Protein: The Cellular Foundation

MULTIPLE CHOICE

1. MyPlate recommends 3 oz of cooked lean meat, poultry, or fish daily. A small chicken drumstick or thigh is equivalent to 3 oz of meat.

a.
Both statements are true.
b.
Both statements are false.
c.
The first statement is true; the second is false.
d.
The first statement is false; the second is true.

ANS: B

MyPlate recommends 5.5 oz of cooked lean meat, poultry, or fish daily. A small chicken drumstick or thigh is equivalent to 2 oz of meat. As another visual cue, a deck of cards or the size of you palm equals approximately 3 oz.

REF: p. 91

2. A patient presents the following meal pattern of a typical day. This individual is most likely what type of vegetarian?

Breakfast

1 medium orange

cup oatmeal

cup sliced almonds

1 tsp margarine

1 cup soy milk

Lunch

1 cup cooked black beans

1 6-inch tostada

2 slices of tomato

1 leaf of lettuce

1 medium banana

1 cup soy milk

Dinner

1 cups bean soup

1 cup raw spinach leaves

1 slice rye bread

1 tsp margarine

1 cup pears

1 cup soy milk

a.
Vegan
b.
Lacto-ovovegetarian
c.
Ovovegetarian

ANS: A

This meal pattern indicates a vegan diet, which is the strictest form of vegetarianism. This diet contains only food from plants, including vegetables, fruits, and grains. No foods of animal origin are allowed (e.g., meat, milk, cheese, eggs, butter). Note the inclusion of margarine and soy milk. A lacto-ovovegetarian would consume dairy products. An ovovegetarian would supplement their diet with eggs.

REF: p. 96

3. The distinguishing feature of amino acids is the amine group. This nitrogen source is not present in carbohydrates, but is present in fats and many vitamins.

a.
Both statements are true.
b.
Both statements are false.
c.
The first statement is true; the second is false.
d.
The first statement is false; the second is true.

ANS: C

The amine group, which is the body’s source of nitrogen, is the distinguishing feature of proteins. It is not present in any other nutrient. The fundamental constituent of the protein molecule is called the side chain (R group).

REF: p. 87

4. The chemical structure of proteins is different from that of fats and carbohydrates because proteins contain nitrogen but not carbon.

a.
Both the statement and the reason are correct and related.
b.
Both the statement and the reason are correct but are not related.
c.
The statement is correct, but the reason is not correct.
d.
The statement is not correct, but the reason is correct.
e.
Neither the statement nor the reason is correct.

ANS: C

Like fats and carbohydrates, proteins also contain carbon, oxygen, and hydrogen. The distinguishing feature of proteins is the amine group, which is the body’s source of nitrogen. Note that proteins also contain a side group (R group) that is not present on carbohydrates and fats.

REF: p. 87

5. The type of vegetarian most at risk for nutrient deficiencies is the:

a.
vegan.
b.
lacto-ovovegetarian.
c.
ovovegetarian.
d.
pollovegetarian.
e.
semivegetarian.

ANS: A

Persons following a vegan diet, the most strict form of vegetarianism, may suffer from reduced intake of zinc, calcium, vitamins D and B12, and long-chain n-3 fatty acids. Vitamin B12 deficiency rates are especially high for pregnant women, adolescents, older adults, and those who have adhered to a vegetarian diet since birth.

REF: p. 96

6. Macaroni and cheese is an example of contributory proteins, because the deficiencies in amino acids of one component are offset by the adequacies of another.

ANS: D

The relationship between the two proteins in macaroni and cheese is called complementary. Without awareness, foods that complement each other are usually combined throughout the day. Other examples include beans with rice. Again, the higher quality protein in beans complements the protein deficiency in rice. Cereal and milk is another example of complementary proteins providing adequate amounts of essential amino acids.

REF: p. 96

7. Tissue building, maintenance, and repair are physiologic roles of proteins and carbohydrates, because both nutrients provide essential amino acids necessary for these functions.

ANS: E

Carbohydrates are not responsible for tissue building, maintenance, and repair. These physiologic functions are reserved for proteins. The primary role of carbohydrates is to provide energy; proteins also contribute to this function. Note that only proteins provide essential amino acids; carbohydrates do not. Also note that chemically the amino group distinguishes proteins.

REF: p. 87 | p. 88

8. The substance that is most supportive of bones and teeth is:

a.
hemoglobin.
b.
collagen.
c.
insulin.
d.
pepsin.

ANS: B

Collagen is a protein substance of connective tissue that helps to support body structures, such as skin, bones, teeth, and tendons. A low protein intake can affect all these functions.

REF: p. 89

9. An essential amino acid is essential for the body, but is not required in the diet. A nonessential amino acid is not essential for the body, but it contributes to protein formation in various ways.

a.
Both statements are true.
b.
Both statements are false.
c.
The first statement is true; the second is false.
d.
The first statement is false; the second is true.

ANS: B

An essential amino acid (EAA) is essential for the body and is required in the diet. Nonessential amino acids, although essential for the body, are not required in the diet because they can be produced from essential amino acids. Note that if any of the EAAs are unavailable when the cell needs them for protein synthesis, the protein cannot be produced.

REF: p. 88

10. Each of the following combinations of plant proteins creates a complete protein except one. Which one is the exception?

a.
Black beans and rice
b.
Peanut butter sandwich
c.
Macaroni and cheese
d.
French toast
e.
Cereal and cow’s milk

ANS: E

Although cereal and milk combine to create a complete protein, milk is not plant based. Of significance, MyPlate documents that milk is a good group that furnishes a significant portion of protein. Note that certain types of vegetarians, including vegans, would not include this combination in their diet.

REF: p. 88

11. Amino acids combine with each other to form polypeptides which are components of food and body proteins. The number of amino acids in a protein varies between 10 and 25, but each protein has a specific number.

a.
Both statements are true.
b.
Both statements are false.
c.
The first statement is true; the second is false.
d.
The first statement is false; the second is true.

ANS: C

The number of amino acids in a protein varies greatly from 100 to 300, with each protein having a specific number. Note that a polypeptide is composed of more than two amino acids, whereas a dipeptide contains only two amino acids.

REF: p. 88

12. Each of the following statements are true of the physiologic role of protein except one. Which one is the exception?

a.
The amount of essential amino acid furnished by a food determines its ability to support growth.
b.
Protein is present in muscle and connective tissue cells only.
c.
Body proteins are continuously being broken down and replaced.
d.
Amino acids and proteins are constituents of hormones, enzymes, and other body secretions.

ANS: B

Protein is present in every living cell, composing almost half of the dry weight of a cell. Second to water, protein is the most plentiful substance in the body.

REF: p. 89

13. During some food processing procedures, the amino acid lysine is bound to the protein within cereal. This fortification procedure increases bioavailability of protein from the cereal.

a.
Both statements are true.
b.
Both statements are false.
c.
The first statement is true; the second is false.
d.
The first statement is false; the second is true.

ANS: C

Binding the amino acid lysine to the plant protein during food processing actually makes the protein unusable by the body. This binding negatively affects bioavailability of the affected nutrient, in this case protein, and reduces its availability for use by the body after absorption. The protein remains intact and is absorbed, but it is not useful.

REF: p. 91

14. An edentulous patient dislikes eating meat. What substitutions could the dental hygienist suggest to provide the most protein intake?

a.
Milk
b.
Grains
c.
Fruits
d.
Vegetables

ANS: A

Together meat and dairy food groups furnish most of the recommended level of protein. Three cups of milk provide 24 g of protein and other essential nutrients. The dental hygienist should also consider that lower consumption of protein by older Americans may be related to cost, inability to prepare nutritious meals, depression, difficulty chewing, or concerns about the fat and cholesterol content of meat.

REF: p. 91

15. Poor nutrition results in delayed eruption and exfoliation of deciduous teeth and increased dental caries. Increased caries susceptibility in at-risk children may be related to changes in salivary composition caused by malnutrition.

a.
Both statements are true.
b.
Both statements are false.
c.
The first statement is true; the second is false.
d.
The first statement is false; the second is true.

ANS: A

Although children with malnutrition in both developing countries and developed countries have dietary habits that are not conducive to dental caries, there are several theories as to why caries rates are increased in these populations. Increased caries susceptibility may be related to numerous factors caused by malnutrition including alterations in structure of tooth crowns, diminished salivary flow, and altered salivary content.

REF: p. 93

16. Each of the following statements about protein-energy malnutrition (PEM) is true except for one. Which one is the exception?

a.
PEM is usually accompanied by other nutritional deficiencies.
b.
PEM affects the whole body.
c.
PEM during prenatal and postnatal stages can be reversed through proper nutrition during early childhood.
d.
PEM can be caused by impaired digestion or absorption of protein.

ANS: C

The occurrence of PEM during critical developmental stages, including prenatal and postnatal periods, can lead to irreversible changes affecting all tissues, including oral tissues. An example of an irreversible change is tooth development. Mild-to-moderate protein deficiency results in smaller molars, significantly delayed eruption, and retardation during development of the mandible.

REF: p. 93

17. Protein-energy malnutrition (PEM) may be responsible for increased incidence of noma and necrotizing ulcerative gingivitis (NUG), because these conditions are associated with depressed immune responses caused by nutritional deficiencies.

ANS: A

An increased incidence of noma and NUG has been observed, and it is thought that protein-energy malnutrition is a significant cause. These conditions are also associated with stress and infection, both of which correlate closely with malnutrition. Noma is a severe gangrenous process on the gingiva that can extend to the lips, cheek, and tissues covering the jaw. In the United States, nomalike lesions can occur in patients with cancer whose immune systems have been severely impaired by chemotherapy. NUG is characterized by degeneration and cellular death (necrosis) of the interdental papillae.

REF: p. 93

18. Each of following is a characteristic manifestation of necrotizing ulcerative gingivitis (NUG) except one. Which is the exception?

a.
Gingival erythema
b.
Necrosis of interdental papilla
c.
Marasmus
d.
Metallic taste and foul odor

ANS: C

Marasmus is a serious health problem in developing countries; it is not associated with NUG because it occurs in infants when protein and kilocalories are deficient in the diet. A similar disease, Kwashiorkor develops when young children receive adequate kilocalories, but not enough high-quality protein. Cardinal signs of NUG are severe gingival redness (erythema) and inflammation and necrosis of the interdental papilla. This painful gingivitis is generally accompanied by a metallic taste and foul odor or smell.

REF: p. 94

19. Analysis of a vegan’s diet reveals that the patient has not been consuming any vitamin B12. As an intervention, each of the following would be appropriate to suggest except one. Which one is the exception?

a.
Brewer’s yeast
b.
White chicken breast
c.
Soy-fermented tempeh
d.
Fortified breakfast cereal

ANS: B

Vegans, the most strict adherents to vegetarianism, exclude all foods of animal origin from their diets. The remaining selections would provide appropriate supplementation of vitamin B12.

REF: p. 96

20. If a low-quality protein is the only protein source ingested, it cannot support life or normal growth. High-quality proteins are well balanced in their essential amino acid content.

a.
Both statements are true.
b.
Both statements are false.
c.
The first statement is true; the second is false.
d.
The first statement is false; the second is true.

ANS: D

Low-quality proteins, if fed as the only protein source, support life, but not normal growth. These include proteins found in legumes, nuts, and grains. The amino acid in short supply relative to need is referred to as the limiting amino acid. Conversely, high-quality proteins are well balanced in their essential amino acid content.

REF: p. 88

21. The physiologic role of proteins includes all categories except one. Which one is the exception?

a.
Resistance to disease
b.
Regulation of fluid balance
c.
Energy
d.
Repair of tissue
e.
Primary source of energy

ANS: E

Although proteins provide energy, their primary physiologic role includes the remaining selections. Carbohydrates are the primary source of energy.

REF: p. 89

22. In most cases, digestibility and nutritional value are adversely affected by cooking procedures. Although cooking makes egg albumin more readily digestible, cooking soybeans decreases amino acid bioavailability.

a.
Both statements are true.
b.
Both statements are false.
c.
The first statement is true; the second is false.
d.
The first statement is false; the second is true.

ANS: B

Cooking favorably affects digestibility and nutritional value of most foods; this includes both egg albumin and soybeans. With cooking, egg albumin becomes more digestible, and soy bean bioavailability is increased. Bioavailability indicates the amount of nutrient available to the body after absorption.

REF: p. 91

23. Each of the following groups of individuals is susceptible to insufficient intake of protein except one. Which one is the exception?

a.
The elderly
b.
Individuals with low income
c.
Adults participating in endurance exercise
d.
Patients who are chronically ill

ANS: C

Additional dietary protein is unnecessary for healthy adults participating in endurance or resistance exercise; however, studies indicate that endurance- and strength-training athletes may need additional protein. Many factors make the elderly susceptible to insufficient protein intake including financial pressures, difficulty with food preparation, and dental issues. The dental hygienist can offer suggestions to the groups susceptible to protein deficiency that best suit their individual needs.

REF: p. 93

24. Each of the following is a manifestation of protein deficiency except one. Which one is the exception?

a.
Frequent or extended periods of fasting
b.
Medications that cause anorexia
c.
Abnormal food intake
d.
Oily hair

ANS: D

A classic manifestation of protein deficiency, in the presence of other symptoms, is dry, brittle hair that breaks easily. The skin and hair are also affected. The skin tends to tends to be dry and flaky, and the fingernails appear dry, cracked, and spoon-shaped.

REF: p. 93

25. Although it is controversial as to whether high-protein diets are excessive in content, scientific research has established each of the following facts except one. Which one is the exception?

a.
Less muscle is lost with higher protein diets.
b.
Satiation is increased.
c.
Thermogenesis is decreased.
d.
Energy efficiency is decreased.

ANS: C

High-protein diets appear to benefit weight control by increasing muscle mass, which burns more kilocalories; this increases thermogenesis (production of heat). Through these processes, satiation is increased and energy efficiency is decreased. Another aspect is that because protein increases satiety to a greater extent than carbohydrate or fat do, this can facilitate a reduction in ad libitum energy consumption.

REF: p. 95

26. Which food is most likely to contribute to protein deficiency?

a.
Milk
b.
Legumes
c.
Meat
d.
Cheese
e.
Eggs

ANS: B

Unless complemented by other sources, legumes, nuts, and grains are likely to contribute to protein deficiency because they are low-quality proteins. This category has at least one essential amino acid that is insufficient for optimal protein synthesis. If fed as the only protein source, low-quality proteins will support life, but normal growth cannot be supported. By contrast, high-quality proteins are well balanced in their essential amino acid content.

REF: p. 88

27. While counseling a patient who wishes to lose weight and eat a more healthy diet, a dental hygienist would recommend each of the following except one. Which one is the exception?

a.
Include two servings every day of food that supply n-3 fats.
b.
Calcium-fortified fruit juice counts as a calcium-rich food, but not as a serving in the fruit group.
c.
Adequate vitamin D can be obtained through sun exposure, fortified foods, or supplements.
d.
Eat a variety of protein foods including unsalted nuts and seeds.
e.
When possible, substitute beans for at least half of the meat in burritos, pasta, stir fry and the like.

ANS: B

Calcium-fortified fruit juice counts both as a calcium-rich food and toward servings from the fruit group. The remaining selections provide sound recommendations that are achievable by a motivated patient. Note that n-3 fats are also called omega-3 fatty acids. There are many options for protein recommendations that can be tailored to the preferences and lifestyle of the patient.

REF: p. 90 | Box 5-2

28. Sources of vitamin B12 include each of the following except one. Which one is the exception?

a.
Nutritional yeast
b.
Fortified soy milk
c.
Cow’s milk
d.
Eggs
e.
Walnuts

ANS: E

While walnuts enhance the diet by providing n-3 fats and other vitamins, they are not a source for vitamin B12.

REF: p. 99 | Box 5-3

29. Per kilogram of body weight, which group has the lowest RDA for protein?

a.
Infants
b.
Children
c.
Pregnant women
d.
Men

ANS: D

The RDA for men of all ages is lower than that for infants, children and pregnant women. Excluding pregnant and lactating women, the same is true for females.

REF: p. 90

30. In a 2-oz cooked serving, which food supplies the least protein?

a.
Light meat chicken
b.
Dark meat chicken
c.
Lean pork chop
d.
Lean cut of beef

ANS: B

A 2-oz serving of dark-meat chicken provides 18 g of protein, whereas light meat chicken, lean pork chop, and lean cut of beef provide 20, 19, and 19 g, respectively. Contrast this with a slice of enriched white bread, which provides 2 g of protein.

REF: p. 91

31. Patients with periodontal disease might require increased protein intake because the physiologic response to inflammation and infection can negatively affect protein synthesis.

ANS: A

Assessment of protein intake of patients with periodontal issues is important because protein deficiencies can compromise the physiologic systemic response to inflammation and infection. Periodontal problems can increase the protein requirement to promote healing.

REF: p. 91 | Dental Considerations

32. During protein deficiency, a decreased amount of protein in the blood causes an accumulation of fluids within the blood vessels because a loss of osmotic balance occurs.

ANS: D

Although a loss of osmotic balance occurs during a protein deficiency, the result is loss of fluid from the blood vessels. The disturbance in osmotic pressure causes fluids to leave the blood vessels and enter the tissue spaces, called interstitial spaces. This results in swelling, also called edema.

REF: p. 89

33. In patients with liver and kidney disease, increased levels of protein are recommended because these organs require continual cellular and tissue rebuilding that only protein can provide.

ANS: E

The liver and kidneys are heavily involved in protein metabolism and excretion of protein waste products. During disease within these organs, increased levels of protein would cause further stress and damage. Consequently, dietary protein is restricted in individuals with physiological disease that affects the liver or kidneys.

REF: p. 91

34. Prognosis for a protein-deficient patient undergoing periodontal surgery is reduced because excess nitrogen reduces the ability of the periodontium to withstand stress of surgery.

ANS: C

Protein deficiency results in a negative nitrogen balance that depletes nitrogen reserves. This further reduces blood protein levels and impairs the ability of the periodontium to withstand the stress of surgery. Additionally, the resistance of the periodontium to new or advancing infection is also impaired.

REF: p. 93

35. Each of the following is true of secretory immunoglobulin A (sIgA) except one. Which one is the exception?

a.
sIgA levels are depressed in malnourished children.
b.
sIgA is present is rarely found in the oral cavity.
c.
This secretion provides the first line of defense in the oral cavity.
d.
sIgA is present in nasal, intestinal and other mucosal secretions.

ANS: B

Secretory immunoglobulin A is the predominant immunoglobulin, or antibody, in oral, nasal, intestinal, and other mucosal secretions. It provides the first line of defense in the oral cavity. Low sIgA levels in malnourished children are thought to play a role in their increased susceptibility to mucosal infections.

REF: p. 93

36. The intake of 193 g/day of protein is the highest level recommended, because consumption above this level can jeopardize adequate intakes of nutrients form other food sources.

ANS: A

Using the rule of thumb that protein should provide 10% to 35% of caloric intake and based on consumption of 2200 kcal/day, 193 g of protein means that 35% of this individual’s diet is from protein. Because 35% is the upper limit, no more than 193 g of protein should be recommended.

REF: p. 91 | Dental Considerations