Deck 17: Metabolism and Energetics

Question 1

Regarding the citric acid cycle,which molecule participates in a complex reaction involving NAD and coenzyme A within the mitochondrion?

A) pyruvate
B) citric acid
C) ATP
D) oxygen
E) FADH₂

Answer 1

A

Question 2

Which of the following may not be used for gluconeogenesis because their breakdown produces acetyl CoA?

A) fatty acids
B) complex carbohydrates
C) glycerol
D) nucleic acids
E) glycogen

Answer 2

A

Question 3

Performance in endurance sports improves if muscles have large stores of

A) nucleic acids.
B) protein reserves.
C) lipid reserves.
D) amino acids.
E) carbohydrate reserves.

Answer 3

E

Question 4

About 40% of the energy released through catabolism is used to convert ADP to ATP.What happens to the remaining 60% of energy?

A) It is destroyed during the catabolic activities.
B) It is used to convert RNA to DNA.
C) It is immediately used in anabolic processes.
D) It escapes as heat to warm the tissues.
E) It transforms into mechanical energy.

Question 5

The sum of all of the chemical reactions occurring within the human body is called

A) glycolysis.
B) oxidation.
C) catabolism.
D) anabolism.
E) metabolism.

Question 6

For each molecule of glucose processed,a typical cell gains ________ molecules of ATP.

A) 2-3
B) 6-8
C) 15-16
D) 30-32
E) 60-64

Question 7

Figure 17-1 The Citric Acid Cycle
Use Figure 17-1 to identify the element marked with a letter. (Example: CO₂, H₂O)
The ion(s)or molecule(s)labeled A is (are)

A) CO₂.
B) H₂O.
C) O₂.
D) H⁺.
E) 2H.

Question 8

Which of the following is the first intermediate formed in the citric acid cycle?

A) coenzyme A
B) pyruvate
C) FADH₂
D) citric acid
E) oxygen

Question 9

Carbohydrate metabolism involves the reactants,glucose plus oxygen,and the resultant products

A) pyruvate and nitrogen.
B) carbon dioxide and water.
C) water and sucrose.
D) nitrogen and hydrogen.
E) water and pyruvate.

Question 10

In the liver and skeletal muscles,glucose molecules are stored as

A) triglycerides.
B) fatty acids.
C) pyruvate.
D) sucrose.
E) glycogen.

Question 11

Cyanide poisoning quickly leads to death because it blocks the final cytochrome molecule in the electron transport system.Why is this blockage lethal?

A) All hydrogen ion pumps deactivate.
B) NADH molecules cannot give off their electrons.
C) FADH₂ molecules cannot give off their electrons.
D) Electrons cannot transfer to oxygen.
E) Coenzyme Q disassociates and becomes nonfunctional.

Question 12

Figure 17-1 The Citric Acid Cycle
Use Figure 17-1 to identify the element marked with a letter. (Example: CO₂, H₂O)
The ion(s)or molecule(s)labeled C is (are)

A) CO₂.
B) H₂O.
C) O₂.
D) H⁺.
E) 2H.

Question 13

When actively contracting,skeletal muscles catabolize glucose,but at rest they rely on which of the following?

A) proteins
B) glycogen
C) nucleic acids
D) fatty acids
E) amino acids

Question 14

In the electron transport system (ETS),which of the following are pumped into the intermembrane space,providing the concentration gradient essential for the generation of ATP?

A) oxygen molecules
B) water molecules
C) ATP molecules
D) hydrogen ions
E) cytochromes

Question 15

The synthesis of new organic molecules,involving the formation of new chemical bonds,is called

A) glycolysis.
B) catabolism.
C) anabolism.
D) differentiation.
E) lipolysis.

Question 16

Place the following steps of the electron transport system (ETS)and ATP formation in the correct order. 1.Movement of hydrogen ions provides energy to ATP synthesis.
2)Electrons from FADH₂ pass to coenzyme Q.
3)Electrons are transported to respiratory complex III.
4)ADP combines with P to form ATP.
5)Electrons from NADH pass to coenzyme Q.
6)Electrons combine with oxygen and hydrogen ions to form water molecules.

A) 6, 3, 5, 2, 4, 1
B) 5, 2, 3, 6, 1, 4
C) 1, 2, 6, 4, 3, 5
D) 4, 6, 1, 3, 5, 2
E) 2, 3, 6, 5, 4, 1

Question 17

Gluconeogenesis is the synthesis of glucose from precursor molecules such as

A) sucrose.
B) glycerol.
C) fructose.
D) glycogen.
E) galactose.

Question 18

Most cells generate ATP and other high-energy compounds by breaking down carbohydrates,especially

A) ribose.
B) galactose.
C) sucrose.
D) fructose.
E) glucose.

Question 19

During glycolysis in the cytoplasm,the cell gains how many molecules of ATP for each glucose molecule broken down to pyruvate?

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

Question 20

Figure 17-1 The Citric Acid Cycle
Use Figure 17-1 to identify the element marked with a letter. (Example: CO₂, H₂O)
The ion(s)or molecule(s)labeled B is (are)

A) CO₂.
B) H₂O.
C) O₂.
D) H⁺.
E) 2H.

Question 21

A cell produces how many ATP molecules from the breakdown of one 18-carbon fatty acid molecule?

A) 4
B) 16
C) 120
D) 32
E) 60

Question 22

Figure 17-1 The Citric Acid Cycle
Use Figure 17-1 to identify the element marked with a letter. (Example: CO₂, H₂O)
The ion(s)or molecule(s)labeled G is (are)

A) CO₂.
B) H₂O.
C) O₂.
D) H⁺.
E) 2H.

Question 23

Due to an enzyme defect,individuals with phenylketonuria cannot convert the amino acid phenylalanine to

A) urea.
B) tyrosine.
C) ketones.
D) serotonin.
E) ATP.

Question 24

Which of the following delivers cholesterol to peripheral tissues?

A) triglycerides
B) low-density lipoproteins
C) high-density lipoproteins
D) free fatty acids
E) glycerol groups

Question 25

Which of the following is the maximum "healthy" cholesterol level in a typical 19-year-old male?

A) 230 mg/dL
B) 185 mg/dL
C) 200 mg/dL
D) 350 mg/dL
E) 250 mg/dL

Question 26

Protein catabolism is an impractical source of quick energy because

A) the major byproduct is hydrogen, which cells cannot use for energy.
B) proteins are unimportant to cellular homeostasis.
C) the body cannot synthesize any of the amino acids, which it needs.
D) proteins are catabolized much too easily, resulting in homeostatic imbalance.
E) proteins are more difficult to catabolize than are complex carbohydrates or lipids.

Question 27

Glycerol enters the citric acid cycle after enzymes in the cytosol convert it to

A) glucose.
B) pyruvate.
C) glycogen.
D) LDL/HDL.
E) cholesterol.

Question 28

Which is accurate regarding ketoacidosis?

A) Blood pH may drop below 7.05.
B) Blood pH may rise to 9.05.
C) Blood pH is not affected.
D) Increased alkalinity of body tissues occurs.
E) Conditions do not ever become so severe that coma results.

Question 29

Molecules that carry excess cholesterol from peripheral tissues to the liver for storage or secretion in the bile are called

A) low-density lipoproteins (LDLs).
B) high-density lipoproteins (HDLs).
C) fatty acids.
D) steroids.
E) chylomicrons.

Question 30

Figure 17-1 The Citric Acid Cycle
Use Figure 17-1 to identify the element marked with a letter. (Example: CO₂, H₂O)
The ion(s)or molecule(s)labeled D is (are)

A) CO₂.
B) H₂O.
C) O₂.
D) H⁺.
E) 2H.

Question 31

Figure 17-1 The Citric Acid Cycle
Use Figure 17-1 to identify the element marked with a letter. (Example: CO₂, H₂O)
The ion(s)or molecule(s)labeled E is (are)

A) CO₂.
B) H₂O.
C) O₂.
D) H⁺.
E) 2H.

Question 32

Lipogenesis of steroids and almost all fatty acids begins with

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

Question 33

Lipids that can diffuse easily across plasma membranes are called

A) triglycerides.
B) steroids.
C) albumins.
D) high-density lipoproteins.
E) free fatty acids.

Question 34

In transamination,the amino group of an amino acid is transferred to

A) ammonia.
B) urea.
C) another carbon chain.
D) a molecule in the glycolytic pathway.
E) acetyl CoA.

Question 35

Lipid catabolism yields 1.3 times as much ATP compared to aerobic glucose metabolism.So why is lipid catabolism not the prime source of ATP in the human body?

A) Most people do not have enough lipid reserves.
B) Water-soluble enzymes cannot easily get to the lipid droplets.
C) Lipid catabolism occurs in the cytosol where oxygen availability is limited.
D) Lipid catabolism occurs primarily during times of starvation.
E) Lipid catabolism produces large amounts of nitrogenous wastes, which are taxing on the liver.

Question 36

Which of the following is never catabolized for energy,even in cells dying of starvation?

A) DNA
B) proteins
C) rRNA
D) tRNA
E) mRNA

Question 37

Figure 17-1 The Citric Acid Cycle
Use Figure 17-1 to identify the element marked with a letter. (Example: CO₂, H₂O)
The ion(s)or molecule(s)labeled F is (are)

A) CO₂.
B) H₂O.
C) O₂.
D) H⁺.
E) 2H.

Question 38

Beta-oxidation

A) occurs in the mitochondria and is a series of reactions that break down fatty acids.
B) breaks down proteins into two-carbon fragments that can be metabolized by the citric acid cycle.
C) yields large amounts of ATP, while requiring coenzyme A, NAD, and FAD.
D) occurs during glycolysis and generates NAD and FAD molecules.
E) is the final step of the citric acid cycle where hydrogen ions enter the electrons transport system.

Question 39

Synthesis of ________ occurs only in cells preparing for mitosis or meiosis.

A) ribosomal RNA (rRNA)
B) cholesterol
C) messenger RNA (mRNA)
D) DNA
E) transfer RNA (tRNA)

Question 40

The process of deamination produces

A) keto acids.
B) high levels of proteins.
C) an ammonium ion.
D) acetyl CoA.
E) B vitamins.

Question 41

The vitamin that functions as part of coenzyme A is

A) pantothenic acid (B₅).
B) nicotinic acid (B₃).
C) folic acid (B₉).
D) cobalamin (B₁₂).
E) riboflavin (B₂).

Question 42

A mineral that is a necessary cofactor for hemoglobin synthesis is

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

Question 43

Which of the following is a major anion in body fluids,primarily excreted through urine and sweat?

A) sodium
B) chloride
C) potassium
D) calcium
E) zinc

Question 44

Which of the following is a complete protein source?

A) corn
B) spinach
C) rice
D) eggs
E) oranges

Question 45

This mineral is a cofactor of the carbonic anhydrase enzyme system.

A) chloride
B) calcium
C) copper
D) zinc
E) magnesium

Question 46

The vitamin that is a constituent of coenzyme FAD is

A) thiamine (B₁).
B) riboflavin (B₂).
C) niacin (nicotinic acid).
D) folate (B₉).
E) cobalamin (B₁₂).

Question 47

The vitamin that is required for the synthesis of visual pigments is

A) vitamin A.
B) vitamin B.
C) vitamin C.
D) vitamin D.
E) vitamin E.

Question 48

Which fat-soluble vitamin is synthesized in skin that is exposed to sunlight?

A) vitamin K
B) vitamin E
C) vitamin B₆ (pyridoxine)
D) vitamin D
E) vitamin C

Question 49

Hypovitaminosis of vitamin B₁₂ can cause pernicious anemia,however,hypervitaminosis can cause

A) polycythemia.
B) possible lethal CNS alterations.
C) hypotension.
D) kidney stones.
E) itching and tingling sensations.

Question 50

Which bulk mineral is a major cation in body fluids and is essential for normal membrane function?

A) calcium
B) iron
C) sodium
D) chloride
E) phosphorus

Question 51

Which of the following is a fat-soluble vitamin?

A) vitamin K
B) vitamin C
C) vitamin B₆
D) niacin
E) riboflavin

Question 52

Which of the following is a trace mineral?

A) chloride
B) sodium
C) calcium
D) iron
E) magnesium

Question 53

An ion that is a necessary component of high-energy compounds,nucleic acids,and bone matrix is

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

Question 54

A bulk mineral that is essential for normal muscle and neuron function as well as for bone structure is

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

Question 55

The natural dietary sources for vitamin B₁₂ (cobalamin)are

A) fruits only.
B) meats and milk.
C) vegetables only.
D) breads and potatoes.
E) leafy vegetables.

Question 56

Nucleotides from RNA

A) are deaminated to form ammonia.
B) can provide sugars for glycolysis, in order to form ATP.
C) can be used to synthesize proteins.
D) cannot be used as a source of energy in place of ATP.
E) cannot be recycled.

Question 57

________ is a trace mineral that is a component of hemoglobin,myoglobin,and cytochromes.

A) Magnesium
B) Calcium
C) Zinc
D) Copper
E) Iron

Question 58

Which of the following comprise the best source of vitamin C?

A) milk and meat
B) bread and potatoes
C) vegetables
D) citrus fruits
E) breads and cheeses

Question 59

The vitamin that is essential for liver synthesis of prothrombin and other clotting factors is

A) vitamin A.
B) vitamin B.
C) vitamin E.
D) vitamin C.
E) vitamin K.

Question 60

________ are inorganic ions released through electrolytes,such as sodium chloride.

A) Minerals
B) Enzymes
C) Water-soluble vitamins
D) Essential proteins
E) Fat-soluble vitamins

Question 61

Which of the following activities expends the most calories per hour?

A) speed walking
B) jogging
C) slow walking
D) competitive swimming
E) climbing stairs

Question 62

The heat-loss and heat-gain centers of the body are found in which of the following?

A) hippocampus
B) medulla oblongata
C) hypothalamus
D) pons
E) cerebellum

Question 63

An average individual has a basal metabolic rate (BMR)of about

A) 400 cal/hr.
B) 3680 cal/hr.
C) 70 cal/hr.
D) 7000 cal/day.
E) 145 cal/hr.

Question 64

The daily average water requirement for humans is

A) 250 ml.
B) 2500 ml.
C) 500 ml.
D) 1500 ml.
E) 1000 ml.

Question 65

An example of nonshivering thermogenesis occurs when epinephrine from the adrenal glands immediately increases the breakdown of glycogen in the

A) heart and lungs.
B) liver and skeletal muscles.
C) kidneys and pancreas.
D) skin and accessory glands.
E) hypothalamus and pons.

Question 66

The direct transfer of energy through physical contact is called

A) evaporation.
B) condensation.
C) convection.
D) radiation.
E) conduction.

Question 67

Which of the following minerals is a cofactor for some enzymes and is a mineral whose primary route of excretion is through feces and trace amounts in urine?

A) chloride
B) copper
C) iron
D) manganese
E) calcium

Question 68

Beriberi is a degenerative disease caused by a deficiency of ________,having the effects of muscle weakness and CNS and cardiovascular problems including heart disease.

A) vitamin B₁ (thiamine)
B) vitamin B₁₂ (cobalamin)
C) vitamin C (ascorbic acid)
D) niacin (nicotinic acid)
E) vitamin B₂ (riboflavin)

Question 69

Which water-soluble vitamin must first be bound to the intrinsic factor secreted by the gastric mucosa before it can be absorbed by the intestinal epithelium?

A) vitamin B₂ (riboflavin)
B) vitamin C (ascorbic acid)
C) vitamin B₁₂ (cobalamin)
D) vitamin B₅ (pantothenic acid)
E) vitamin B₆ (pyridoxine)

Question 70

A patient complains of blurred vision and fatigue.A diagnostic exam reveals that she has been taking megadoses of ________ supplements.

A) vitamin K
B) vitamin E
C) vitamin C
D) vitamin A
E) vitamin D

Question 71

The vitamin that is a coenzyme in amino acid and lipid metabolism is

A) vitamin B₆ (pyridoxine).
B) vitamin B₅ (pantothenic acid).
C) vitamin B₂ (riboflavin).
D) vitamin B₉ (folic acid).
E) niacin (nicotinic acid).

Question 72

During times of increased body temperature,which of the following physiological responses is most likely to occur?

A) Vasomotor center is stimulated.
B) Sweat glands decrease their secretions.
C) Respiratory centers are inhibited.
D) Nonshivering thermogenesis is inhibited.
E) Shivering thermogenesis is stimulated.

Question 73

Charlie has a blood test that shows a normal level of LDLs but an elevated level of HDLs in his blood.Since his family has a history of cardiovascular disease,he wonders if he should modify his lifestyle.What should one advise him to do or not to do?

Question 74

Which of the following processes of heat transfer is the result of heat loss to the air that overlies the surface of an object?

A) radiation
B) conduction
C) evaporation
D) condensation
E) convection

Question 75

Mucosal deterioration is a sign of hypovitaminosis for vitamins C,B₂,and

A) B₃.
B) A.
C) D.
D) K.
E) C.

Question 76

A Calorie unit used in food is equal to the amount of energy necessary to raise the temperature of 1 kilogram of water ________ degree(s)Celsius.

A) 1
B) 2
C) 10
D) 100
E) 1,000

Question 77

The vitamin that is a coenzyme in amino acid and nucleic acid metabolism is

A) vitamin B₅ (pantothenic acid).
B) vitamin B₆ (pyridoxine).
C) vitamin B₉ (folic acid).
D) vitamin C (ascorbic acid).
E) vitamin K.