. 
C)  It catalyses the reaction associated with the enzyme. 
D)  It is activated by the presence of the end product of the metabolic pathway in which the enzyme is involved.

Question 8

Which of the following molecules is most similar in structure to ATP?

Accepted Answer

A)  a pentose sugar 
B)  a DNA nucleotide 
C)  an RNA nucleotide 
D)  an amino acid with three phosphate groups attached 
A)  a pentose sugar 
B)  a DNA nucleotide 
C)  an RNA nucleotide 
D)  an amino acid with three phosphate groups attached

Question 9

If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to

Accepted Answer

A)  add more of the enzyme. 
B)  heat the solution to 90°C. 
C)  add more substrate. 
D)  add a noncompetitive inhibitor. 
A)  add more of the enzyme. 
B)  heat the solution to 90°C. 
C)  add more substrate. 
D)  add a noncompetitive inhibitor.

Question 10

Which of the following statements is true for a system at chemical equilibrium?

Accepted Answer

A)  The system consumes energy at a steady rate. 
B)  The system releases energy at a steady rate. 
C)  The kinetic energy of the system is zero. 
D)  The system can do no work. 
A)  The system consumes energy at a steady rate. 
B)  The system releases energy at a steady rate. 
C)  The kinetic energy of the system is zero. 
D)  The system can do no work.

Question 11

Characterisation of the complete three-dimensional structure of a newly purified protein suggests that it catalyses the breakdown of a large substrate. The protein consists of a single polypeptide chain. It has a large pocket that appears to be the binding site for the substrate and a smaller indentation that appears to be the binding site for a regulatory molecule. What do these structural observations suggest about the mechanism by which the activity of this protein is likely regulated?

Accepted Answer

A)  It is probably an enzyme that is regulated by noncompetitive inhibition. 
B)  It is probably a multi-subunit enzyme that is regulated by allosteric regulation. 
C)  It is probably an enzyme that is regulated by competitive inhibition. 
D)  It is probably an enzyme that is regulated by cooperativity. 
A)  It is probably an enzyme that is regulated by noncompetitive inhibition. 
B)  It is probably a multi-subunit enzyme that is regulated by allosteric regulation. 
C)  It is probably an enzyme that is regulated by competitive inhibition. 
D)  It is probably an enzyme that is regulated by cooperativity.

Question 12

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

Accepted Answer

A)  Substrate binds to an allosteric site rather than to the active site of an enzyme. 
B)  Binding of an activator molecule changes the shape of the active site of an enzyme. 
C)  The conformation of the active site is determined by the tertiary or quaternary structure of the enzyme. 
D)  Binding of substrate to the active site changes the shape of the active site of an enzyme. 
A)  Substrate binds to an allosteric site rather than to the active site of an enzyme. 
B)  Binding of an activator molecule changes the shape of the active site of an enzyme. 
C)  The conformation of the active site is determined by the tertiary or quaternary structure of the enzyme. 
D)  Binding of substrate to the active site changes the shape of the active site of an enzyme.

Question 13

Most cells cannot harness heat to perform work because ________.

Accepted Answer

A)  heat is not a form of energy 
B)  temperature is usually uniform throughout a cell 
C)  heat can never be used to do work 
D)  heat must remain constant during work 
A)  heat is not a form of energy 
B)  temperature is usually uniform throughout a cell 
C)  heat can never be used to do work 
D)  heat must remain constant during work

Question 14

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

Accepted Answer

A)  curves 1 and 4 
B)  curves 1 and 5 
C)  curves 2 and 4 
D)  curves 3 and 4 
A)  curves 1 and 4 
B)  curves 1 and 5 
C)  curves 2 and 4 
D)  curves 3 and 4

Question 15

Which of the following statements describes a central role that ATP plays in cellular metabolism?

Accepted Answer

A)  Hydrolysis of ATP provides an input of free energy for exergonic reactions. 
B)  ATP provides energy coupling between exergonic and endergonic reactions. 
C)  Hydrolysis of the terminal phosphate group stores free energy that is used for cellular work. 
D)  Its terminal phosphate bond is stronger than most covalent bonds in other biological macromolecules. 
A)  Hydrolysis of ATP provides an input of free energy for exergonic reactions. 
B)  ATP provides energy coupling between exergonic and endergonic reactions. 
C)  Hydrolysis of the terminal phosphate group stores free energy that is used for cellular work. 
D)  Its terminal phosphate bond is stronger than most covalent bonds in other biological macromolecules.

Question 16

A decrease in entropy is associated with which type of reaction?

Accepted Answer

A)  dehydration 
B)  catabolic 
C)  depolymerisation 
D)  hydrolysis 
A)  dehydration 
B)  catabolic 
C)  depolymerisation 
D)  hydrolysis

Question 17

Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as ________ is to ________.

Accepted Answer

A)  exergonic; spontaneous 
B)  exergonic; endergonic 
C)  free energy; entropy 
D)  work; energy 
A)  exergonic; spontaneous 
B)  exergonic; endergonic 
C)  free energy; entropy 
D)  work; energy

Question 18

Biological systems use free energy based on empirical data that all organisms require a constant energy input. The first law of thermodynamics states that energy can be neither created nor destroyed. For living organisms, which of the following statements is an important consequence of this first law?

Accepted Answer

A)  The energy content of an organism is constant except for when its cells are dividing. 
B)  The organism must ultimately obtain all the necessary energy for life from its environment. 
C)  The entropy of an organism decreases with time as the organism grows in complexity. 
D)  Organisms are unable to transform energy from the different states in which it can exist. 
A)  The energy content of an organism is constant except for when its cells are dividing. 
B)  The organism must ultimately obtain all the necessary energy for life from its environment. 
C)  The entropy of an organism decreases with time as the organism grows in complexity. 
D)  Organisms are unable to transform energy from the different states in which it can exist.

Question 19

-The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following terms best describes the forward reaction in the figure?

Accepted Answer

A)  endergonic, ∆G > 0 
B)  exergonic, ∆G  0 
A)  endergonic, ∆G > 0 
B)  exergonic, ∆G  0

Question 20

HIV is the virus that causes AIDS. In the mid-1990s, researchers discovered an enzyme in HIV called protease. Once the enzyme's structure was known, researchers began looking for drugs that would fit into the active site and block it. If this strategy for stopping HIV infections were successful, it would be an example of what phenomenon?

Accepted Answer

A)  noncompetitive inhibition 
B)  denaturation 
C)  allosteric regulation 
D)  competitive inhibition 
A)  noncompetitive inhibition 
B)  denaturation 
C)  allosteric regulation 
D)  competitive inhibition

Exam 8: An Introduction to Metabolism

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

In addition to activating or inhibiting enzymes through allosteric regulation, what other means does a cell use to control enzymatic activity?

Most cells cannot harness heat to perform work because

Which of the following is true when comparing an uncatalysed reaction to the same reaction with a catalyst?

If an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur?

Which of the following metabolic processes can occur without a net influx of energy from some other process?

Which of the following is a primary function of the active site of an enzyme?

Which of the following molecules is most similar in structure to ATP?

If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to

Which of the following statements is true for a system at chemical equilibrium?

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

Most cells cannot harness heat to perform work because ________.

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

Which of the following statements describes a central role that ATP plays in cellular metabolism?

A decrease in entropy is associated with which type of reaction?

Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as ________ is to ________.

-The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following terms best describes the forward reaction in the figure?

Evolution, the Themes of Biology, and Scientific Inquiry

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Viruses

Dna Tools and Biotechnology

Genomes and Their Evolution

Descent With Modification: a Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonised Land

Plant Diversity Ii: the Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Vascular Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signalling

Nervous Systems

Sensory and Motor Mechanisms

Filters

Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as is to .