Question 1

Which of the following lowers the activation energy of a biochemical reaction?

Accepted Answer

A)  High concentration of products 
B)  Presence of a catalyst 
C)  High temperature 
D)  Low concentration of reactants 
E)  Altering pH to 7 
A)  High concentration of products 
B)  Presence of a catalyst 
C)  High temperature 
D)  Low concentration of reactants 
E)  Altering pH to 7

Question 2

This figure shows the metabolism of glucose and oxygen to CO2 and H2O. From what molecule do the carbon in CO2 and the hydrogen in H2O come from?

Accepted Answer

A)  Glucose 
B)  O2 
C)  The catalyst 
D)  The product 
A)  Glucose 
B)  O2 
C)  The catalyst 
D)  The product

Question 3

What is the ultimate source of energy for almost all forms of life on Earth?

Accepted Answer

A)  Thermal energy 
B)  Solar energy 
C)  Nuclear energy 
D)  Chemical energy 
E)  Heat energy 
A)  Thermal energy 
B)  Solar energy 
C)  Nuclear energy 
D)  Chemical energy 
E)  Heat energy

Question 4

Explain how enzymes decrease the activation energy required for biological processes in our bodies.

Accepted Answer

Enzymes decrease the activatio

Question 5

Each of the following requires 12 carbon atoms. Which of the arrangements of carbon atoms has the greatest entropy?

Accepted Answer

A)  1 molecule of the disaccharide maltose, C12H22O11 
B)  4 molecules of the monosaccharide pyruvate, C3H4O3 
C)  12 molecules of carbon dioxide, CO2 
D)  2 molecules of the monosaccharide glucose, C6H12O6 
A)  1 molecule of the disaccharide maltose, C12H22O11 
B)  4 molecules of the monosaccharide pyruvate, C3H4O3 
C)  12 molecules of carbon dioxide, CO2 
D)  2 molecules of the monosaccharide glucose, C6H12O6

Question 6

Which of the enzymes shown in the figure is active in the stomach of the human digestive tract?

Accepted Answer

The answer of Which of the enzymes shown in the...

Question 7

Imagine that you are conducting an experiment on an enzyme known as sucrase. This enzyme is synthesized and used by yeast cells to break down the disaccharide sucrose (table sugar) into the monosaccharides glucose and fructose. You decide to conduct an experiment to test whether the sucrase enzyme can break down the artificial sweetener sucralose. Sucralose (a ʺchlorinatedʺ carbohydrate) has some chemical similarity to sucrose, but is different in that three of its hydroxyl groups are missing and replaced with chlorine atoms instead. Based on the details provided in this scenario, do you think the sucrase enzyme will be able to interact with sucralose?

Accepted Answer

A)  No; sucralose is an ion and not a true carbohydrate. 
B)  No; all enzymes are highly specific and can react with only a specific substrate. 
C)  Yes; enzymes such as sucrase are not specific for their substrate. 
D)  Yes; the enzymes in human cells can interact with artificial sweeteners as if they were sugars. 
A)  No; sucralose is an ion and not a true carbohydrate. 
B)  No; all enzymes are highly specific and can react with only a specific substrate. 
C)  Yes; enzymes such as sucrase are not specific for their substrate. 
D)  Yes; the enzymes in human cells can interact with artificial sweeteners as if they were sugars.

Question 8

All of the following statements are true of the first law of thermodynamics EXCEPT

Accepted Answer

A)  the amount of useful energy decreases when energy is converted from one form to another. 
B)  the total amount of energy within a closed system remains the same. 
C)  one form of energy may be converted to a different form of energy. 
D)  the first law of thermodynamics is often called the law of the conservation of energy. 
A)  the amount of useful energy decreases when energy is converted from one form to another. 
B)  the total amount of energy within a closed system remains the same. 
C)  one form of energy may be converted to a different form of energy. 
D)  the first law of thermodynamics is often called the law of the conservation of energy.

Question 9

Which statement best describes the relationship between an enzyme and a reactant?

Accepted Answer

A)  One enzyme typically has many reactants with which it will associate. 
B)  The enzyme and the reactant molecule are both permanently changed. 
C)  The resultant product and the enzyme are permanently bonded together. 
D)  The relationship is temporary. 
E)  Covalent chemical bonds stabilize the relationship. 
A)  One enzyme typically has many reactants with which it will associate. 
B)  The enzyme and the reactant molecule are both permanently changed. 
C)  The resultant product and the enzyme are permanently bonded together. 
D)  The relationship is temporary. 
E)  Covalent chemical bonds stabilize the relationship.

Question 10

The most common energy carrier molecule in living organisms is

Accepted Answer

A)  glucose. 
B)  NADPH. 
C)  DNA. 
D)  ADP. 
E)  ATP. 
A)  glucose. 
B)  NADPH. 
C)  DNA. 
D)  ADP. 
E)  ATP.

Question 11

Triclosan is a broad-spectrum antibacterial agent used in many household products. It is structurally similar to polychlorobiphenylol, a substrate that binds to the active site of the enzyme sulfotransferase. Based on these facts, you can conclude that triclosan most likely

Accepted Answer

A)  lowers the activation energy of chemical reactions. 
B)  acts as a noncompetitive inhibitor. 
C)  is a competitive inhibitor. 
D)  functions as an enzyme when sulfotransferase is absent. 
A)  lowers the activation energy of chemical reactions. 
B)  acts as a noncompetitive inhibitor. 
C)  is a competitive inhibitor. 
D)  functions as an enzyme when sulfotransferase is absent.

Question 12

To say that an enzyme has been denatured means that

Accepted Answer

A)  the enzyme is working at its maximal rate. 
B)  the enzyme is working at an optimal temperature. 
C)  an inhibitor has bound the enzyme at the active site. 
D)  its three-dimensional structure has changed and the enzyme can no longer function properly. 
A)  the enzyme is working at its maximal rate. 
B)  the enzyme is working at an optimal temperature. 
C)  an inhibitor has bound the enzyme at the active site. 
D)  its three-dimensional structure has changed and the enzyme can no longer function properly.

Question 13

Which of the following statements regarding enzymes is FALSE?

Accepted Answer

A)  The activity of enzymes can be regulated by factors in their environment. 
B)  Enzymes are highly specific for the molecules to which they attach. 
C)  Enzymes provide energy for the reactions they catalyze. 
D)  Enzymes are proteins that function as biological catalysts. 
E)  An enzyme may be used many times for the same specific reaction. 
A)  The activity of enzymes can be regulated by factors in their environment. 
B)  Enzymes are highly specific for the molecules to which they attach. 
C)  Enzymes provide energy for the reactions they catalyze. 
D)  Enzymes are proteins that function as biological catalysts. 
E)  An enzyme may be used many times for the same specific reaction.

Question 14

Coupled reactions are important components of human physiology. Describe an example of a coupled reaction in the human body.

Accepted Answer

A coupled reaction is when an exergonic

Question 15

Describe the molecular difference between ATP and ADP.

Accepted Answer

Both ATP and ADP contain an ad

Question 16

How is your body able to work against the effects of entropy?

Accepted Answer

A)  Sunbathing 
B)  Regular work 
C)  Eating a balanced diet and proper nourishment 
D)  Regular exercise 
A)  Sunbathing 
B)  Regular work 
C)  Eating a balanced diet and proper nourishment 
D)  Regular exercise

Question 17

Energy that is not converted to useful energy is usually given off as

Accepted Answer

A)  entropy. 
B)  light. 
C)  radioactivity. 
D)  heat. 
E)  electricity. 
A)  entropy. 
B)  light. 
C)  radioactivity. 
D)  heat. 
E)  electricity.

Question 18

The molecule________ is the major energy carrier in cells.

Accepted Answer

The answer of The molecule________ is the major energy carrier...

Question 19

Which of the following has the greatest amount of kinetic energy?

Accepted Answer

A)  A hot car engine 
B)  A moving car 
C)  A tank of gasoline 
D)  The cool air surrounding the car engine 
E)  An unlit firecracker 
A)  A hot car engine 
B)  A moving car 
C)  A tank of gasoline 
D)  The cool air surrounding the car engine 
E)  An unlit firecracker

Question 20

The reactant in an enzyme-catalyzed reaction is the

Accepted Answer

A)  activation energy. 
B)  allosteric inhibitor. 
C)  active site. 
D)  product. 
E)  substrate. 
A)  activation energy. 
B)  allosteric inhibitor. 
C)  active site. 
D)  product. 
E)  substrate.

Exam 6: Energy Flow in the Life of a Cell

Which of the following lowers the activation energy of a biochemical reaction?

This figure shows the metabolism of glucose and oxygen to CO2 and H2O. From what molecule do the carbon in CO2 and the hydrogen in H2O come from?

What is the ultimate source of energy for almost all forms of life on Earth?

Explain how enzymes decrease the activation energy required for biological processes in our bodies.

Each of the following requires 12 carbon atoms. Which of the arrangements of carbon atoms has the greatest entropy?

Which of the enzymes shown in the figure is active in the stomach of the human digestive tract?

All of the following statements are true of the first law of thermodynamics EXCEPT

Which statement best describes the relationship between an enzyme and a reactant?

The most common energy carrier molecule in living organisms is

Triclosan is a broad-spectrum antibacterial agent used in many household products. It is structurally similar to polychlorobiphenylol, a substrate that binds to the active site of the enzyme sulfotransferase. Based on these facts, you can conclude that triclosan most likely

To say that an enzyme has been denatured means that

Which of the following statements regarding enzymes is FALSE?

Coupled reactions are important components of human physiology. Describe an example of a coupled reaction in the human body.

Describe the molecular difference between ATP and ADP.

How is your body able to work against the effects of entropy?

Energy that is not converted to useful energy is usually given off as

The molecule________ is the major energy carrier in cells.

Which of the following has the greatest amount of kinetic energy?

The reactant in an enzyme-catalyzed reaction is the

An Introduction to Life on Earth

Atoms, Molecules, and Life

Biological Molecules

Cell Structure and Function

Cell Membrane Structure and Function

Capturing Solar Energy: Photosynthesis

Harvesting Energy: Glycolysis and Cellular Respiration

Cellular Reproduction

Meiosis: the Basis of Sexual Reproduction

Patterns of Inheritance

DNA: The Molecule of Heredity

Gene Expression and Regulation

Biotechnology

Principles of Evolution

How Populations Evolve

The Origin of Species

The History of Life

Systematics: Seeking Order Amid Diversity

The Diversity of Prokaryotes and Viruses

The Diversity of Protists

The Diversity of Plants

The Diversity of Fungi

Animal Diversity I: Invertebrates

Animal Diversity Ii: Vertebrates

Animal Behavior

Population Growth and Regulation

Community Interactions

Energy Flow and Nutrient Cycling in Ecosystems

Earths Diverse Ecosystems

Conserving Earths Biodiversity

Homeostasis and the Organization of the Animal Body

Circulation

Respiration

Nutrition and Digestion

The Urinary System

Defenses Against Disease

Chemical Control of the Animal Body: the Endocrine System

The Nervous System

The Senses

Action and Support: the Muscles and Skeleton

Animal Reproduction

Animal Development

Plant Anatomy and Nutrient Transport

Plant Reproduction and Development

Plant Responses to the Environment

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This figure shows the metabolism of glucose and oxygen to CO₂ and H₂O. From what molecule do the carbon in CO₂ and the hydrogen in H₂O come from?