Deck 20: The Generation of Biochemical Energy

Question 1

A metabolic pathway that can be illustrated as A → B → C → D is said to be a(an)________ pathway.

A)anabolic
B)catabolic
C)cyclic
D)linear
E)spiral

Answer 1

linear

Question 2

The sum of all the biochemical reactions occurring in an organism is

A)anabolism.
B)catabolism.
C)digestion.
D)metabolism.
E)respiration.

Answer 2

metabolism.

Question 3

The cellular organelle that is responsible for most cellular catabolic redox reactions is the

A)mitochondria
B)chloroplast
C)peroxisome
D)ribosome

Answer 3

mitochondria

Question 4

Photosynthesis is an ________ process because the free energy of the products is ________ the free energy of the reactants.

A)endergonic; greater than
B)exergonic; greater than
C)endergonic; less than
D)exergonic; less than
E)equilibrium; the same as

Question 5

A metabolic pathway in which a molecule is progressively built up by repeated interaction with the same set of enzymes is a(an)________ pathway.

A)anabolic
B)catabolic
C)cyclic
D)linear
E)spiral

Question 6

Exergonic reactions are those that have a ________ value of ΔG and ________ spontaneous.

A)positive; are
B)positive; are not
C)negative; are
D)negative; are not
E)none of the above

Question 7

Exergonic reactions are those that are ________ and that ________ liberate free energy.

A)spontaneous; do
B)nonspontaneous; do
C)spontaneous; do not
D)nonspontaneous; do not
E)none of the above

Question 8

The biochemical process in which simple molecules are combined to make larger ones and energy is consumed is referred to as

A)anabolism.
B)catabolism.
C)digestion.
D)metabolism.
E)respiration.

Question 9

The mitochondria are the location where ________ takes place and most ________ is produced.

A)citric acid cycle; ATP
B)digestion; acetyl coenzyme A
C)digestion; ATP
D)citric acid cycle; acetyl coenzyme A
E)digestion; fatty acid

Question 10

The biochemical process in which complex molecules are broken down into simpler ones and energy is released is referred to as

A)anabolism.
B)catabolism.
C)digestion.
D)metabolism.
E)respiration.

Question 11

The abbreviation ATP stands for

A)adenine + three phosphates.
B)adenosine triphosphate.
C)adenosine tetraphosphate.
D)anabolic triple phosphate.
E)alanine triphosphate.

Question 12

Endergonic reactions are those that are ________ and that ________ liberate free energy.

A)spontaneous; do
B)nonspontaneous; do
C)spontaneous; do not
D)nonspontaneous; do not
E)none of the above

Question 13

The contents of a cell found between the nuclear membrane and the cell membrane are called the

A)cytosol.
B)mitochondria.
C)mitochondrial matrix.
D)organelles.
E)cytoplasm.

Question 14

All of the following are specific requirements for energy in biochemical processes except

A)stored energy must be in a form that is chemically accessible.
B)release of energy from storage must occur at a carefully controlled rate.
C)release of energy from food must occur gradually.
D)energy needed for unfavorable reactions must be available in the form of heat.
E)the correct amount of heat must be released from biochemical reactions to maintain body temperature.

Question 15

The process by which the cell produces ATP in the mitochondria is called

A)oxidative phosphorylation
B)hydrolysis
C)substrate-level phosphorylation
D)electron transport

Question 16

The enzymes of the oxidative phosphorylation system are located in the

A)cytosol.
B)nucleus.
C)matrix of the mitochondria.
D)cristae of the mitochondria.
E)endoplasmic reticulum.

Question 17

Metabolism is composed of which process(es)?

A)anabolism
B)catabolism
C)oncologism
D)both A and B
E)both B and C

Question 18

Endergonic reactions are those that have a ________ value of ΔG and ________ spontaneous.

A)positive; are
B)positive; are not
C)negative; are
D)negative; are not
E)none of the above

Question 19

The ultimate source of energy for all but a very few biochemical reactions is

A)hydrocarbons.
B)carbohydrates.
C)lipids.
D)the sun.
E)ATP.

Question 20

The cellular organelle associated with energy production is the

A)nucleus.
B)mitochondrion.
C)Golgi apparatus.
D)endoplasmic reticulum.
E)lysosome.

Question 21

Which of the following is not true of NAD⁺ and FAD?

A)Energy in the reduced state is used to produce ATP.
B)They both contain two nucleosides.
C)They donate electrons to the electron transport system.
D)The reduced form of FAD has more energy than the reduced form of NAD⁺.

Question 22

Which group of compounds includes only low-energy molecules?

A)ATP,acetyl-SCoA,NADH,FADH₂
B)ADP,acetyl-SCoA,NAD⁺,FAD
C)ATP,CO₂,NADH,FADH₂
D)ADP,CO₂,NADH,FADH₂
E)ADP,CO₂,NAD⁺,FAD

Question 23

Which of the following is common to the structures of NAD⁺,and FAD?

A)nicotinic acid
B)nicotinamide
C)ATP
D)ADP
E)AMP

Question 24

The reaction in which ATP is converted to ADP with release of 7.3 kcal is a(an)________ reaction.

A)hydrolysis
B)reduction
C)combustion
D)oxidation
E)polymerization

Question 25

Which of the following does not undergo oxidation-reduction reactions?

A)ATP
B)NADH
C)NADPH
D)FAD

Question 26

ATP is the molecule most often used for energy transport because

A)a relatively large amount of energy is released upon hydrolysis of its two phosphoric anhydride bonds.
B)its hydrolysis releases an intermediate amount of energy and is relatively slow except in the presence of the appropriate enzymes.
C)it can only be produced in the citric acid cycle.
D)it can only be produced as a result of reactions in the electron transport chain.
E)its production from ADP is endergonic.

Question 27

The common molecule produced from all foods at the second stage of catabolism is

A)ADP.
B)acetyl-SCoA.
C)glucose.
D)citric acid.
E)carbon dioxide.

Question 28

Which group of compounds includes only high-energy molecules?

A)ATP,acetyl-SCoA,NADH,FADH₂
B)ADP,acetyl-SCoA,NAD⁺,FAD
C)ATP,CO₂,NADH,FADH₂
D)ADP,CO₂,NADH,FADH₂
E)ATP,CO₂,NAD⁺,FAD

Question 29

Which statement is true concerning the relationship between FAD and FADH₂?

A)FADH₂ is the oxidized form of FAD.
B)FADH₂ is the reduced form of FAD.
C)The conversion of FADH₂ to FAD is an acid/base reaction.
D)The conversion of FADH₂ to FAD is a cyclization reaction.
E)none of the above

Question 30

List and discuss the reasons that ATP is so useful as a biochemical energy transport molecule.

Question 31

Which sequence illustrates the order of the steps from food to biochemically useful energy?

A)digestion; citric acid cycle; ATP production; acetyl-SCoA production
B)digestion; citric acid cycle; acetyl-SCoA production; ATP production
C)citric acid cycle; digestion; acetyl-SCoA production; ATP production
D)digestion; acetyl-SCoA production; citric acid cycle; ATP production
E)digestion; acetyl-SCoA production; ATP production; citric acid cycle

Question 32

Which statement concerning coenzymes and redox reactions is incorrect?

A)Oxidation can be considered as loss of hydrogen or gain of oxygen.
B)Reduction can be considered as gain of hydrogen or loss of oxygen.
C)NAD⁺ is the oxidized form of NADH.
D)An oxidation reaction cannot occur unless a reduction reaction also occurs.
E)FAD is the reduced form of FADH₂.

Question 33

The purpose of coupling two biochemical reactions is to

A)lower the activation energies of both reactions.
B)convert an endergonic reaction to an exergonic one.
C)convert an exergonic reaction to an endergonic one.
D)use an endergonic reaction to drive an exergonic reaction.
E)use an exergonic reaction to drive an endergonic reaction.

Question 34

Which statement is true concerning the relationship between NAD⁺ and NADH?

A)NAD⁺ is the oxidized form of NADH.
B)NAD⁺ is the reduced form of NADH.
C)The conversion of NAD⁺ to NADH is an acid/base reaction.
D)The conversion of NAD⁺ to NADH is a cyclization reaction.
E)none of the above

Question 35

Which of the following reactions is the least energetic?

A)ATP + H₂O → ADP + P_i
B)ATP + H₂O → AMP + PP_i
C)ADP + H₂O → AMP + P_i
D)AMP + H₂O → Adenosine + P_i
E)All give off the same amount of energy.

Question 36

A metabolic pathway in which a series of steps,each using different enzymes,regenerates one of the early reactants,is a(an)________ pathway.

A)anabolic
B)catabolic
C)cyclic
D)linear
E)spiral

Question 37

A cyclic metabolic sequence can best be described as one in which

A)the product of the first reaction is the starting material for the next reaction,and so on.
B)a series of reactions regenerates the initial reactant.
C)the various reactions have virtually no connection to one another.
D)the same set of enzymes progressively builds up a molecule.
E)the same set of enzymes catalyses the same reaction in both the forward and reverse directions.

Question 38

All of the following are energy strategies used in biochemical reactions except

A)ATP is produced as a means of transferring energy.
B)exergonic reactions are used to drive unfavorable reactions.
C)chemical reactions occur in pairs in order to change the value of ΔG for one of the reactions.
D)coenzymes which can exist in oxidized or reduced forms are used to transfer electrons.
E)ADP is transformed into a higher energy molecule when coupled to an exergonic reaction.

Question 39

A spiral metabolic sequence can best be described as one in which

A)the product of the first reaction is the starting material for the next reaction,and so on.
B)a series of reactions regenerates the initial reactant.
C)the various reactions have virtually no connection to one another.
D)the same set of enzymes progressively builds up or breaks down a molecule.
E)the same set of enzymes catalyses the same reaction in both the forward and reverse directions.

Question 40

In a pair of coupled reactions,if the favorable reaction releases more energy than the amount required by the unfavorable reaction,the excess energy is

A)reabsorbed by the favorable reaction to be used later.
B)released as heat and used to maintain body temperature.
C)used by the unfavorable reaction to create more products than normally expected.
D)converted to high energy ATP.
E)used to produce reduced coenzymes.

Question 41

The metal that acts as an electron carrier in the cytochromes in the electron transport chain is

A)magnesium.
B)chromium.
C)iron.
D)cobalt.
E)hydrogen.

Question 42

Every turn of the citric acid cycle directly produces ________ molecule(s)of ATP.

A)zero
B)one
C)two
D)three
E)six

Question 43

All of the following chemicals except ________ provide protection against potentially harmful oxygen species.

A)beta-carotene
B)catalase
C)hydrogen peroxide
D)vitamin C
E)vitamin E

Question 44

The formation of acetyl coenzyme A is an example of a(an)________ reaction.

A)esterification
B)redox
C)addition
D)acid / base
E)elimination

Question 45

In many catabolic processes the principal product is ________ to be processed in the ________.

A)acetyl coenzyme A,citric acid cycle
B)acetyl coenzyme A,electron transport chain
C)ATP,electron transport chain
D)ATP,citric acid cycle
E)ADP,electron transport chain

Question 46

All of the following chemicals are involved in the citric acid cycle except

A)acetyl-SCoA.
B)isocitrate.
C)succinate.
D)malate.
E)ascorbate.

Question 47

In steps 5-8 of the citric acid cycle,the high-energy molecules ________,________,and ________ are produced,and ________ is regenerated to begin another turn of the cycle.

A)GDP; FADH₂; NADH/H⁺; oxaloacetate
B)GTP; FADH₂; NADH/H⁺; oxaloacetate
C)ATP; FADH₂; NADH/H⁺; citrate
D)ADP; FAD; NAD⁺; oxaloacetate
E)GDP; FADH₂; NADH/H⁺; isocitrate

Question 48

In steps 3 and 4 of the citric acid cycle,successive oxidations produce ________ as a waste product and the four-carbon carrier ________.

A)CO₂; oxaloacetate
B)ADP; oxaloacetate
C)CO₂; succinyl-SCoA
D)ADP; succinyl-SCoA
E)CO₂; malate

Question 49

Which of the following statements about free radicals is incorrect?

A)They are a by-product of oxygen-consuming redox reactions.
B)Their unpaired electron makes them extremely reactive.
C)They can disrupt covalent bonds in biomolecules.
D)B vitamins provide protection from their harmful effects.
E)Superoxide catalase is one of the specific enzymes that can provide protection from their harmful effects.

Question 50

The process of converting ADP to ATP in the mitochondrion takes place by a process known as

A)oxidative phosphorylation.
B)chemiosmosis.
C)respiration.
D)reductive phosphorylation
E)chemiosmotic phosphorylation.

Question 51

The fourth stage of metabolism,in which the high energy molecules from stage three are oxidized to produce ATP is referred to as

A)active transport.
B)reductive phosphorylation.
C)the electron transport chain.
D)the Krebs cycle.
E)glycolysis.

Question 52

Match the following.
catabolism

A)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
B)metabolic processes that consume energy in order to build molecules
C)the universal energy currency of the cell; a molecule used to transfer energy
D)the molecule produced from digestion products in the second stage of catabolism
E)metabolic processes that break down large molecules,thereby releasing energy
F)the stage of catabolism in which acetyle-SCoA is oxidized to produce ATP,reduced coenzymes,and CO₂
G)a molecule that can be phosphorylated as a means of temporarily storing energy
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 53

Harmful byproducts of biochemical oxidation include

A)superoxide dismutase and catalase.
B)vitamins A,C,and E.
C)superoxide ions and hydroxyl free radicals.
D)ATP.
E)coenzyme Q.

Question 54

All of the following molecules are directly involved in the electron transport chain except

A)coenzyme Q.
B)ADP.
C)cytochrome c.
D)acetyl-SCoA.
E)H₂O.

Question 55

Match the following.
anabolism

A)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
B)metabolic processes that consume energy in order to build molecules
C)the universal energy currency of the cell; a molecule used to transfer energy
D)the molecule produced from digestion products in the second stage of catabolism
E)metabolic processes that break down large molecules,thereby releasing energy
F)the stage of catabolism in which acetyle-SCoA is oxidized to produce ATP,reduced coenzymes,and CO₂
G)a molecule that can be phosphorylated as a means of temporarily storing energy
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 56

The driving force which provides the energy for synthesis of ATP in the fourth stage of metabolism is

A)the exergonic conversion of ADP to ATP.
B)the energy difference between reduced carbon atoms and oxidized carbon atoms.
C)the concentration gradient of hydrogen ions between the two sides of the inner mitochondrial membrane.
D)the concentration difference in oxygen between the cell and the intercellular fluid.
E)none of the above

Question 57

The proton translocating ATP synthase complex is located in the

A)cytosol.
B)outer membrane of the mitochondria.
C)inner membrane of the mitochondria.
D)matrix.
E)intermembrane space.

Question 58

After O₂ has been reduced in the electron transport chain,the oxygen atoms are part of what molecules?

A)ATP
B)water
C)carbon dioxide
D)acetate
E)acetyl-SCoA

Question 59

In addition to producing ATP,the citric acid cycle produces ________ as high energy molecules and ________ as its major chemical waste product.

A)oxidized coenzymes; H₂O
B)oxidized coenzymes; CO₂
C)reduced coenzymes; H₂O
D)reduced coenzymes; CO₂
E)ADP; O₂

Question 60

In the first step of the citric acid cycle,acetyl-SCoA reacts with ________ to produce ________,which is isomerized to ________ in the second step.

A)succinate; fumarate; malate
B)succinate; malate; fumarate
C)oxaloacetate; isocitrate; citrate
D)oxaloacetate; citrate; isocitrate
E)aconitase; isocitrate; citrate

Question 61

Match the following.
digestion

A)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
B)metabolic processes that consume energy in order to build molecules
C)the universal energy currency of the cell; a molecule used to transfer energy
D)the molecule produced from digestion products in the second stage of catabolism
E)metabolic processes that break down large molecules,thereby releasing energy
F)the stage of catabolism in which acetyle-SCoA is oxidized to produce ATP,reduced coenzymes,and CO₂
G)a molecule that can be phosphorylated as a means of temporarily storing energy
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 62

Match the following.
acetyl-SCoA

A)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
B)metabolic processes that consume energy in order to build molecules
C)the universal energy currency of the cell; a molecule used to transfer energy
D)the molecule produced from digestion products in the second stage of catabolism
E)metabolic processes that break down large molecules,thereby releasing energy
F)the stage of catabolism in which acetyle-SCoA is oxidized to produce ATP,reduced coenzymes,and CO₂
G)a molecule that can be phosphorylated as a means of temporarily storing energy
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 63

Match the following.
electron transport chain

A)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
B)metabolic processes that consume energy in order to build molecules
C)the universal energy currency of the cell; a molecule used to transfer energy
D)the molecule produced from digestion products in the second stage of catabolism
E)metabolic processes that break down large molecules,thereby releasing energy
F)the stage of catabolism in which acetyle-SCoA is oxidized to produce ATP,reduced coenzymes,and CO₂
G)a molecule that can be phosphorylated as a means of temporarily storing energy
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 64

Match the following.
ATP

A)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
B)metabolic processes that consume energy in order to build molecules
C)the universal energy currency of the cell; a molecule used to transfer energy
D)the molecule produced from digestion products in the second stage of catabolism
E)metabolic processes that break down large molecules,thereby releasing energy
F)the stage of catabolism in which acetyle-SCoA is oxidized to produce ATP,reduced coenzymes,and CO₂
G)a molecule that can be phosphorylated as a means of temporarily storing energy
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 65

Match the following.
ADP

A)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
B)metabolic processes that consume energy in order to build molecules
C)the universal energy currency of the cell; a molecule used to transfer energy
D)the molecule produced from digestion products in the second stage of catabolism
E)metabolic processes that break down large molecules,thereby releasing energy
F)the stage of catabolism in which acetyle-SCoA is oxidized to produce ATP,reduced coenzymes,and CO₂
G)a molecule that can be phosphorylated as a means of temporarily storing energy
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP

Question 66

Match the following.
citric acid cycle

A)the stage of catabolism in which complex food molecules are broken down into simpler substances for transport and/or further reaction
B)metabolic processes that consume energy in order to build molecules
C)the universal energy currency of the cell; a molecule used to transfer energy
D)the molecule produced from digestion products in the second stage of catabolism
E)metabolic processes that break down large molecules,thereby releasing energy
F)the stage of catabolism in which acetyle-SCoA is oxidized to produce ATP,reduced coenzymes,and CO₂
G)a molecule that can be phosphorylated as a means of temporarily storing energy
H)the stage of catabolism in which the energy stored in reduced coenzymes is converted to ATP