Deck 25: Metabolism and Energetics

Question 1

The chemical equation that correctly summarizes the overall reaction in oxidative phosphorylation is

A)H₂ + O₂ → H₂O + O.
B)2 H₂ + O₂ → 2 H₂O.
C)3 H₂ + 2O₂ → 3 H₂O + 2 O.
D)H₂ + O₂ → H₂O.
E)P + 3 O → PO₃.

Answer 1

B

Question 2

In the ETS,________ accepts electrons from one molecule and transfers them to another.

A)a hydrogen ion
B)a coenzyme
C)the acetyl group
D)ADP
E)NAD

Answer 2

B

Question 3

In order for glycolysis to proceed,which of the following need not be present?

A)glucose
B)acetyl-CoA
C)ATP
D)NAD
E)ADP

Answer 3

B

Question 4

The function of the citric acid cycle is to

A)remove hydrogen atoms from organic molecules and transfer them to coenzymes.
B)transfer the acetyl group gained from glycolysis to molecules of pyruvate.
C)hydrolyze glucose in the presence of oxygen to obtain two pyruvate molecules.
D)produce carbon dioxide to balance the oxygen requirement for cellular respiration.
E)produce water.

Question 5

The sum of all of the biochemical processes going on within the human body at any given time is called

A)glycolysis.
B)oxidative phosphorylation.
C)catabolism.
D)anabolism.
E)metabolism.

Question 6

In glycolysis,each molecule of glucose that is catabolized gives a net yield of how many molecules of ATP?

A)2
B)4
C)30
D)36
E)38

Question 7

Cells synthesize new organic components for which of the following reasons?

A)structural maintenance
B)growth and repair
C)produce secretions
D)store nutrients
E)All of the answers are correct.

Question 8

The carbon dioxide of respiration is formed during

A)glycolysis.
B)the citric acid cycle.
C)electron transport.
D)the formation of pyruvic acid.
E)the formation of water.

Question 9

The citric acid cycle

A)begins with the formation of a molecule of citric acid.
B)directly produces most of the ATP from the catabolism of glucose.
C)consumes two moles of carbon dioxide.
D)contains enzymes called cytochromes.
E)forms acetyl-CoA from glucose-6-phosphate.

Question 10

Reactions within ________ provide most of the energy needed by a typical cell.

A)cytoplasm
B)the plasma membrane
C)the mitochondria
D)the endoplasmic reticulum
E)nucleus

Question 11

During glycolysis,

A)a molecule of glucose is converted into two molecules of pyruvic acid.
B)four molecules of ATP are produced.
C)two molecules of ATP are consumed.
D)hydrogen atoms are removed from organic molecules.
E)All of the answers are correct.

Question 12

What percent of energy released from catabolism is lost as heat?

A)20
B)30
C)40
D)50
E)60

Question 13

The major steps in oxidative phosphorylation include all of the following except

A)removal of hydrogen atoms from a substrate molecule by coenzymes.
B)ionization of hydrogen atoms.
C)decreasing the energy level of electrons passing through the electron transport chain.
D)the breaking of carbon-carbon covalent bonds.
E)the acceptance of electrons by oxygen atoms.

Question 14

The study of the flow of energy and its transformations is called

A)energetics.
B)glycolysis.
C)cellular respiration.
D)thermodynamics.
E)metabolism.

Question 15

The strategy of eating starchy foods for several days before an athletic event is known as

A)carbohydrate craving.
B)the Atkins diet.
C)carbohydrate loading.
D)glycolysis reaction.
E)overeating.

Question 16

Although other nutrients can feed into the citric acid cycle,________ yields energy the quickest.

A)glycogen
B)glucose
C)protein
D)fat
E)an amino acid

Question 17

The ________ of the mitochondrion contains large-diameter pores that are permeable to ions and small organic molecules such as pyruvic acid.

A)inner membrane
B)plasma membrane
C)outer membrane
D)matrix
E)cristae

Question 18

In the electron transport chain,

A)NADH and FADH₂ donate hydrogen atoms.
B)reduced molecules transfer energy to ATP formation.
C)oxidative phosphorylation leads to ATP formation.
D)generates a concentration gradient by pumping hydrogen ions.
E)All of the answers are correct.

Question 19

Cells perform catabolism to generate ATP,which can be used for

A)muscle contraction.
B)ion transport.
C)protein synthesis.
D)glycogen synthesis.
E)All of the answers are correct.

Question 20

Each cytochrome contains a(n)

A)lipoprotein.
B)metal ion.
C)ATP synthase.
D)inorganic salt.
E)All of the answers are correct.

Question 21

Figure 25-1 The Citric Acid Cycle
Use Figure 25-1 to answer the following questions:
What is the molecule labeled "5"?

A)fumaric acid
B)citrate 6-carbon
C)4-carbon molecule
D)malic acid
E)oxaloacetic acid

Question 22

How many net ATP molecules are produced by the complete metabolism (all pathways)of one glucose molecule?

A)2 ATP
B)63 ATP
C)500 ATP
D)36 ATP
E)32 ATP

Question 23

The end products of aerobic respiration are

A)carbon dioxide,water,and ATP.
B)pyruvic acid and carbon dioxide.
C)carbon dioxide and alcohol.
D)oxygen and water.
E)NADH and FADH2.

Question 24

Figure 25-1 The Citric Acid Cycle
Use Figure 25-1 to answer the following questions:
What is the molecule labeled "2"?

A)hydrogen atoms
B)citric acid
C)NADH
D)carbon dioxide
E)FADH₂

Question 25

The end products of glycolysis are

A)ATP,water,and carbon dioxide.
B)ATP,NADH,and pyruvic acid.
C)ADP and ATP.
D)pyruvic acid and citric acid.
E)NADH and FADH2.

Question 26

Figure 25-1 The Citric Acid Cycle
Use Figure 25-1 to answer the following questions:
What is the substance labeled "4"?

A)hydrogen atoms
B)citric acid
C)4 carbon molecule
D)NADH
E)FADH₂

Question 27

When NAD+ is ________ it becomes NADH.When NADH is ________ it becomes NAD+.

A)phosphorylated; deaminated
B)reduced; oxidized
C)made; recycled
D)phosphorylated; dephosphorylated
E)oxidized; reduced

Question 28

In the citric acid cycle,a 2 carbon molecule and a 4 carbon molecule combine to produce

A)fructose-1,6-bisphosphate.
B)carbon dioxide.
C)pyruvic acid.
D)NADH.
E)citric acid.

Question 29

What is the role of NADH in metabolism?

A)convert pyruvic acid into acetyl-coA
B)produce bicarbonate ions for a pH buffer
C)transport hydrogen atoms to coenzymes
D)produce carbon dioxide
E)phosphorylate ADP into ATP

Question 30

The citric acid cycle occurs in the

A)cytosol.
B)golgi apparatus.
C)mitochondrial intermembrane space.
D)mitochondrial matrix.
E)ribosome.

Question 31

In oxidative phosphorylation,energy for the synthesis of ATP is directly obtained from the

A)splitting of oxygen molecules.
B)breaking of the covalent bonds in glucose.
C)movement of hydrogen ions through channels in the inner mitochondrial membrane.
D)combination of two atoms of hydrogen and one atom of oxygen to form water.
E)oxidation of acetyl-CoA.

Question 32

The citric acid cycle is an aerobic process because

A)ADP is phosphorylated.
B)FADH2 is produced.
C)citric acid molecules have oxygen atoms.
D)oxygen is needed to remove carbon atoms as carbon dioxide.
E)NAH+ is converted into NADH.

Question 33

The essential fatty acids are

A)linoleic acid and linolenic acid.
B)leucine and lysine.
C)cholesterol and glycerol.
D)HDLs and LDLs.
E)glycerol and pyruvic acid.

Question 34

Most of the ATP from metabolism is produced in the

A)citric acid cycle.
B)electron transport system.
C)cytosol.
D)mitochondrial matrix.
E)glycolysis.

Question 35

Figure 25-1 The Citric Acid Cycle
Use Figure 25-1 to answer the following questions:
What is the molecule labeled "1"?

A)phosphoglyceric acid
B)citric acid
C)pyruvate
D)NADH
E)FADH₂

Question 36

The main purpose of the citric acid cycle is to

A)produce Acetyl CoA so that the citric acid cycle can continue.
B)produce proteins for energy storage.
C)phosphorylate glucose molecules.
D)supply hydrogen atoms to the Electron Transport System.
E)produce citric acid to make vitamin C in the mitochondria.

Question 37

Figure 25-1 The Citric Acid Cycle
Use Figure 25-1 to answer the following questions:
What is the molecule labeled "7"?

A)hydrogen atoms
B)citric acid
C)4 carbon molecule
D)NADH
E)FADH₂

Question 38

Hydrogen atoms from one FADH₂ from the citric acid cycle produce how much ATP in the electron transport system?

A)32 ATP
B)2 ATP
C)3 ATP
D)4 ATP
E)1 ATP

Question 39

Oxygen is an important molecule in which of the following?

A)citric acid cycle and ETS
B)glycolysis,citric acid cycle,and ETS
C)citric acid cycle only
D)glycolysis only
E)ETS only

Question 40

If 8 molecules of NADH from the citric acid cycle entered the ETS,how much ATP would be produced?

A)36 ATP
B)32 ATP
C)3 ATP
D)8 ATP
E)24 ATP

Question 41

A high uric acid level (above 7.4 mg/dl)can lead to the painful condition known as

A)gout.
B)rheumatoid arthritis.
C)anorexia nervosa.
D)lupus.
E)ketosis.

Question 42

The conversion of ammonia into a less toxic substance produces

A)ketone bodies.
B)urea.
C)nitrate.
D)acetyl-CoA.
E)water.

Question 43

In transamination,the amino group of an amino acid is

A)converted to ammonia.
B)converted to urea.
C)transferred to a keto acid.
D)absorbed by water.
E)transferred to acetyl-CoA.

Question 44

For adults,there are ________ essential amino acids.

A)2
B)6
C)8
D)10
E)20

Question 45

The lipoproteins that carry absorbed lipids from the intestinal tract to the bloodstream are

A)HDLs.
B)VLDLs.
C)LDLs.
D)chylomicrons.
E)coenzymes.

Question 46

Lipogenesis generally begins with

A)glucose.
B)amino acids.
C)fatty acids.
D)acetyl-CoA.
E)succinyl-CoA.

Question 47

Someone with a total cholesterol level above their optimal range should

A)modify their diet.
B)lose weight if overweight.
C)have annual checkups.
D)reduce the amount of saturated fat in the diet.
E)All of the answers are correct.

Question 48

During the absorptive state,

A)the liver forms glycogen.
B)adipocytes release fatty acids to the circulation.
C)skeletal muscle breaks down glycogen.
D)insulin levels are low.
E)skeletal muscle fibers release glucose.

Question 49

Urea is formed in the

A)liver.
B)stomach.
C)kidneys.
D)small intestine.
E)large intestine.

Question 50

Linoleic acid and linolenic acid are examples of

A)transport proteins.
B)lipoproteins.
C)essential fatty acids.
D)essential amino acids.
E)vitamins.

Question 51

Catabolism of protein is not a practical source of quick energy because of all of the following except that

A)proteins are more difficult to break apart than lipids or carbohydrates.
B)the energy yield from protein is less than the yield from lipids.
C)one of the by-products of protein catabolism is ammonia.
D)most individuals have little protein to spare before harming vital organs.
E)extensive catabolism of protein threatens homeostasis.

Question 52

________ carry excess cholesterol from peripheral tissues to the liver.

A)Very-low-density lipoproteins (VLDLs)
B)Low-density lipoproteins (LDLs)
C)Intermediate-density lipoproteins (IDLs)
D)High-density lipoproteins (HDLs)
E)Very-high-density lipoproteins (VHDLs)

Question 53

In the human body,cholesterol is important because it

A)helps waterproof the epidermis.
B)is a lipid component of all cell membranes.
C)is a key constituent of bile.
D)is the precursor of several steroid hormones and vitamin D₃.
E)All of the answers are correct.

Question 54

In order to determine the LDL level in a patient's blood,it is necessary to measure

A)total cholesterol level.
B)HDL level.
C)triglyceride level.
D)triglyceride and monoglyceride levels.
E)total cholesterol level,HDL level,and triglyceride level.

Question 55

Metabolism of amino acids in the citric acid cycle yields

A)more energy than lipid metabolism.
B)more energy than carbohydrate metabolism.
C)approximately the same energy as lipid metabolism.
D)approximately the same energy as carbohydrate metabolism.
E)more energy than lipid and carbohydrate metabolism combined.

Question 56

Removal of the amino group from amino acids in the first step of their catabolism requires a coenzyme derived from vitamin

A)A)
B)C)
C)B₁₂.
D)B₆.
E)B₉.

Question 57

During lipolysis,

A)triglycerides are converted into molecules of acetyl-CoA.
B)triglycerides are broken down into glycerol and fatty acids.
C)lipids are converted into glucose molecules.
D)lipids are formed from excess carbohydrates.
E)lipids are metabolized to yield ATP.

Question 58

All of the following are true of beta-oxidation except that

A)it occurs in the mitochondria.
B)fatty acids break down into two-carbon fragments.
C)lipids are converted into glycogen molecules.
D)it requires coenzyme A,NAD,and FAD.
E)it yields large amounts of ATP.

Question 59

________ are the largest lipoproteins,ranging in diameter up to 0.5 µm,produced by intestinal epithelial cells from the fats in food.

A)Very-low-density lipoproteins (VLDLs)
B)Low-density lipoproteins (LDLs)
C)Intermediate-density lipoproteins (IDLs)
D)High-density lipoproteins (HDLs)
E)Chylomicrons

Question 60

Lipids

A)deliver somewhat less energy than an equivalent mass of glucose.
B)are difficult to store since they are not water soluble.
C)yield quick bursts of energy.
D)provide energy for cells with modest energy demands.
E)are the primary nutrient metabolized in cells.

Question 61

All of the following complement the actions of glucocorticoids in the postabsorptive state except

A)insulin.
B)growth hormone.
C)glucagon.
D)epinephrine.

Question 62

During starvation,

A)carbohydrate utilization increases.
B)gluconeogenesis ceases.
C)there is a decline in circulating ketone bodies.
D)muscle proteins are used as an energy source.
E)carbohydrate reserves maintained by metabolizing inorganic compounds.

Question 63

When the body is relying on internal energy reserves to continue meeting its energy demands,it is in the ________ state.

A)postabsorptive
B)absorptive
C)starvation
D)deprivation
E)preabsorptive

Question 64

An ion that is a necessary component of high-energy compounds and nucleic acids and a structural component of bone is the ________ ion.

A)chloride
B)sulfate
C)phosphate
D)bicarbonate
E)iodide

Question 65

The presence of ketone bodies in the urine is known as

A)polyuria.
B)hematuria.
C)ketonuria.
D)uremia.
E)ketosis.

Question 66

The trace element needed as a cofactor for hemoglobin synthesis is

A)zinc.
B)copper.
C)cobalt.
D)iodine.
E)silicon.

Question 67

Compounds that cells can use to make glucose include all of the following,except

A)acetyl-CoA.
B)glycerol.
C)some amino acids.
D)lactate.
E)pyruvate.

Question 68

The major anion in body fluids is

A)chloride.
B)bicarbonate.
C)sulfate.
D)iodide.

Question 69

The element that is necessary for the proper function of the enzyme carbonic anhydrase is

A)iron.
B)cobalt.
C)zinc.
D)selenium.
E)iodine.

Question 70

During the postabsorptive state,________ stimulate(s)lipid catabolism.

A)glucocorticoids
B)androgens
C)insulin
D)glucagon
E)All of the answers are correct.

Question 71

On a tour of African countries,Mark contracts a bad case of traveler's diarrhea.Because he can't eat very much,his body starts to use energy sources other than carbohydrates.This would result in

A)increased levels of urea in the blood.
B)ketosis and a decreased blood pH.
C)increased gluconeogenesis in the liver.
D)lipid metabolism.
E)All of the answers are correct.

Question 72

A balanced diet should

A)include adequate substrates for the production of energy.
B)provide essential amino acids and fatty acids.
C)contain adequate amounts of vitamins and minerals.
D)contain adequate amounts of water.
E)All of the answers are correct.

Question 73

A cation that often acts as a cofactor for enzymes is

A)sodium.
B)potassium.
C)calcium.
D)magnesium.
E)zinc.

Question 74

All of the following occur during the postabsorptive state except that

A)glycogenolysis occurs in the liver.
B)levels of blood glucose are elevated.
C)ketone bodies may be formed.
D)fat mobilization occurs.
E)gluconeogenesis occurs in the liver.

Question 75

A cation that is essential for muscle contraction,nerve function,and blood clotting is

A)sodium.
B)potassium.
C)calcium.
D)magnesium.
E)selenium.

Question 76

The major cation in cytoplasm is

A)sodium.
B)potassium.
C)calcium.
D)magnesium.
E)iron.

Question 77

The major cation in extracellular fluid is

A)sodium.
B)potassium.
C)calcium.
D)magnesium.
E)iron.

Question 78

Nitrogen compounds of the body include all of the following except

A)amino acids.
B)oxaloacetate.
C)creatine.
D)porphyrin.
E)purines.

Question 79

An element that is a component of hemoglobin,myoglobin,and cytochromes is

A)calcium.
B)magnesium.
C)iron.
D)zinc.
E)cobalt.

Question 80

Wally decides to go on a hunger strike to further one of his favorite causes.After many days with nothing but water,you would not expect to observe

A)elevated levels of glucocorticoids.
B)ketone bodies in his urine.
C)decreased blood pH.
D)increased insulin secretion.
E)All of the answers are correct.