Deck 7: Metabolism: Transformations and Interactions

Question 1

In the adult body, most of the food energy NOT stored as fat or glycogen is lost as which of the following forms of energy?

A) heat
B) photons
C) macronutrients in stool
D) electromagnetic radiation

Answer 1

A

Question 2

In photosynthesis, the plant uses energy from the sun, plus water and carbon dioxide, to synthesize which of the following molecules?

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

Answer 2

A

Question 3

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

A) digestion
B) metabolism
C) absorption
D) catabolism

Answer 3

B

Question 4

Which of the following conversions is termed glycolysis?

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

Question 5

Which of the following best characterizes catabolic reactions?

A) involve release of energy
B) occur only in mitochondria
C) involve consumption of energy
D) occur only when dietary energy is inadequate

Question 6

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 7

The basic units derived from food that enter the TCA cycle directly or through pyruvate and acetyl CoA include all of the members of which of the following groups?

A) glycerol, starches, glucose
B) starches, peptides, fatty acids
C) fatty acids, glycerol, amino acids
D) amino acids, peptides, glucose

Question 8

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 9

A typical cell contains "powerhouses," which is another name for which of the following structures?

A) DNA
B) ribosomes
C) mitochondria
D) rough endoplasmic reticulum

Question 10

Which of the following CANNOT be formed from acetyl-coA molecules?

A) glucose
B) cholesterol
C) stearic acid
D) carbon dioxide

Question 11

Which of the following reactions is an example of an anabolic reaction?

A) pyruvate synthesis from glucose
B) acetyl-coA synthesis from cholesterol
C) carbon dioxide synthesis from citric acid
D) cholesterol synthesis from acetyl-coA molecules

Question 12

Which is the major energy carrier molecule in most cells?

A) ATP
B) glucose
C) pyruvate
D) water

Question 13

Which of these terms is specific to reactions in which simple compounds are combined into more complex molecules?

A) anabolic
B) catabolic
C) ergogenic
D) gluconeogenic

Question 14

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

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

Question 15

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

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

Question 16

The formation of glycogen by the liver cell is an example of which of these reactions?

A) oxidation
B) glycolysis
C) anabolism
D) catabolism

Question 17

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

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

Question 18

The site of lipid synthesis in the cell is which of these bodies?

A) nucleus
B) Golgi bodies
C) mitochondria
D) smooth endoplasmic reticulum

Question 19

Which of the following processes is an example of a catabolic reaction?

A) glucose formation from glycerol
B) urea formation from an amino acid
C) albumin formation from amino acids
D) palmitic acid formation from acetate

Question 20

Which of the following is among the functions of the liver?

A) excretion of urea
B) synthesis of the final active form of vitamin D
C) production of red blood cells
D) conversion of fructose to glucose

Question 21

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 22

What is the first product of fatty acid catabolism?

A) glycerol
B) pyruvate
C) acetyl-coA
D) triglycerides

Question 23

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

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

Question 24

Which of the following is an aspect of glycolysis?

A) It is irreversible.
B) It can occur only in the presence of oxygen.
C) It can occur only in the absence of oxygen.
D) It generates 2 molecules of pyruvate for each molecule of glucose.

Question 25

In which of the following groups can all of the dietary components be used to synthesize and store glycogen?

A) lactose, animal fats, wheat starch
B) animal fats, wheat starch, plant proteins
C) wheat starch, plant proteins, lactose
D) plant proteins, lactose, vegetable oils

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

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

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

Question 28

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

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

Question 29

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 30

Which of the following pathways from pyruvate is irreversible?

A) to glucose
B) to glucogenic amino acids
C) lactate
D) acetyl CoA

Question 31

Which of the following distinguishes aerobic metabolism from anaerobic metabolism?

A) Little or no oxygen is consumed.
B) Lactic acid is a major byproduct.
C) Energy is produced more slowly.
D) It yields energy for only short periods.

Question 32

The Cori cycle involves the interconversion of which of the following pairs?

A) lactate and glucose
B) glucose and amino acids
C) pyruvate and citric acids
D) fatty acids and acetyl-coA

Question 33

Fatty acid oxidation results in the direct production of which of these compounds?

A) ketones
B) fructose
C) pyruvate
D) acetyl-coA

Question 34

An aerobic reaction is one that requires which of the following components?

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

Question 35

Production of excessive amounts of acetyl-coA molecules leads to the synthesis of which of the following compounds?

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

Question 36

Which of the following groups contains only compounds that can be formed from metabolized glucose?

A) acetyl CoA, muscle glycogen, urea
B) acetyl-CoA, muscle glycogen, amino acids
C) acetyl CoA, amino acids, ammonia
D) acetyl CoA, muscle glycogen, ammonia

Question 37

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 of which of the following compounds?

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

Question 38

Which of the following series outlines the overall sequence of events in the complete oxidation of glucose?

A) Cori cycle, TCA cycle, glycolysis
B) glycolysis, TCA cycle, electron transport chain
C) electron transport chain, TCA cycle, Cori cycle
D) TCA cycle, electron transport chain, glycolysis

Question 39

Your roommate Demetrius is participating in a weightlifting course and complains of a burning pain during workouts. You explain to Demetrius that this is due to his muscles converting excess pyruvate to which of the following compounds?

A) lactate
B) glycerol
C) acetyl-coA
D) amino acids

Question 40

Approximately what percentage of the weight of triglycerides can be converted to glucose?

A) 5 percent
B) 10 percent
C) 20 percent
D) 30 percent

Question 41

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 42

In which of the following groups are the products all generated from the electron transport chain pathway?

A) CO_2, urea, water
B) urea, water, energy
C) water, energy, CO₂
D) energy, CO_2, urea

Question 43

When protein consumption is in excess of body needs and energy needs are met, what is the fate of the energy in the excess amino acid molecules?

A) stored as fat only
B) stored as glycogen only
C) stored as amino acids only
D) stored as glycogen and fat

Question 44

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) There are more potential pathways for disposal of carbohydrates than fats which reduce the efficiency.
B) The presence of oxygen in the corn oil molecule increases the potential for oxidation.
C) Fat contains more carbon-hydrogen bonds that can be oxidized
D) Because the energy content of corn oil is higher than sucrose, the energy cost of conversion into stored fat requires a smaller percentage of the nutrient's energy.

Question 45

After digestion and absorption, an amino acid NOT used to build protein will first be subjected to which of the following processes?

A) removal of its amino group
B) removal of its carboxyl group
C) hydrolysis of its peptide bond
D) condensation of its peptide bond

Question 46

Which of these is the immediate fate of excess dietary protein in the body?

A) storage
B) reduction
C) oxidation
D) deamination

Question 47

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

A) urea and acetone
B) gatty acids and glycerol
C) carbon, hydrogen, and oxygen
D) water, carbon dioxide, and energy

Question 48

Which of the following compounds can be formed from fatty acids?

A) ketones
B) glucose
C) amino acids
D) urea

Question 49

Approximately how many molecules of ATP are generated from the complete oxidation of 1 molecule of glucose?

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

Question 50

Which of the following processes leads to the production of urea?

A) oxidation of glucose
B) oxidation of amino acids
C) incomplete oxidation of fatty acids
D) synthesis of protein from amino acids

Question 51

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

A) fatty acids
B) acetyl-coA
C) amino acids
D) carbon dioxide

Question 52

In addition to energy, which of these components are the principal end products of cellular oxidation of carbohydrates?

A) water and carbon dioxide
B) carbon, hydrogen, and urea
C) indigestible fibre and nitrogen
D) monosaccharides and amino acids

Question 53

In which of the following groups can all of the dietary components be used to make body proteins?

A) glucose, glycerol, fatty acids
B) glycerol, fatty acids, amino acids
C) fatty acids, amino acids, glucose
D) amino acids, glucose, glycerol

Question 54

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 55

In which of the following groups are the products all generated via the TCA cycle or electron transport chain?

A) water, energy, ammonia
B) energy, ammonia, carbon dioxide
C) ammonia, carbon dioxide, water
D) carbon dioxide, water, energy

Question 56

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 57

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 which element?

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

Question 58

Approximately how many ATP molecules are synthesized from the complete oxidation of 1 molecule of palmitic acid?

A) 9
B) 27
C) 98
D) 129

Question 59

An immediate consequence of a cellular deficiency of oxaloacetate is a slowing of which of these reactions?

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

Question 60

In which of the following groups can all of the compounds serve as a precursor for oxaloacetate synthesis?

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

Question 61

Which of the following results in ketone formation?

A) lack of protein in the diet
B) partially oxidation of fats
C) excess acetoacetate in the diet
D) excess carbohydrate in the diet

Question 62

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

A) approximately 3 days
B) approximately 3 weeks
C) approximately 6 weeks
D) 2 to 3 months

Question 63

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

A) glycogen
B) fatty acids
C) amino acids
D) triglycerides

Question 64

What is the body's most likely response to surplus dietary fat?

A) The excess fat will almost all be stored as body fat.
B) The excess fat will promote increased fat oxidation.
C) The excess fat will spares breakdown of body proteins.
D) The greater the excess of dietary fat the lower the efficiency of fat storage .

Question 65

Which of the following conditions most likely results in acetone breath?

A) ketonemia
B) feasting syndrome
C) acetyl-coA toxicity
D) metabolic hormone imbalance

Question 66

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

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

Question 67

Assuming that other nutrient needs are met, what is the most efficient way to fatten a turkey?

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

Question 68

If an individual consumes dietary carbohydrate in excess of energy needs, what would be the first pathway for disposal of the carbohydrate? ,

A) fat synthesis
B) ATP synthesis
C) glycogen synthesis
D) protein synthesis

Question 69

Which of the following substances 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 70

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 which of the following occurrences?

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 71

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

A) protein
B) ketones
C) glycogen
D) triglycerides

Question 72

Which of the following reactions 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 73

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

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

Question 74

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 3 kg while exercising only briefly. Why hasn't Jake seen an increase in his biceps or abs?

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 otherprotein 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 75

Which of the following statements explains how excess carbohydrate intake contributes 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 76

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 kcal
B) 50 kcal
C) 75 kcal
D) 100 kcal

Question 77

Which of the following symptoms is most likely to be experienced by an individual who has developed ketosis?

A) lowering of blood pH
B) an increased appetite
C) a vinegar-like odour on the breath
D) weight gain

Question 78

Which of the following can be synthesized from all 3 energy-yielding nutrients?

A) lactate
B) glycogen
C) acetyl-coA
D) oxaloacetate

Question 79

The effects on metabolism from starvation are most similar to those from which of the following states?

A) fasting
B) feasting
C) a balanced reduced energy diet
D) physical activity energy expenditure in excess of dietary intake

Question 80

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 percent
B) 45 percent
C) 65 percent
D) 95 percent