Deck 7: Metabolism: Transformations and Interactions

Question 1

What is the approximate percent efficiency of conversion of food energy to ATP energy in the body?

A)20
B)50
C)80
D)99

Answer 1

B

Question 2

Which of the following can not be formed from pyruvate in human beings?

A)Glucose
B)Fructose
C)Lactic acid
D)Linoleic acid

Answer 2

D

Question 3

A feature of catabolic reactions is that they

A)involve release of energy.
B)occur only in mitochondria.
C)involve consumption of energy.
D)occur only during loss of body weight.

Answer 3

A

Question 4

Which of the following is a feature of aerobic metabolism?

A)Little or no oxygen is consumed
B)Lactic acid is a major byproduct
C)Energy is produced more slowly than in anaerobic metabolism
D)Pyruvate is converted to glucose by reverse glycolysis to yield a net of 2 ATPs

Question 5

Glycolysis is the conversion of

A)glycogen to fat.
B)glycogen to protein.
C)glucose to pyruvate.
D)glucose to glycogen.

Question 6

In photosynthesis, the plant uses energy from the sun, plus water and carbon dioxide, to synthesize

A)carbohydrates only.
B)fats and carbohydrates only.
C)protein and carbohydrates only.
D)fats, proteins, and carbohydrates.

Question 7

The series of reactions involving the conversion of glucose to pyruvate is known as

A)pyrolysis.
B)glycolysis.
C)beta-oxidation.
D)coupled reaction.

Question 8

The hydrolysis of ATP that often occurs simultaneously with the synthesis of many compounds is an example of

A)coupled reactions.
B)tandem cleavages.
C)metabolic couplings.
D)high energy processes.

Question 9

All of the following are among the functions of the liver except

A)synthesis of urea.
B)synthesis of glycogen.
C)production of red blood cells.
D)conversion of fructose to glucose.

Question 10

The basic units derived from food include all of the following except

A)glycerol.
B)starches.
C)fatty acids.
D)amino acids.

Question 11

Which of the following defines a coenzyme?

A)A unit consisting of an enzyme bound to reactants plus ATP
B)An organic molecule required for the functioning of an enzyme
C)The small, active part of an enzyme that binds to the organic reactants
D)An inactive enzyme that becomes functional upon contact with specific cofactors

Question 12

What is the major energy carrier molecule in most cells?

A)ATP
B)Glucose
C)Pyruvate
D)A kcalorie

Question 13

Which of the following metabolic reactions occurs when a cell uses energy?

A)ATP gains a phosphate group and becomes ADP
B)ADP gains a phosphate group and becomes ATP
C)ATP releases a phosphate group and becomes ADP
D)ADP releases a phosphate group and becomes ATP

Question 14

An aerobic reaction is one that requires

A)alcohol.
B)oxygen.
C)nitrogen.
D)ammonia.

Question 15

Which of the following describes the sum of all chemical reactions that go on in living cells?

A)Digestion
B)Metabolism
C)Absorption
D)Catabolism

Question 16

Approximately what percentage of the body's energy expenditure is furnished by amino acids?

A)1 to 5
B)10 to 15
C)25 to 35
D)50 to 65

Question 17

What term is specific to reactions in which simple compounds are combined into more complex molecules?

A)Anabolic
B)Catabolic
C)Ergogenic
D)Gluconeogenic

Question 18

In the adult body, food energy not stored as fat or glycogen is lost as

A)heat.
B)photons.
C)carbon dioxide.
D)electromagnetic radiation.

Question 19

A typical cell contains "powerhouses," which is another name for the

A)DNA.
B)ribosomes.
C)mitochondria.
D)electron transport chains.

Question 20

Which of the following can not be formed from acetyl CoA molecules?

A)Glucose
B)Cholesterol
C)Stearic acid
D)Carbon dioxide

Question 21

When a person is performing intense physical exercise and begins to feel fatigue and a burning pain in the muscles, the response of the muscles is to synthesize more

A)lactate.
B)glucose.
C)citric acid.
D)fatty acids.

Question 22

Approximately what percentage of the weight of triglycerides cannot be converted to glucose?

A)70
B)80
C)90
D)95

Question 23

Fatty acid oxidation results in the direct production of

A)ketones.
B)fructose.
C)pyruvate.
D)acetyl CoA.

Question 24

What is the first product of fatty acid catabolism?

A)Glycerol
B)Pyruvate
C)Acetyl CoA
D)Triglycerides

Question 25

Which of the following cannot be used to make body proteins?

A)Glucose
B)Glycerol
C)Fatty acids
D)Amino acids

Question 26

Which of the following is a possible fate of acetyl CoA?

A)Degradation to urea
B)Synthesis to glycerol
C)Synthesis to fatty acids
D)Degradation to ammonia

Question 27

Which of the following is not a possible fate of metabolized glucose?

A)Urea
B)Acetyl CoA
C)Amino acids
D)Muscle glycogen

Question 28

Which of the following nutrients can be made from compounds composed of 2-carbon skeletons?

A)Glucose
B)Fructose
C)Glycogen
D)Fatty acids

Question 29

Production of excessive amounts of acetyl CoA molecules leads to the synthesis of

A)fatty acids only.
B)fatty acids and glucose only.
C)fatty acids and fructose only.
D)fatty acids, glucose, and amino acids.

Question 30

Your roommate Demetrius is participating in a weightlifting course and complains of a burning pain during workouts.You explain to Demetrius that the rapid breakdown of glucose in his muscles produces large amounts of pyruvate, which leads to a fall in pH within the muscle and that the muscle responds by converting excess pyruvate to

A)lactate.
B)glycerol.
C)acetyl CoA.
D)amino acids.

Question 31

An immediate consequence of a cellular deficiency of oxaloacetate is a slowing of

A)glycolysis.
B)the TCA cycle.
C)lactate synthesis.
D)ketone formation.

Question 32

All of the following may serve as precursors for oxaloacetate synthesis except

A)fat.
B)starch.
C)glucose.
D)protein.

Question 33

What percentage (by weight) of a triglyceride molecule can be converted to glucose?

A)0
B)5
C)50
D)100

Question 34

The Cori cycle involves the interconversion of

A)lactate and glucose.
B)glucose and amino acids.
C)pyruvate and citric acids.
D)fatty acids and acetyl CoA.

Question 35

How many acetyl CoA molecules may be obtained from oxidation of an 18-carbon fatty acid?

A)3
B)6
C)9
D)18

Question 36

What is the immediate fate of excess dietary protein in the body?

A)Stored
B)Reduced
C)Oxidized
D)Deaminated

Question 37

Which of the following compounds cannot be formed from fatty acids?

A)Ketones
B)Glucose
C)Acetyl CoA
D)Carbon dioxide

Question 38

Which of the following dietary components cannot be used to synthesize and store glycogen?

A)Lactose
B)Animal fats
C)Wheat starch
D)Plant protein

Question 39

In a triglyceride that contains 54 carbon atoms, how many can become part of glucose?

A)3
B)9
C)54
D)108

Question 40

When energy-yielding nutrients are consumed in excess, which one(s) can lead to storage of fat?

A)Fat only
B)Carbohydrate only
C)Fat and carbohydrate only
D)Fat, carbohydrate, and protein

Question 41

All of the following are features of the metabolism of surplus dietary carbohydrate in human beings except

A)excess glucose suppresses fat oxidation.
B)excess glucose is oxidized only very slowly.
C)excess glucose is first used to fill glycogen reserves.
D)conversion of excess glucose to fat occurs only to a very limited extent.

Question 42

How does excess carbohydrate intake contribute to obesity?

A)It is efficiently converted to storage fat
B)It spares oxidation of body fat and dietary fat
C)It stimulates glucagon release resulting in inhibition of fatty acid oxidation
D)It stimulates pancreatic lipase secretion, which results in higher dietary fat absorption

Question 43

The number of ATP molecules that can be produced from a molecule of protein, fat, or carbohydrate is generally related to the number of atoms of

A)carbon.
B)oxygen.
C)nitrogen.
D)hydrogen.

Question 44

At what point is oxygen used in the electron transport chain?

A)At the end
B)At every step
C)At the beginning
D)When ATP is synthesized

Question 45

What are the products from the complete oxidation of fatty acids?

A)Urea and acetone
B)Fatty acids and glycerol
C)Carbon, hydrogen, and oxygen
D)Water, carbon dioxide, and energy

Question 46

Which of the following accounts for the higher energy density of a fatty acid compared with the other energy-yielding nutrients?

A)Fatty acids have a lower percentage of hydrogen-carbon bonds
B)Fatty acids have a greater percentage of hydrogen-carbon bonds
C)Other energy-yielding nutrients have a lower percentage of oxygen-carbon bonds
D)Other energy-yielding nutrients undergo fewer metabolic reactions, thereby lowering the energy yield

Question 47

Approximately how many molecules of ATP are generated from the complete oxidation of one molecule of glucose?

A)4
B)9
C)32
D)130

Question 48

In addition to energy, what are the principal end products of cellular oxidation of carbohydrates?

A)Water and carbon dioxide
B)Carbon, hydrogen, and urea
C)Indigestible fiber and nitrogen
D)Monosaccharides and amino acids

Question 49

If the carbohydrate content of the diet is insufficient to meet the body's needs for glucose, which of the following can be converted to glucose?

A)Fatty acids
B)Acetyl CoA
C)Amino acids
D)Carbon dioxide

Question 50

Approximately how many ATP molecules are synthesized from the complete oxidation of a molecule of palmitic acid?

A)9
B)27
C)98
D)129
Section 7.3 Energy Balance

Question 51

Which of the following is the body's first response to the absorption of abundant amounts of carbohydrate?

A)Catabolism of body fat
B)Catabolism of glycogen
C)Synthesis and storage of glycogen
D)Synthesis and storage of triglycerides

Question 52

When protein consumption is in excess of body needs and energy needs are met, the excess amino acids are metabolized and the energy in the molecules is

A)stored as fat only.
B)excreted in the feces.
C)stored as amino acids only.
D)stored as glycogen and fat.

Question 53

Which of the following is a characteristic of the metabolism of specific macronutrients?

A)The rate of fat oxidation does not change when fat is eaten in excess
B)The rate of protein oxidation does not change when protein is eaten in excess
C)The rate of glucose oxidation does not change when carbohydrate is eaten in excess
D)The conversion of dietary glucose to fat represents the major pathway of carbohydrate utilization

Question 54

Jake is getting ready for spring training and is sitting down to a dinner of half a chicken, a rib-eye steak, black beans, and 5 slices of bacon.He has been eating typical dinners like this for about a month and has since gained 7 pounds, while exercising only briefly.When Jake asks why he doesn't see an increase in his biceps or abs, the proper response should be

A)dietary protein alone does not contribute to muscle accretion.
B)it takes at least 6 months to document changes in muscle accretion.
C)the weight he has gained can be attributed to a substantial increase in his protein stores.
D)because muscle accretion only responds to very lean meat choices, he should eliminate the fatty bacon and steak from his diet to promote muscle gain.

Question 55

If a person consumes 100 kcalories in excess of energy needs from table sugar, approximately how many of the kcalories are stored in the body?

A)25
B)50
C)75
D)100

Question 56

Which of the following can be synthesized from all three energy-yielding nutrients?

A)Lactate
B)Glycogen
C)Acetyl CoA
D)Oxaloacetate

Question 57

If a person consumes 100 kcalories in excess of energy needs from olive oil, approximately what percentage of the kcalories are stored in the body?

A)25
B)45
C)65
D)95

Question 58

Which of the following is the most likely explanation for the body's higher metabolic efficiency of converting a molecule of corn oil into stored fat compared with a molecule of sucrose?

A)The enzymes specific for metabolizing absorbed fat have been found to have higher activities than those metabolizing sucrose
B)The absorbed corn oil is transported to fat cells at a faster rate than the absorbed sucrose, thereby favoring the uptake of corn oil fat
C)There are fewer metabolic reactions for disassembling the corn oil and re-assembling the parts into a triglyceride for uptake by the fat cells
D)Because the energy content of corn oil is higher than sucrose, conversion of these nutrients into stored fat requires a smaller percentage of the energy from the corn oil

Question 59

Which of the following products is not generated via the TCA cycle or electron transport chain?

A)Water
B)Energy
C)Ammonia
D)Carbon dioxide

Question 60

Products from the electron transport chain pathway include all of the following except

A)CO₂.
B)urea.
C)water.
D)energy.

Question 61

After the first day or so of fasting, which of the following is most depleted in the body?

A)Glycogen
B)Fatty acids
C)Amino acids
D)Triglycerides

Question 62

Elizabeth has been fasting for 4 days in observance of her religious beliefs.You note that her breath smells "fruity." This is most likely due to

A)her intake of religious wafers.
B)her intake of dilute fruit juices.
C)her body's shift to a state of ketosis.
D)her body's switch to a lipogenic state.

Question 63

During the first few days of a fast, what energy source provides about 90% of the glucose needed to fuel the body?

A)Protein
B)Ketones
C)Glycogen
D)Triglycerides

Question 64

How soon would death occur from starvation if the body was unable to shift to a state of ketosis?

A)Within 3 weeks
B)Less than 2 weeks
C)Between 5 and 6 weeks
D)Between 2 and 3 months

Question 65

Of the total amount of carbohydrate energy consumed by the body, approximately what percentage is used by the brain and nerve cells?

A)10
B)30
C)50
D)90

Question 66

A feature of ketosis is that it

A)occurs from lack of protein in the diet.
B)occurs when fats are partially oxidized.
C)results from excess acetoacetate in the diet.
D)results from excess carbohydrate in the diet.

Question 67

A person said to have acetone breath most likely has the condition known as

A)ketonemia.
B)feasting syndrome.
C)acetyl CoA toxicity.
D)carbohydrate overload.

Question 68

Lillie has been losing weight by following a very-low-carbohydrate diet for 2 months.Her primary care physician just diagnosed ketosis through a urine sample.Which of the following symptoms would be another way the physician might have suspected ketosis in Lillie?

A)Thinning hair
B)Irritable temper
C)Fishy body odor
D)Fruity odor on breath

Question 69

A person with fruity odor on the breath demonstrates evidence of metabolic

A)ketosis.
B)alkalosis.
C)transamination.
D)anaerobic breakdown.

Question 70

Which of the following is a characteristic of ketosis?

A)It may lead to a lowering of blood pH
B)It leads to increased appetite in most individuals
C)It may be alleviated quickly by ingestion of some dietary fat
D)It is a necessary physiological adjustment for maximum weight loss

Question 71

If a normal person expends 1200 kcalories while at rest, approximately how many are used by the brain?

A)40
B)100
C)200
D)300

Question 72

Which of the following dietary nutrients would most rapidly reverse a state of ketosis in a starving person?

A)Fat
B)Protein
C)Amino acids
D)Carbohydrate

Question 73

Which of the following is used to supply some of the fuel needed by the brain only after the body has been fasting for a while?

A)Ketones
B)Glycerol
C)Fatty acids
D)Amino acids

Question 74

Which of the following is classified as a ketone body?

A)Sorbitol
B)Pyruvate
C)Acetyl CoA
D)Acetoacetate

Question 75

All of the following are general features of starvation in people except

A)a decrease in metabolic rate.
B)a decrease in mental alertness.
C)a decrease in immune function.
D)a decrease in body temperature.

Question 76

Ketonemia is defined as an elevation of

A)ketones in the blood.
B)ketones in the urine.
C)alpha-ketoglutarate in the blood.
D)alpha-ketoglutarate in the urine.

Question 77

Adverse side effects of typical low-carbohydrate diets include all of the following except

A)fatigue.
B)nausea.
C)constipation.
D)high blood pressure.

Question 78

The effects on metabolism from starvation are similar to those from

A)fasting.
B)feasting.
C)lipogenesis.
D)Cori cycling.

Question 79

How are ketones formed?

A)Condensation of lactic acid molecules
B)Condensation of acetyl CoA molecules
C)Hydrolysis of excess glycerol fragments
D)Hydrolysis of excess pyruvate fragments

Question 80

Which of the following is a feature of the metabolism of surplus dietary fat?

A)Excess fat is almost all stored
B)Excess fat promotes increased fat oxidation
C)Excess fat spares breakdown of body proteins
D)Conversion of excess fat to storage fat is inefficient