Deck 13: Micronutrients in Energy and Amino Acid Metabolism

Question 1

In the United States, salt can be purchased either with or without added iodide.

Answer 1

True

Question 2

Thiamin pyrophosphate (TPP), the coenzyme form of thiamin, is __________.

A)essential for the various oxidation-reduction reactions of the electron transport system
B)essential for the addition of two carbon fragments to fatty acids
C)essential for the oxidative decarboxylation of pyruvate
D)not really needed because our contemporary diets are low in carbohydrate

Answer 2

C

Question 3

In which of the following metabolic pathways are coenzymes required?

A)glycolysis
B)citric acid cycle
C)beta-oxidation
D)electron transport chain
E)All of these choices are accurate

Answer 3

E

Question 4

Approximately 90% of dietary manganese is absorbed and then transported by transferrin to the liver.

Question 5

Supplemental vitamin B-6, vitamin B-12, and folate can reduce blood levels of homocysteine, but have not been proven to reduce the risk of cardiovascular disease.

Question 6

Most B-vitamins function as __________.

A)fat-soluble vitamins
B)coenzymes
C)antibodies
D)sources of energy

Question 7

The best sources of thiamin in the average diet are ________.

A)pork products, whole or enriched grains and cereals, and legumes
B)root vegetables and cheddar-type cheese
C)whole grains and fresh fruit
D)ham and vegetables of the cabbage family

Question 8

A nutrient-dense source of thiamin is ________.

A)citrus fruits
B)milk and milk products
C)pork and pork products
D)leafy green vegetables

Question 9

Manganese plays a role in antioxidant defense as a part of the superoxide dismutase enzyme system.

Question 10

Riboflavin coenzymes function in a variety of metabolic pathways, such as __________.

A) beta-oxidation of fatty acids
B) the citric acid cycle
C) the electron transport chain
D)All of these choices are accurate.

Question 11

Although not classified as vitamins, ingestion of the substances taurine and carnitine is required for good health.

Question 12

Molybdenum functions as a cofactor for several enzymes in human metabolism.

Question 13

A good way to reduce risk of cardiovascular disease is to take supplements of vitamin B-6, vitamin B-12, folate, and vitamin
C.

Question 14

Which of the following foods represents the most nutrient-dense source of riboflavin?

A)low-fat milk
B)applesauce
C)whole wheat bread
D)green leafy vegetables

Question 15

Manganese deficiency and toxicity rarely have been reported in humans.

Question 16

Whole grains, nuts, legumes, and tea are the best sources of manganese.

Question 17

Thiamin should be given to an alcoholic patient who has ________.

A)pellagra
B)Wernicke-Korsakoff syndrome
C)pernicious anemia
D)scurvy

Question 18

Large doses of riboflavin are nontoxic.

Question 19

A deficiency of thiamin that affects the cardiovascular, muscular, nervous, and gastrointestinal systems is called ________.

A)megaloblastic anemia
B)pellagra
C)scurvy
D)beriberi

Question 20

The coenzyme form of riboflavin is ________.

A)TPP
B)ATP
C)FAD
D)NAD

Question 21

The fact that the amino acid tryptophan can be converted to niacin by the body explains why ________.

A)diets high in protein could prevent or cure pellagra
B)corn-based diets prevent pellagra
C)gelatin cures pellagra
D)alcoholics sometimes develop Wernicke-Korsakoff syndrome

Question 22

Niacin is necessary in the diet to prevent the disease called ________.

A)pernicious anemia
B)beriberi
C)scurvy
D)pellagra

Question 23

The B-vitamin most easily destroyed by exposure to light is ________.

A)biotin
B)niacin
C)riboflavin
D)thiamin

Question 24

Bright yellow urine usually is indicative that someone is supplementing with ________.

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

Question 25

The coenzyme forms of niacin include ________.

A)nicotinic acid and nicotinamide
B)FAD and FMN
C)NAD and NADP
D)ATP and FAD

Question 26

The riboflavin coenzymes have _______ functions in cellular metabolism.

A)antioxidant
B)chelating
C)oxidation and reduction
D)single carbon group transfer

Question 27

An excess intake of riboflavin either from diet or supplements is mainly ________.

A)excreted in the urine
B)excreted in bile and feces
C)stored in all body cells
D)stored in the liver

Question 28

A characteristic symptom of niacin deficiency is ________.

A)cracks at the corners of the mouth
B)a purple-red tongue
C)severe edema
D)inflammation of the skin after exposure to the sun

Question 29

The niacin coenzyme is reduced (NAD⁺ $\rarr$ NADH + H⁺) during ________.

A)glycolysis
B)the pyruvate decarboxylation reaction
C)the citric acid cycle
D)All of these choices are accurate

Question 30

Important contributors to niacin intake in the American diet are ________.

A)poultry, meat, and fish
B)citrus fruits, kiwi, and bananas
C)milk, cheese, and yogurt
D)spinach, kale, and broccoli

Question 31

Niacin can be obtained from foods as the vitamin itself (preformed niacin) or be synthesized ________.

A)from the B vitamin riboflavin
B)from the essential amino acid tryptophan
C)by bacteria in the large intestine
D)All of the above are correct

Question 32

A diet that provides 75 g protein per day can contribute __________ mg niacin from tryptophan.

A)25
B)7.5
C)12.5
D)<5 75 g protein x 10 mg tryptophan/g protein = 750 mg tryptophan
750 mg tryptophan / 60 mg tryptophan/mg niacin = 12.5 mg niacin

Question 33

A painful, red, inflamed tongue is called ________.

A)glossitis
B)cheilosis
C)stomatitis
D)anemia

Question 34

Which of the foods listed below has the lowest niacin bioavailability?

A)wheat
B)corn
C)almonds
D)spinach

Question 35

Thiamin, niacin, and riboflavin work together in important biochemical pathways that ________.

A)synthesize collagen
B)control the visual process
C)promote absorption of calcium
D)release energy from carbohydrate, fat, and protein

Question 36

An essential component of coenzyme A is ________.

A)biotin
B)pantothenic acid
C)thiamin
D)vitamin C

Question 37

The nutrient sometimes prescribed by physicians to increase HDL-cholesterol and lower triglyceride levels is ________.

A)thiamin
B)folic acid
C)niacin
D)None of these choices are accurate

Question 38

Adolescent girls with low dairy product intake often present with fatigue and anemia due to a deficiency of ________.

A)vitamin C
B)calcium
C)lactose
D)riboflavin

Question 39

In the average U.S.diet, 1/4 of the riboflavin comes from one food group, the ________.

A)fruit group
B)vegetable group
C)milk group
D)grains group
E)meat & beans group

Question 40

To protect riboflavin from destruction by sunlight, milk and milk products are packaged in ________.

A)clear glass bottles
B)paper and opaque plastic cartons
C)clear plastic bottles and cartons
D)any kind of container

Question 41

Symptoms of vitamin B-6 deficiency include ________.

A)depression, confusion, and convulsions
B)microcytic anemia
C)dermatitis
D)All of these choices are accurate

Question 42

Biotin is needed for ________.

A)gluconeogenesis
B)glutathione reductase
C)nicotinamide adenine dinucleotide
D)None of these answers are correct

Question 43

Pyridoxal, pyridoxine, and pyridoxamine are three forms of ________.

A)vitamin B-12
B)vitamin P
C)folic acid
D)vitamin B-6

Question 44

Pantothenic acid is a part of _________, an important biochemical compound.

A)pyruvate
B)citric acid
C)acetyl-CoA
D)homocysteine

Question 45

Research shows that supplemental vitamin B-6 may help women who are experiencing ________.

A)nausea associated with pregnancy
B)pellagra
C)premenstrual syndrome
D)depression

Question 46

The cells most sensitive to a deficiency of dietary folate are cells that ________.

A)have a short life span and rapid turnover rate
B)have to last a lifetime
C)function in the immune system
D)are classified as phagocytes

Question 47

Neurotransmitter synthesis requires the vitamin B-6 coenzyme.Which of the following is classified as a neurotransmitter?

A)norepinephrine
B)gamma-aminobutyric acid (GABA)
C)serotonin
D)All of these choices are accurate.

Question 48

Irreversible nerve damage may be caused by excessive intake of _______ supplements.

A)vitamin B-12
B)vitamin B-6
C)tryptophan
D)vitamin C

Question 49

Pyridoxal phosphate ________.

A)participates in reactions that synthesize non-essential amino acids
B)participates in reactions that synthesize essential amino acids
C)prevents premenstrual syndrome
D)is a natural oral contraceptive

Question 50

A high intake of raw egg whites (>12 per day) can inhibit absorption of ________.

A)folate
B)vitamin B-12
C)pantothenic acid
D)biotin

Question 51

In addition to its role in amino acid metabolism, vitamin B-6 is also required for ________.

A)fatty acid metabolism
B)the release of glucose from glycogen
C)the electron transport chain
D)glycolysis

Question 52

________ are very large immature red blood cells, which are formed as a result of folate deficiency.

A)Erythrocytes
B)Megaloblasts
C)Lymphocytes
D)Platelets

Question 53

Those most likely to experience a biotin deficiency are ________.

A)adolescents with low energy and, thus, low biotin intake
B)alcoholics with impaired biotin absorption
C)infants lacking an enzyme required for biotin absorption
D)All of these choices are accurate

Question 54

The protein in raw egg whites that can bind biotin is called ________.

A)avidin
B)salmonella
C)casein
D)keratin

Question 55

Biochemical reactions that add CO₂ to compounds often require ________.

A)folic acid
B)thiamin
C)biotin
D)vitamin B-12

Question 56

A defect in the formation of the neural tube during early fetal development can occur from a lack of ________.

A)biotin
B)folate
C)vitamin B-6
D)choline

Question 57

A major role of folate in cellular metabolism is the ________.

A)synthesis of steroid hormones
B)conversion of polyunsaturated fatty acids to saturated fatty acids
C)formation of glucose from galactose and fructose
D)synthesis of purine and pyrimidine bases in RNA and DNA

Question 58

In a dietary deficiency of folate, there are decreasing numbers of mature red blood cells to carry the oxygen from the lungs to the tissues.This condition is known as ________.

A)achlorhydria
B)megaloblastic anemia
C)ariboflavinosis
D)hemorrhagic disease

Question 59

A biochemical function of THFA (tetrahydrofolate) is ________.

A)transfer of NH₂ groups from amino acids to CO₂ to form urea
B)transfer of hydrogens and electrons through the various energy-yielding pathways
C)removal of CO₂ from various intermediates in the citric acid cycle
D)accepting or donating single-carbon molecules in various metabolic pathways

Question 60

To calculate the DFE for the diet, multiply total synthetic folic acid intake by ____; add that value to the total food folate.

A)1.7
B)2.5
C)4.0
D)None of these choices are accurate

Question 61

A strict vegan diet may lack ________.

A)vitamin B-12
B)vitamin C
C)vitamin A
D)niacin

Question 62

About 50% to 90% of folate in foods can be destroyed by ________.

A)food processing and preparation
B)ultraviolet light
C)oxidation
D)All of these choices are accurate

Question 63

Most of our dietary sulfur is supplied by ________.

A)protein-rich foods
B)carbohydrates
C)vitamins
D)lipids

Question 64

Vitamin B-12 is supplied mostly in ________.

A)fruits and vegetables
B)cereal grains
C)foods of animal origin
D)None of these answers are correct

Question 65

A major role of vitamin B-12 in cellular metabolism is ________.

A)transfer of a methyl group to the amino acid homocysteine, forming the amino acid methionine
B)transfer of a methyl group to the pyrimidine uracil, forming the pyrimidine thymine
C)in transamination reactions, allowing the synthesis of nonessential amino acids
D)as an electron acceptor, allowing function of the electron transport chain

Question 66

Intrinsic factor is produced by the ________.

A)beta-cells of the pancreas
B)salivary glands
C)parietal cells of the stomach
D)enterocytes of the small intestine

Question 67

Individuals most likely to experience poor vitamin B-12 status are ________.

A)elderly adults, due to atrophic gastritis
B)infants, due to low vitamin B-12 content in breast milk
C)athletes, due to high vitamin B-12 requirements
D)pregnant women, due to high vitamin B-12 requirements

Question 68

Choline is required for the synthesis of ________.

A)glycogen and many proteins
B)phospholipids and lipoproteins
C)homocysteine and methionine
D)collagen and connective tissue

Question 69

Pernicious anemia is treated most often by ________.

A)a diet high in milk and dairy products
B)regular intramuscular injection of vitamin B-12
C)oral supplementation of iron
D)eating liver three times a week

Question 70

The form of folate that is best absorbed is the ________.

A)monoglutamate form found in supplements and fortified foods
B)polyglutamate form found naturally in foods
C)reduced form found mainly in animal foods
D)oxidized form found mainly in plant foods
E)None of these answers, as all forms are absorbed equally well

Question 71

For vitamin B-12 to be absorbed, it must be attached to ________.

A)an incomplete protein
B)intrinsic factor
C)bile
D)the protein portion of its final coenzyme form

Question 72

Vitamin B-12 is absorbed in the ________.

A)stomach
B)duodenum
C)jejunum
D)ileum

Question 73

The compound carnitine is required for ________.

A)fatty acid synthesis
B)glycogen breakdown
C)active transport of compounds into cells
D)transport of fatty acids into mitochondria

Question 74

Which group of individuals is advised to consume 400 micrograms of folic acid daily from supplements and/or fortified foods?

A)infants
B)the elderly
C)athletes
D)women capable of becoming pregnant

Question 75

Which of the following factors can interfere with the absorption of vitamin B-12?

A)Surgical removal of the stomach
B)Defective R-protein synthesis
C)Infections of the ileum or surgical removal of the ileum
D)All of these choices are accurate

Question 76

Which group of individuals has the highest requirement for folate?

A)infants
B)adolescent males
C)pregnant women
D)the elderly

Question 77

It is very difficult to consume excess folic acid from nonprescription vitamin supplements because ________.

A)folic acid is never included in over-the-counter nutrient supplements
B)the FDA limits the amount of folic acid in supplements to 400 micrograms per capsule
C)folic acid in pill form imparts an unpleasant taste so that no one would ever attempt to take extra amounts
D)absorption of the vitamin is age-related.As we get older we automatically adjust the amount we absorb to more than the maximum level

Question 78

Megaloblastic anemia develops as a result of deficiencies of __________ and __________.

A)thiamin; riboflavin
B)vitamin B-6; folate
C)folate; vitamin B-12
D)vitamin K; folate
E)All of these choices are accurate

Question 79

Good sources of folate include ________.

A)enriched cereals and grains
B)leafy green vegetables
C)oranges
D)dried beans
E)All of these choices are accurate

Question 80

Rich sources of choline are ________.

A)enriched cereals and grains
B)fats and oils
C)meats, eggs, and dairy products
D)fruits and vegetables