Deck 27: Principles of Nutrition I and II

Question 1

The active hormone derived from vitamin D₃ is

A) produced in the skin.
B) hydroxylated in the 1 and 25 positions.
C) dependent on sunlight.
D) supplied in the diet.
E) required for urinary Ca²⁺ excretion.

Answer 1

hydroxylated in the 1 and 25 positions.

Question 2

All of the following is/are fat soluble vitamin(s) EXCEPT which one?

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

Answer 2

vitamin C

Question 3

The metabolic energy content of fat is approximately

A) 3 Cal/gm
B) 5 Cal/gm
C) 7 Cal/gm
D) 9 Cal/gm
E) 11 Cal/gm

Answer 3

9 Cal/gm

Question 4

Three nutritionally essential amino acids which tend to be deficient in plant proteins are:

A) lysine, arginine and threonine
B) methionine, lysine and tyrosine
C) tryptophan, methionine and lysine
D) tryptophan, lysine and leucine
E) lysine, leucine and tyrosine

Question 5

Which of the following is a coenzyme form of vitamin B₆?

A) nicotinamide adenine dinucleotide
B) flavin adenine dinucleotide
C) thiamine pyrophosphate
D) pyridoxal phosphate
E) tetrahydrofolic acid

Question 6

Which of the following statements about vitamin K is correct?

A) Vitamin K is obtained commercially from rats.
B) It is a water soluble vitamin.
C) It is a cofactor for an enzyme which carboxylates glutamate residues in proteins.
D) When bound to activated prothrombin, vitamin K provides a binding site for calcium ions.
E) When in the diet, it enhances the uptake of iron.

Question 7

Tetrahydrofolate is involved in the de novo synthesis of

A) adenylic acid.
B) thymidylic acid.
C) guanylic acid.
D) all of the above.
E) none of the above.

Question 8

Pyridoxal phosphate is involved in

A) oxidation-reduction reactions.
B) carboxylation reactions.
C) decarboxylation reactions.
D) aminotransferases.
E) none of the above

Question 9

All of the following statements about the vitamin D-regulated of calcium ions are true EXCEPT

A) ergocalciferol is normally converted to cholecalciferol in a reaction requiring ultraviolet light.
B) irradiated ergosterol is added to commercial milk because it can replace cholecalciferol.
C) cholecalciferol is 25-hydroxylated in the liver.
D) hydroxycholecalciferol is further hydroxylated in kidney to form the active hormone.
E) excess vitamin D can lead to hypercalcemia, which in turn can result in calcification of soft tissue.

Question 10

The percentage of the total dietary protein amino acids present in the typical American diet which is actually required for body maintenance is (in an adult):

A) 5% or less
B) 10% or less
C) 50% or less
D) 50 to 80%
E) 8 to 9%

Question 11

The most active form of vitamin D, 1, 25-dihydroxycholecalciferol, is synthesized from its precursor,25 -hydroxycholecalciferol, in

A) the kidney.
B) the liver.
C) the skin.
D) the intestinal mucosa.
E) plants. It must be supplied to humans in the diet.

Question 12

Which compound is NOT an immediate participant in the urea cycle?

A) argininosuccinate
B) citrulline
C) ornithine
D) arginine
E) succinate

Question 13

Which of the following vitamins can be accurately described as being a steroid hormone?

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

Question 14

Vitamin B₁₂ contains

A) copper.
B) cobalt.
C) cadmium.
D) chromium.
E) None of the above.

Question 15

Vitamin A can be synthesized in the body from the dietary provitamin form

A) beta carotene
B) 11-cis-retinal
C) cholesterol
D) 11-cis-retinol

Question 16

Thiamine deficiency results in accumulation of which of the following metabolites in the blood?

A) citrate
B) glycerol
C) pyruvate
D) glucose
E) carbon dioxide

Question 17

Cobalamin is a coenzyme which is required for the metabolic conversion in animals of

A) Glycine to serine.
B) Valine to propionyl CoA.
C) Homocysteine to methionine.
D) all of the above.
E) B and C only.

Question 18

The activation of trypsinogen to form trypsin in the small intestine is carried out by

A) pepsin.
B) enteropeptidase.
C) carboxypeptidases.
D) elastase.
E) ribonuclease.

Question 19

The role of most vitamins in metabolism is

A) to serve as coenzymes or precursors of coenzyme.
B) to serve as precursors of essential amino acids.
C) to serve as key intermediates in the citric acid cycle.
D) to build up resistance to bacterial and viral infections.
E) To spark metabolism.

Question 20

Which of the following is not a water-soluble vitamin?

A) vitamin C
B) thiamine
C) riboflavin
D) vitamin D
E) vitamin B₁₂

Question 21

Parathyroid hormone (PTH)

A) is secreted in response to above normal Ca²⁺ levels in the plasma
B) is secreted in response to below normal phosphate levels in the plasma
C) acts on the liver to promote hydroxylation of vitamin D
D) acts to raise plasma Ca²⁺ to normal by stimulating Ca²⁺ reabsorption from the kidney tubule
E) acts to lower plasma Ca²⁺ and phosphate by stimulating absorption from the gut

Question 22

Vitamin E functions primarily as:

A) a promoter of calcium absorption from the intestine.
B) an antioxidant in the plasma membrane.
C) a cofactor in generation of blood clotting factors.
D) a promoter of human fertility.
E) a coenzyme involved in intermediary .

Question 23

The most abundant lipid in the average diet is

A) steroid.
B) glycerol.
C) triacylglycerol
D) fatty acid.
E) none of the above.

Question 24

All of the following statements concerning vitamin A are correct EXCEPT

A) in humans, retinol, retinal and retinoic acid are completely interconvertible
B) the intestinal mucosa can convert beta-carotene to retinol
C) retinol is transported by a specific plasma protein
D) a cis isomer of retinal is involved in the visual process
E) the liver is the main storage site for retinol and retinol esters

Question 25

Which one of the following affects the absorption of calcium?

A) 25-hydroxycholecalciferol
B) 25-hydroxyergocalciferol
C) 7-dehydrocholesterol
D) calcitriol
E) colestipol

Question 26

Faulty connective tissue is caused by a deficiency of

A) Riboflavin
B) vitamin B
C) vitamin B6
D) vitamin C
E) Zinc

Question 27

The formation of vitamin D (cholecalciferol) from -dehydrocholesterol requires

A) a photochemical step.
B) a hydroxylation in kidney.
C) a hydroxylation in liver.
D) hydroxylation in both kidney and liver.
E) ingestion of 1,25 dihydroxycalciferol.

Question 28

The requirement for fat in the diet

A) would best be satisfied by supplying 30% of the calories as polyunsaturated fatty acids.
B) includes a requirement for cholesterol.
C) includes a requirement for the essential fatty acids and sufficient fat to permit absorption of the fat-soluble vitamins.
D) is not for any specific kind of fat but for enough fat to meet caloric requirements.
E) does not distinguish between saturated fatty acids and polyunsaturated fatty acids.

Question 29

Which vitamins participate, in coenzyme form, in reactions of the tricarboxylic acid cycle?

A) pyridoxine and thiamine
B) niacin and ascorbic acid
C) riboflavin and niacin
D) pantothenic acid and folic acid
E) thiamine and biotin

Question 30

All of the following statements about calcium are correct EXCEPT

A) Cytosolic calcium concentration is lower than that of extracellular fluid.
B) Calcium is the primary stimulator of parathyroid hormone secretion.
C) Calcium directly regulates 25-hydroxyvitamin D3-1-alpha- hydroxylase activity.
D) Mammalian biosynthesis of phosphatidylserine is calcium dependent.
E) A decrease in the plasma calcium concentration results in decreased calcitonin secretion.

Question 31

Which of the following may result from obesity?

A) elevation of serum free fatty acids, cholesterol, and triacylglycerols
B) fewer insulin receptors
C) increased lipase activity
D) high fasting blood sugar levels
E) all of the above

Question 32

Which of the following hormones is released in response to low plasma calcium?

A) Aldosterone
B) Calcitonin
C) PTH
D) Thyroid stimulating hormone
E) Thyroid hormone

Question 33

Which one of the following organs is considered to be the main storage site for vitamin A in the body?

A) Skin
B) Intestinal tract
C) Liver
D) Blood

Question 34

When an individual is found to be in negative energy balance,

A) appropriate vitamin supplements are usually sufficient to correct the condition.
B) the individual gains weight as a result of using less than a normal amount of energy.
C) the caloric content of the food ingested is less than the measured energy output.
D) too little energy has been expended in the maintenance of a normal body temperature.

Question 35

The largest reserve of metabolic energy in humans after triacylglycerols is in the form of

A) protein.
B) free glucose.
C) liver glycogen.
D) phospholipid.
E) muscle glycogen.

Question 36

The form of stored energy in man which is largest in terms of caloric yield per gram is

A) protein.
B) glucose.
C) glycogen.
D) triglyceride.
E) lipoprotein.

Question 37

Many vitamin E deficiency symptoms in experimental animals can be prevented by the administration of selenium. This is because

A) either selenium or vitamin E can function as a cofactor for glutathione peroxidase.
B) selenium prevents degradation of vitamin E in vivo.
C) selenium is a cofactor for glutathione peroxidase which, as does vitamin E, reduces intracellular hydrogen peroxide.
D) the conversion of vitamin E to its active form is dependent upon selenium.
E) the effects shown by selenium and vitamin E are, in reality, artifacts.

Question 38

Biotin deficiency would be expected to decrease

A) oxidation of palmitate.
B) gluconeogenesis from alanine.
C) lactic acid fermentation.
D) oxidation of pyruvate to CO₂.
E) ketone degradation.

Question 39

The most common symptom of iron deficiency is:

A) Abnormal clotting
B) Anemia
C) Dry skin
D) Night blindness
E) Spongy, swollen gums

Question 40

Dietary fiber

A) is a synonym for complex fats
B) may promote diseases like diverticulosis and cardiovascular disease
C) includes the simple carbohydrates
D) in very large amounts has no physiological effect
E) may be increased by increasing the consumption of fruits, vegetables and whole-grain cereal products

Question 41

Thiamine pyrophosphate is involved in

A) oxidation-reduction reactions.
B) carboxylation reactions.
C) decarboxylation reactions.
D) aminotransferases.
E) none of the above

Question 42

What is the major source of the fiber pectin?

A) Beans
B) Bran
C) Fruit
D) Oats
E) Whole wheat

Question 43

Which of the following is a coenzyme form of vitamin B?

A) Aquocobalamin
B) Cyanocobalamin
C) Transcobalamin
D) Methylcobalamin

Question 44

What red blood cell enzyme contains selenocysteine

A) GSH peroxidase
B) GSH reductase
C) Iodothyronine deiodinase
D) Succinate dehydrogenase
E) Thioredoxin reductase

Question 45

If a person increased his daily caloric intake, he would gain the most weight if those added calories were from:

A) Chicken
B) Fish
C) Oils
D) Pasta
E) Sugar

Question 46

The most common symptom of iron deficiency is:

A) Abnormal clotting
B) Anemia
C) Dry skin
D) Night blindness
E) Spongy, swollen gums

Question 47

Foods are not only sources of energy, but also serve as raw materials for the synthesis in whole or in part of bodily components. Listed below are foodstuffs and products derived from them. The list includes a pair which is NOT CORRECT. Which is the INCORRECT pair? FOODSTUFFS PRODUCTS

A) glucose ---> pentoses
B) glucose ---> arachidonic acid
C) tyrosine ---> thyroid hormone
D) cholesterol ---> cortisol
E) glycine ---> adenine

Question 48

Copper participates in all EXCEPT:

A) Amino acid metabolism
B) Cross linking collagen
C) Mobilizing iron
D) Phosphoryl transfer
E) Transferring electrons

Question 49

Poor nutrition in students presents first as:

A) Impaired performance
B) Shortness of breath
C) Skin lesions
D) Sleep disturbances
E) Weight gain

Question 50

In which of the following pairs of substances does one substance enhance the intestinal absorption of the other?

A) Iron - intrinsic factor
B) Calcium - vitamin D
C) vitamin B₁₂ - ferritin
D) Triglyceride - bile pigments
E) Biotin - avidin

Question 51

Because vitamin D and its derivatives in the body resemble steroids, the vitamin is handled in the same way as the steroid hormones. Select a process shared by vitamin D and the steroid hormones.

A) They are made in special cells in tissues derived from the same embryological origin.
B) Their active forms are bound to intracellular receptors in their target tissues.
C) Their most active forms contain only one oxygen atom per molecule.
D) Biosynthesis is under control of a tropic hormone from the anterior pituitary.
E) Like vitamin D, the steroid hormones can originate in food as active molecules.

Question 52

Which of the following results in a negative nitrogen balance?

A) Convalescence
B) Growth
C) Major trauma
D) Nursing
E) Pregnancy

Question 53

Tyrosine is not required in the diet of humans because we can synthesize it from

A) tryptophan
B) phenylalanine
C) lysine
D) histidine
E) methionine

Question 54

The form of vitamin A which is converted into rhodopsin in the visual cycle is:

A) B-carotene
B) retinol
C) retinal
D) 13-cis-retinoic acid
E) 11-cis-retinal

Question 55

Riboflavin is a part of a coenzyme involved in which type of reaction?

A) oxidation-reduction
B) transamination
C) decarboxylation
D) one carbon transfer
E) phosphorylation

Question 56

Which one of the following coenzymes contains cobalt as an essential constituent?

A) nicotinamide adenine dinucleotide
B) flavin mononucleotide
C) 5'-deoxyadenosylcobalamine
D) tetrahydrofolic acid
E) pyridoxal phosphate

Question 57

A positive nitrogen balance would be expected in all of the following conditions EXCEPT

A) growing children.
B) pregnancy.
C) consumption of a diet with increased protein.
D) recovery from trauma or surgery.

Question 58

Which one of the following mineral nutrients is not generally classified as a trace element?

A) molybdenum
B) chromium
C) magnesium
D) manganese
E) zinc

Question 59

Dietary deficiency disease caused primarily by insufficient protein intake is:

A) pellagra
B) PCM
C) starvation
D) kwashiorkor
E) scurvy

Question 60

All of the following are included under the heading of dietary fiber EXCEPT

A) cellulose
B) collagens
C) gums
D) lignins
E) pectins

Question 61

The requirement for fat in the diet

A) would best be satisfied by supplying 30% of the calories as polyunsaturated fatty acids.
B) includes a requirement for cholesterol.
C) includes a requirement for the essential fatty acids and sufficient fat to permit absorption of the fat-soluble vitamins.
D) is not for any specific kind of fat but for enough fat to meet caloric requirements.
E) does not distinguish between saturated fatty acids and polyunsaturated fatty acids.