Understanding Nutrition International Edition 13th Edition By Eleanor Noss Whitney – Test Bank
Chapter 6 – Protein: Amino Acids
1. What element is found in proteins but NOT in carbohydrates and fats?
2. In comparison to the composition of carbohydrates and fats, which element found in proteins makes them unique?
3. Which of the following is the primary factor that differentiates one amino acid from another?
a. The side group
b. The central carbon atom
c. The number of oxygen atoms
d. The number of nitrogen atoms
4. Which of the following elements is found in certain amino acids?
5. Which of the following terms is NOT used to classify amino acids in the diet?
c. Partially essential
d. Conditionally essential
6. How many different kinds of amino acids make up proteins?
7. Which of the following is NOT contained in an amino acid?
a. An acid group
b. An amino group
c. An aldehyde group
d. A central carbon atom
8. Approximately how many different amino acids are used in the synthesis of body proteins?
9. What is the simplest amino acid?
10. Which of the following is NOT an essential amino acid in human nutrition?
11. Any of the following can be used by the body for the synthesis of a nonessential amino acid EXCEPT
a. a fragment of fat.
b. an essential mineral.
c. an essential amino acid.
d. a fragment of carbohydrate.
12. What amino acid is classified as conditionally essential when dietary intake of phenylalanine is insufficient or the body cannot normally metabolize phenylalanine?
13. Which of the following is a feature of an essential amino acid?
a. It is not necessary in the diet
b. It must be supplied by the diet
c. It can be made from fat in the body
d. It can be made from glucose in the body
14. What type of reaction is required to bind two molecules of glycine together and release a molecule of water?
15. When two amino acids are chemically joined together, the resulting structure is called a
16. What is the composition of a tripeptide?
a. One amino acid with three carbons
b. Three amino acids bonded together
c. One amino acid with three acid groups
d. Three small protein chains bonded together
17. What is meant by the amino acid sequence of a protein?
a. Number of side chains in the protein
b. Folding arrangement of the peptide chain
c. Order of amino acids in the peptide chain
d. Order of only the essential amino acids in the protein
18. A dispensable amino acid is one that
a. is not needed by the body.
b. can be synthesized by the body.
c. can be used to synthesize an indispensable amino acid.
d. cannot be synthesized by the body because of a genetic defect.
19. In comparison to the well-defined structure of starch, which of the following is the most important factor that allows for the synthesis of thousands of different proteins?
a. Number of cell ribosomes
b. Number of different amino acids
c. Availability of amino acids containing sulfur
d. Availability of amino acids containing hydroxyl groups
20. Which of the following would be classified as a polypeptide?
a. 1 amino acid
b. 3 amino acids bonded together
c. 9 fatty acids bonded together
d. 20 amino acids bonded together
21. The following amino acids are linked together: glycine-lysine-valine. This compound is a
22. The weak electrical attractions within polypeptide chains account for the protein’s
a. primary structure.
b. secondary structure.
c. tertiary structure.
d. quaternary structure.
23. Which of the following is a feature of hemoglobin?
a. It has no tertiary structure
b. It holds the mineral calcium
c. It is constructed of 4 polypeptide chains
d. It has no primary or secondary structure
24. An example of a protein with quaternary polypeptide structures is
d. disulfide bridges.
25. What is the process by which heat or acidity disrupts the normal shape of a protein chain?
26. The application of heat or acid to a protein that causes its shape to change is known as
27. What process results in the hardening of an egg when it is exposed to heat?
d. Protein interaction
28. After a hamburger is eaten, in what organ is the hydrolysis of its proteins initiated?
c. Small intestine
d. Large intestine
29. What is the name of the inactive form of the protein-splitting enzyme in the stomach?
30. In what organ is pepsin active?
c. Small intestine
d. Large intestine
31. What digestive enzyme would be most affected in people who are unable to produce hydrochloric acid?
c. Pancreatic protease
d. Intestinal peptidase
32. Protein-hydrolyzing enzymes are commonly known as
33. The function of a protease is to
a. hydrolyze proteins.
b. synthesize proteins.
c. hydrolyze ribosomes.
d. synthesize ribosomes.
34. What is the chief function of pepsin?
a. Emulsifies dietary proteins
b. Activates hydrochloric acid
c. Activates pancreatic proteases
d. Cleaves proteins into smaller polypeptides
35. What percentage of dietary protein is hydrolyzed in the mouth?
36. After digestion of proteins, what products are absorbed into the circulation?
a. Free amino acids only
b. Free amino acids and oligopeptides
c. Free amino acids and dipeptides only
d. Free amino acids, and a few dipeptides and tripeptides
37. What is the usual fate of orally ingested enzyme supplements?
a. Digested by gastrointestinal proteases
b. Rapidly degraded by salivary secretions
c. Mostly absorbed in original form from the stomach
d. Completely absorbed in original form from the jejunum
38. Which of the following statements is NOT characteristic of enzymes?
a. They are all catalysts
b. They have a protein structure
c. They can be destroyed by heat
d. They are involved in synthesis reactions only
39. Which of the following describes the structure of pepsin?
c. Nucleic acid
40. All of the following are fates of amino acids within the small intestine EXCEPT
a. some may be used for energy by the intestinal cells.
b. some may be used for synthesis of gastric protease.
c. some may be used for synthesis of proteins by the intestinal cells.
d. they may be transported across the intestinal cell membrane to the capillaries.
41. Of the following sources of amino acids, which would be best absorbed in normal, healthy people?
a. Whole proteins
b. Predigested proteins
c. Proteins from raw foods
d. Mixture of free amino acids
42. Your cousin Wanda was born with a genetic defect affecting her digestion, namely, a lack of intestinal villus tripeptidases and dipeptidases. Which of the following digestive processes would NOT take place?
a. Protein → oligopeptides
b. Peptides → amino acids
c. Amino acids → peptides
d. Polypeptides → tripeptides
43. Which of the following describes a process in protein synthesis?
a. The code to make a protein is carried by a strand of messenger RNA
b. The final step in completing the protein is carried out in the mitochondria
c. The function of transfer RNA is to assist in absorption of amino acids into the cell
d. The DNA binds to ribosomes and directs uptake of specific amino acids to form the peptide chain
44. Which of the following is a characteristic of protein synthesis?
a. Mitochondria are bound to DNA to initiate peptide bond synthesis
b. Messenger RNA is constructed from a DNA template to carry instructions
c. Hormones carry messages from RNA to DNA to direct peptide bond synthesis
d. RNA transfers up to 6 amino acids simultaneously to the mitochondria for peptide elongation
45. The process whereby messenger RNA is made from a DNA template is
d. ribosome assembly.
46. What is a ribosome?
a. A template for protein synthesis
b. A hard knot of subcutaneous protein mass
c. A structure upon which proteins are assembled
d. An antibody synthesized by specialized immune cells
47. Which of the following does NOT describe a feature of protein in nutrition?
a. The study of the body’s proteins in known as proteomics
b. Protein synthesis requires messenger RNA and transfer RNA
c. Most of the body’s thousands of proteins have been studied thoroughly
d. The synthesis of a protein by following the genetic code is known as gene expression
48. Your college dormitory roommate, James, told you that he’s had anemia for quite some time and that it’s from having abnormally-shaped hemoglobin. What type of anemia does James have?
a. Sickle-cell anemia
b. Macrocytic anemia
c. Iron-deficiency anemia
d. Low oxygen-carrying anemia
49. A common genetic variation which causes a change in the amino acid sequence in the structure of hemoglobin leads to the disease
d. sickle-cell anemia.
50. Which of the following is characteristic of sickle-cell anemia?
a. The disorder can be serious but not fatal
b. The disorder leads to depression of energy expenditure
c. The abnormal structure of the hemoglobin alters the shape of the red blood cell
d. The hemoglobin amino acid sequence is abnormal in all four of the polypeptide chains
51. What is the structure of an enzyme?
c. Nucleic acid
52. What protein is intimately involved in the formation of scar tissue in wound healing?
53. What type of protein would the body make in order to heal a wound?
54. What term signifies when a cell makes a protein under the directions of a gene?
a. Gene encoding
b. Gene expression
c. Protein secretion
d. Protein amplification
55. Which of the following is a characteristic of hormones?
a. Inactivate bacteria
b. Act as messenger molecules
c. Coordinate visual response
d. Act as buffers in the bloodstream
56. Which of the following do(es) NOT function as a transport protein?
57. What is the relationship between body proteins and water?
a. Proteins attract water
b. Water attracts proteins
c. Water degrades proteins
d. Proteins form polymers of water
58. Which of the following does NOT describe an association between protein nutrition and the body’s water balance?
a. Inadequate protein intake may lead to edema.
b. Insufficient protein synthesis by the liver may lead to edema.
c. Excessive protein losses by the kidney may lead to dehydration.
d. Excessive protein intake burdens the kidneys to excrete unused nitrogen.
59. The conditions known as acidosis and alkalosis refer to a disruption of the body’s
a. pH balance.
b. protein balance.
c. nitrogen balance.
d. endogenous metabolism.
60. Tissue swelling that results from water accumulating between cells is known as
61. Proteins, because they attract hydrogen ions, can act as
62. What function does a buffer perform?
a. Helps emulsify fats
b. Helps maintain a constant pH
c. Facilitates chemical reactions
d. Helps protect against plaque buildup
63. Which of the following processes is regulated primarily by the buffering action of proteins?
a. pH balance
b. Fluid balance
c. Blood clotting
d. Synthesis of visual pigments
64. How do sodium and potassium travel into and out of cells?
a. Antidiuretic hormone transports potassium and prodiuretic hormone carries sodium
b. There are specific transport proteins in the blood that deliver the minerals to the cell cytoplasm
c. The balance of insulin and glucagon determines the movement of these minerals into and out of cells
d. There are transport proteins within the cell membrane that pick up and release the minerals across the membrane
65. What is opsin?
a. An antigen
b. An antibody
c. A light-sensitive protein
d. A blood transport protein
66. Which of the following proteins inactivates foreign bacteria and viruses?
67. The body’s usual response to detection of antigens is to synthesize
d. whey protein.
68. Which of the following describes the structure of an antibody?
b. Small nucleic acid
c. Huge protein molecule
d. Large peptide molecule
69. Which of the following is involved in the clotting of blood?
70. Given that protein is 16% nitrogen, how many grams of nitrogen are contained in a 2500-kcalorie diet that provides 15% of the energy as protein?
71. Which of the following may be used to determine protein utilization?
b. Nitrogen balance
c. Amino acid pool
d. Supplementary value
72. When nitrogen taken into the body exceeds nitrogen losses, we say the person is in
a. a healthy state.
b. nitrogen equilibrium.
c. positive nitrogen balance.
d. negative nitrogen balance.
73. Which of the following defines protein turnover?
a. The sum of protein in food and the body
b. The sum of protein synthesis and degradation
c. The amount of protein absorbed from the diet
d. The amount of protein used to synthesize glucose
74. What is the amino acid pool?
a. The total amino acid content derived from a 24-hour dietary intake
b. A measure of the circulating essential amino acid levels available for protein synthesis
c. The total amount of free amino acids in the circulation destined for deamination and excretion
d. A mix of essential and nonessential amino acids derived from protein breakdown and dietary protein intake
75. Which of the following describes the state of nitrogen balance for a normal, healthy 35-year-old person who weighs 60 kg and consumes a diet that provides 75 g of protein and adequate energy?
b. Positive balance
c. Negative balance
d. Endogenous balance
76. The body’s amino acid pool consists of
a. essential amino acids only.
b. endogenous amino acids only.
c. nonessential amino acids only.
d. both essential and nonessential amino acids.
77. What is the nitrogen balance of a person who consumed a 3500-kcalorie diet containing 10% protein and excreted a total of 12 grams of nitrogen? (Protein is 16% nitrogen.)
a. 0 g
b. -3 g
c. -1 g
d. +2 g
78. Which of the following would describe the state of nitrogen balance of a person who ingested 16 g of food nitrogen and lost 19 g of nitrogen?
b. Positive balance
c. Negative balance
d. Exogenous balance
79. What is the usual state of nitrogen balance for healthy infants, children, and pregnant women?
80. What amino acid is used to synthesize the neurotransmitter serotonin and the vitamin niacin?
81. What is meant by protein turnover?
a. Nitrogen equilibrium
b. The antibody-antigen complex
c. The synthesis and degradation of body proteins
d. The secondary structure of proteins that initiates folding
82. What is the fate of excess dietary protein?
a. After absorption, the liver will store the extra amino acids
b. After absorption, the extra amino acids will be rapidly degraded
c. Digestion will be decreased by 30 to 60%, resulting in less absorption
d. After absorption, extra proteins will be synthesized and stored for use when protein intake returns to normal
83. When amino acids are deaminated, the immediate products are ammonia and often a
a. uric acid.
b. keto acid.
c. folic acid.
d. gluco acid.
84. Protein sparing in the body is best achieved when a person ingests
a. proteins of plant origin only.
b. proteins of animal origin only.
c. adequate levels of carbohydrate and fat.
d. mixed protein sources on alternate days.
85. A person who is starving is losing
a. fat only.
b. glycogen only.
c. glycogen and fat only.
d. glycogen, protein, and fat.
86. Which of the following illustrates a deamination reaction?
a. Removal of the amino group from an amino acid
b. Separation of an amino acid from a peptide chain
c. Addition of an amino group to form a new amino acid
d. Addition of an amino acid to form a larger peptide chain
87. Approximately how much urea (g) can be produced daily by the average adult?
a. 5 g
b. 50 g
c. 100 g
d. 250 g
88. Which of the following is the most likely side effect of a high-protein, low-carbohydrate diet?
b. Increased thirst
c. Nitrogen toxicity
d. Increased water retention in the body
89. Which of the following compounds does NOT contain nitrogen?
90. Which of the following is a consequence of excess protein intake?
a. Decreased excretion of calcium
b. Decreased size of the liver and kidneys
c. Increased production and excretion of urea
d. Increased protein storage by the liver and kidneys
91. Which of the following are precursors of urea synthesis?
a. All amino acids
b. Animal proteins only
c. Essential amino acids only
d. Nonessential amino acids only
92. What is the process whereby an amino group is combined with a keto acid to form an amino acid?
93. In the metabolism of amino acids for energy, what is the fate of the amino group?
a. Excreted as urea
b. Burned for energy
c. Stored in the liver
d. Converted to glucose
94. The body’s need for water increases on a diet high in
c. saturated fat.
d. unsaturated fat.
95. What is the most likely reason for a person to have abnormally high blood ammonia levels?
a. Liver dysfunction
b. Kidney dysfunction
c. Protein intake twice the RDA
d. Protein intake one-tenth the RDA
96. Jason is 35 years old and was recently diagnosed with 2 failing kidneys. He was advised to decrease the amount of protein he consumes. If Jason cheats by eating an 8-ounce steak for dinner tonight, shortly thereafter there would most likely be an increase in the urea levels of his
97. What is the most likely reason for having an abnormally high blood urea level?
a. Liver dysfunction
b. Kidney dysfunction
c. Protein intake twice the RDA
d. Protein intake one-tenth the RDA
98. A prominent result of transamination reactions is the synthesis of
a. essential amino acids.
b. nonessential amino acids.
c. neurotransmitters and hormones.
d. both nonessential and essential amino acids.
99. Your father, who has a high blood ammonia concentration, most likely has a poorly functioning
d. intestinal tract.
100. Your mother, who has a high blood urea content, most likely has a poorly functioning
d. intestinal tract.
101. A reference protein equals or exceeds the essential amino acid requirements of all of the following population groups EXCEPT
b. preschool aged children.
102. What is the percent digestibility of most plant proteins?
103. What is the percent digestibility of most animal proteins?
104. Which of the following food proteins has the best assortment of essential amino acids for the human body?
105. Which of the following is related to the quality of a food protein?
a. Essential amino acid balance
b. Nonessential amino acid balance
c. Total amino acids per gram of food
d. Quantity of nonessential amino acids that can be converted to glucose
106. What primary factor governs the quality of a food protein?
a. Fat content
b. Essential amino acid content
c. Complex carbohydrate content
d. Nonessential amino acid content
107. In the study of protein nutrition, what term describes the amount of amino acids absorbed from a given amount of protein consumed?
c. Complementary index
d. Comparative equivalence
108. Which of the following is NOT considered to be a source of high-quality protein in human nutrition?
109. Which of the following animal-derived proteins is classified as a poor-quality protein?
110. If the diet is lacking an essential amino acid, what will be the course of action?
a. Body cells will synthesize it
b. Protein synthesis will be limited
c. Health will not be affected as long as other nutrients are adequate
d. Proteins will be made but they will lack that particular amino acid
111. What is a “limiting” amino acid in a protein?
a. A nonessential amino acid present in high amounts, which inhibits protein synthesis
b. An amino acid of the wrong structure to be utilized for protein synthesis efficiently
c. An essential amino acid present in insufficient quantity for body protein synthesis to take place
d. An amino acid that limits the absorption of other essential amino acids by competing with them for transport sites within the GI tract
112. Which of the following could NOT be a limiting amino acid in the diet?
113. Gelatin is a poor-quality protein because it
a. lacks tryptophan.
b. lacks methionine.
c. is poorly digested.
d. is poorly absorbed.
114. Alberta is a 20 year old who has been a vegetarian for 3 years. She comes to you for advice after reading some material online by the Meat Promoters of America organization. One of their statements is: “…vegetarians are at risk for protein deficiency because they cannot consume all of the essential amino acids necessary for healthy individuals.” How should Alberta be advised?
a. She should consume dairy and egg products at every meal to protect herself against protein deficiency
b. She should avoid the “limiting” amino acids because they are limiting her ability to maintain proper protein status
c. Because the statement is basically true, she should consider eating small quantities of meat every day in order to avoid protein deficiency
d. Although many foods don’t provide all the essential amino acids individually, she could consume complementary proteins throughout the day, which would provide all the essential amino acids she needs
115. Which of the following is characteristic of protein nutrition in vegetarians?
a. Vegetarians in general must practice complementary protein nutrition
b. Most vegetarians should consume gelatin to ensure adequate tryptophan intake
c. Healthy vegetarians typically consume protein sources of very high digestibility
d. Most vegetarians eating a variety of foods need not balance essential amino acid intake at each meal
116. What is the Daily Value for protein based on a 2000-kcalorie intake?
a. 25 g
b. 50 g
c. 75 g
d. 100 g
117. What is complementary protein nutrition?
a. A dietary program that involves eating vegetable and animal proteins on alternating days
b. A strategy that combines plant proteins in the same day to improve the balance of essential amino acids
c. A technique developed specifically for the elderly that involves optimizing the ratio of protein intake to energy intake
d. A body process that involves synthesis of crucial proteins from amino acids made available by the breakdown of storage proteins
118. In general, the protein quality in grains would be most improved by the addition of a plant protein rich in
d. glutamic acid.
119. In general, the protein quality of legumes would be most improved by the addition of a plant protein rich in
d. glutamic acid.
120. Relative to animal proteins, which of the following amino acids is present in lesser amounts in proteins of legumes?
d. Glutamic acid
121. Excessive amounts of homocysteine in the blood are thought to increase the risk for
c. heart disease.
d. protein-energy malnutrition.
122. Which of the following amino acids has been reported to lower blood pressure and reduce homocysteine levels?
123. Which of the following is NOT among factors known to raise homocysteine levels?
a. High folate intake
b. Smoking cessation
c. Arginine consumption
d. Excess alcohol intake
124. Which of the following is a feature of homocysteine?
a. It is found only in animal foods
b. It is a risk factor for osteoporosis
c. It is increased in the blood of coffee drinkers
d. It is increased in the blood of vitamin C-deficient people
125. Which of the following describes a relationship between protein/amino acids and heart disease?
a. Substituting soy protein for animal protein raises blood cholesterol levels
b. High blood levels of the amino acid arginine are a risk factor for atherosclerosis
c. High levels of homocysteine in food promote elevation of blood low-density lipoproteins
d. Elevated blood homocysteine levels are associated with smoking cigarettes and drinking alcohol
126. What ratio (mg:g) of calcium to protein intake is believed to promote optimal bone health?
127. Which of the following describes an association between protein intake and kidney function?
a. Low-protein diets increase the risk for kidney stone formation
b. Restricting protein intake may slow the progression of kidney disease
c. High protein intakes over the long term represent a risk factor for kidney disease
d. Liberal protein intakes result in high urea production, which increases the long-term efficiency of the kidneys
128. Based on the range of protein intake as a percentage of energy intake, what would be the highest safe level of protein intake for a 60-kg adult ingesting 2500 kcalories?
a. 48 g
b. 96 g
c. 120 g
d. 219 g
129. Which of the following describes a relationship between protein intake and calcium metabolism?
a. Calcium excretion falls with increasing intake of animal-derived proteins
b. Calcium excretion rises with increasing intake of animal-derived proteins
c. Calcium absorption declines with higher intakes of plant-derived proteins
d. Calcium absorption increases with higher intakes of animal-derived proteins
130. What is the RDA for protein for a 48-kg woman?
a. 24 g
b. 34 g
c. 38 g
d. 40 g
131. What is the actual ratio of calcium to protein intake (mg to g) for most U.S. women?
132. What would be the primary principle of wise diet planning as related to protein nutrition?
c. Nutrient density
d. kCalorie control
133. Which of the following is a feature of the protein RDA?
a. The recommendations are generous
b. It is highest proportionately for adult males
c. It is established at 8 grams per kilogram of ideal body weight
d. An assumption is made that dietary protein is from animal sources only
134. If protein needs are expressed per kilogram of body weight, which of the following describes the requirements of infants?
a. Less than adults
b. Similar to adults
c. Greater than adults
d. Less than adolescents
135. What is the range of daily protein intake, in g/kg, recommended for athletes by fitness authorities?
136. Your friend Jill has just joined her community college soccer team. How much protein should she consume each day?
a. 0.8 g/kg
b. up to 1.0 g/kg
c. 1.2-1.7 g/kg
d. 2.5-2.9 g/kg
137. Which of the following is an assumption made in the formulation of the RDA for protein?
a. Dietary protein is of high quality only
b. Dietary protein is of animal origin only
c. Dietary carbohydrate and fat intakes are adequate
d. Dietary protein should represent 12% of total energy
138. All of the following assumptions are made by the committee in setting the RDA for protein EXCEPT
a. adequate kcalories will be consumed.
b. protein eaten will be of mixed quality.
c. the fat content of the diet will be high.
d. other nutrients in the diet will be adequate.