Question 1

Whenever energy is transformed, there is always an increase in the

Accepted Answer

A) free energy of the system. 
B) free energy of the universe. 
C) entropy of the system. 
D) entropy of the universe. 
E) enthalpy of the universe. 
A) free energy of the system. 
B) free energy of the universe. 
C) entropy of the system. 
D) entropy of the universe. 
E) enthalpy of the universe.

Question 2

Which of the following statements is true concerning catabolic pathways?

Accepted Answer

A) They combine molecules into more energy-rich molecules. 
B) They supply energy, primarily in the form of ATP, for the cell's work. 
C) They are endergonic. 
D) They are spontaneous and do not need enzyme catalysis. 
E) They build up complex molecules such as protein from simpler compounds. 
A) They combine molecules into more energy-rich molecules. 
B) They supply energy, primarily in the form of ATP, for the cell's work. 
C) They are endergonic. 
D) They are spontaneous and do not need enzyme catalysis. 
E) They build up complex molecules such as protein from simpler compounds.

Question 3

The following questions are based on the reaction A + B ↔ C + D shown in the figure below.
  
-Which of the following represents the difference between the free-energy content of the reaction and the free-energy content of the products in the figure above?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) e 
A) a 
B) b 
C) c 
D) d 
E) e

Question 4

When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any)in the cell?

Accepted Answer

A) The phosphate is released as an excretory waste. 
B) The phosphate can only be used to regenerate more ATP. 
C) The phosphate can be added to water and excreted as a liquid. 
D) The phosphate may be incorporated into any molecule that contains phosphate. 
E) It enters the nucleus to affect gene expression. 
A) The phosphate is released as an excretory waste. 
B) The phosphate can only be used to regenerate more ATP. 
C) The phosphate can be added to water and excreted as a liquid. 
D) The phosphate may be incorporated into any molecule that contains phosphate. 
E) It enters the nucleus to affect gene expression.

Question 5

Use the following figure to answer the questions below.
  
-How do cells use the ATP cycle shown in the figure?

Accepted Answer

A) Cells use the cycle to recycle ADP and phosphate. 
B) Cells use the cycle to recycle energy released by ATP hydrolysis. 
C) Cells use the cycle to recycle ADP, phosphate, and the energy released by ATP hydrolysis. 
D) Cells use the cycle to generate or consume water molecules as needed. 
E) Cells use the cycle primarily to generate heat. 
A) Cells use the cycle to recycle ADP and phosphate. 
B) Cells use the cycle to recycle energy released by ATP hydrolysis. 
C) Cells use the cycle to recycle ADP, phosphate, and the energy released by ATP hydrolysis. 
D) Cells use the cycle to generate or consume water molecules as needed. 
E) Cells use the cycle primarily to generate heat.

Question 6

Use the following information to answer the questions below.
A series of enzymes catalyze the reaction 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.
-With respect to the enzyme that converts X to Y, substance A functions as

Accepted Answer

A) a coenzyme. 
B) an allosteric inhibitor. 
C) the substrate. 
D) an intermediate. 
E) a competitive inhibitor. 
A) a coenzyme. 
B) an allosteric inhibitor. 
C) the substrate. 
D) an intermediate. 
E) a competitive inhibitor.

Question 7

The following questions are based on the reaction A + B ↔ C + D shown in the figure below.
  
-Which of the following in the figure above would be the same in either an enzyme-catalyzed or a noncatalyzed reaction?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) e 
A) a 
B) b 
C) c 
D) d 
E) e

Question 8

An important group of peripheral membrane proteins are enzymes such as the phospholipases that cleave the head groups of phospholipids. What properties must these enzymes exhibit?

Accepted Answer

A) resistance to degradation 
B) independence from cofactor interaction 
C) water solubility 
D) lipid solubility 
E) membrane-spanning domains 
A) resistance to degradation 
B) independence from cofactor interaction 
C) water solubility 
D) lipid solubility 
E) membrane-spanning domains

Question 9

Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?

Accepted Answer

A) catalysis 
B) metabolism 
C) anabolism 
D) dehydration 
E) catabolism 
A) catalysis 
B) metabolism 
C) anabolism 
D) dehydration 
E) catabolism

Question 10

The following questions are based on the reaction A + B ↔ C + D shown in the figure below.
  
-Which of the following represents the ΔG of the reaction in the figure above?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) e 
A) a 
B) b 
C) c 
D) d 
E) e

Question 11

When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows

Accepted Answer

A) +ΔG, +ΔH, +ΔS. 
B) +ΔG, +ΔH, -ΔS. 
C) +ΔG, -ΔH, -ΔS. 
D) -ΔG, +ΔH, +ΔS. 
E) -ΔG, -ΔH, -ΔS. 
A) +ΔG, +ΔH, +ΔS. 
B) +ΔG, +ΔH, -ΔS. 
C) +ΔG, -ΔH, -ΔS. 
D) -ΔG, +ΔH, +ΔS. 
E) -ΔG, -ΔH, -ΔS.

Question 12

Use the following figure to answer the questions below.
   
Rate of an enzyme-catalyzed reaction as a function of varying reactant
concentration, with the concentration of enzyme constant.
-In the figure, why does the reaction rate plateau at higher reactant concentrations?

Accepted Answer

A) Feedback inhibition by product occurs at high reactant concentrations. 
B) Most enzyme molecules are occupied by substrate at high reactant concentrations. 
C) The reaction nears equilibrium at high reactant concentrations. 
D) The activation energy for the reaction increases with reactant concentration. 
E) The rate of the reverse reaction increases with reactant concentration. 
A) Feedback inhibition by product occurs at high reactant concentrations. 
B) Most enzyme molecules are occupied by substrate at high reactant concentrations. 
C) The reaction nears equilibrium at high reactant concentrations. 
D) The activation energy for the reaction increases with reactant concentration. 
E) The rate of the reverse reaction increases with reactant concentration.

Question 13

The following questions are based on the reaction A + B ↔ C + D shown in the figure below.
  
-Which of the following represents the activation energy needed for the enzyme-catalyzed reverse reaction, C + D → A + B, in the figure above?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) e 
A) a 
B) b 
C) c 
D) d 
E) e

Question 14

Which of the following is true for all exergonic reactions?

Accepted Answer

A) The products have more total energy than the reactants. 
B) The reaction proceeds with a net release of free energy. 
C) The reaction goes only in a forward direction: all reactants will be converted to products, but no products will be converted to reactants. 
D) A net input of energy from the surroundings is required for the reactions to proceed. 
E) The reactions are rapid. 
A) The products have more total energy than the reactants. 
B) The reaction proceeds with a net release of free energy. 
C) The reaction goes only in a forward direction: all reactants will be converted to products, but no products will be converted to reactants. 
D) A net input of energy from the surroundings is required for the reactions to proceed. 
E) The reactions are rapid.

Question 15

Allosteric enzyme regulation is usually associated with

Accepted Answer

A) lack of cooperativity. 
B) feedback inhibition. 
C) activating activity. 
D) an enzyme with more than one subunit. 
E) the need for cofactors. 
A) lack of cooperativity. 
B) feedback inhibition. 
C) activating activity. 
D) an enzyme with more than one subunit. 
E) the need for cofactors.

Question 16

Use the following information to answer the questions below.
   
Activity of various enzymes at various temperatures (a) and at various pH (b).
-Which curve(s)on the graphs may represent the temperature and pH profiles of an enzyme taken from a bacterium that lives in a mildly alkaline hot springs at temperatures of 70°C or higher?

Accepted Answer

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

Question 17

Which of the following is an example of cooperativity?

Accepted Answer

A) the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway 
B) one enzyme in a metabolic pathway passing its product to act as a substrate for the next enzyme in the pathway 
C) a molecule binding at one unit of a tetramer, allowing faster binding at each of the other three 
D) the effect of increasing temperature on the rate of an enzymatic reaction 
E) binding of an ATP molecule along with one of the substrate molecules in an active site 
A) the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway 
B) one enzyme in a metabolic pathway passing its product to act as a substrate for the next enzyme in the pathway 
C) a molecule binding at one unit of a tetramer, allowing faster binding at each of the other three 
D) the effect of increasing temperature on the rate of an enzymatic reaction 
E) binding of an ATP molecule along with one of the substrate molecules in an active site

Question 18

A system at chemical equilibrium

Accepted Answer

A) consumes energy at a steady rate. 
B) releases energy at a steady rate. 
C) consumes or releases energy, depending on whether it is exergonic or endergonic. 
D) has zero kinetic energy. 
E) can do no work. 
A) consumes energy at a steady rate. 
B) releases energy at a steady rate. 
C) consumes or releases energy, depending on whether it is exergonic or endergonic. 
D) has zero kinetic energy. 
E) can do no work.

Question 19

During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a ∆G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the ∆G for the new reaction?

Accepted Answer

A) -40 kcal/mol 
B) -20 kcal/mol 
C) 0 kcal/mol 
D) +20 kcal/mol 
E) +40 kcal/mol 
A) -40 kcal/mol 
B) -20 kcal/mol 
C) 0 kcal/mol 
D) +20 kcal/mol 
E) +40 kcal/mol

Question 20

A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because

Accepted Answer

A) the starch solution has less free energy than the sugar solution. 
B) the hydrolysis of starch to sugar is endergonic. 
C) the activation energy barrier for this reaction cannot be surmounted. 
D) starch cannot be hydrolyzed in the presence of so much water. 
E) starch hydrolysis is nonspontaneous. 
A) the starch solution has less free energy than the sugar solution. 
B) the hydrolysis of starch to sugar is endergonic. 
C) the activation energy barrier for this reaction cannot be surmounted. 
D) starch cannot be hydrolyzed in the presence of so much water. 
E) starch hydrolysis is nonspontaneous.

Exam 8: An Introduction to Metabolism

Whenever energy is transformed, there is always an increase in the

Which of the following statements is true concerning catabolic pathways?

The following questions are based on the reaction A + B ↔ C + D shown in the figure below. -Which of the following represents the difference between the free-energy content of the reaction and the free-energy content of the products in the figure above?

When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any)in the cell?

Use the following figure to answer the questions below. -How do cells use the ATP cycle shown in the figure?

The following questions are based on the reaction A + B ↔ C + D shown in the figure below. -Which of the following in the figure above would be the same in either an enzyme-catalyzed or a noncatalyzed reaction?

An important group of peripheral membrane proteins are enzymes such as the phospholipases that cleave the head groups of phospholipids. What properties must these enzymes exhibit?

Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?

The following questions are based on the reaction A + B ↔ C + D shown in the figure below. -Which of the following represents the ΔG of the reaction in the figure above?

When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows

Use the following figure to answer the questions below. Rate of an enzyme-catalyzed reaction as a function of varying reactant concentration, with the concentration of enzyme constant. -In the figure, why does the reaction rate plateau at higher reactant concentrations?

The following questions are based on the reaction A + B ↔ C + D shown in the figure below. -Which of the following represents the activation energy needed for the enzyme-catalyzed reverse reaction, C + D → A + B, in the figure above?

Which of the following is true for all exergonic reactions?

Allosteric enzyme regulation is usually associated with

Which of the following is an example of cooperativity?

A system at chemical equilibrium

During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a ∆G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the ∆G for the new reaction?

A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because

Introduction: Evolution and Themes of Biology

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

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 Colonized 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

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

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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