Exam #2 Nutrition

Question 1

Plants use carbon dioxide, water, and the sun’s energy in the process of photosynthesis to synthesize

Answer 1

carbohydrate.

Plants synthesize carbohydrate via photosynthesis. Fat and protein are produced by other metabolic processes in the plants. Living plants do not usually produce alcohol, although stored fruit or grain may ferment and produce some alcohol.

Question 2

Fructose, galactose, and glucose are examples of

Answer 2

monosaccharides.

Fructose, galactose, and glucose each consist of a single unit of carbohydrate and are therefore monosaccharides. Disaccharides consist of two carbohydrate units; polysaccharides and complex carbohydrates consist of several carbohydrate units.

Question 3

Sucrose, maltose, and lactose are examples of

Answer 3

disaccharides.

Sucrose, maltose, and lactose each consist of two units of carbohydrate and are therefore disaccharides. Monosaccharides consist of one carbohydrate unit; polysaccharides and complex carbohydrates consist of several carbohydrate units.

Question 4

Glucose is a _____, often called _____ sugar.

Answer 4

monosaccharide; blood

Glucose is a monosaccharide and is the form of carbohydrate that travels in the blood, often called blood sugar. Glucose is not a disaccharide. Lactose is the disaccharide often called milk sugar.

Question 5

Compared with table sugar (sucrose), honey tastes _____ because it contains _____

Answer 5

sweeter; fructose

Honey is sweeter than table sugar because it contains fructose, the sweetest of all the sugars. Maltose is less sweet than table sugar and is not found in honey.

Question 6

Someone who follows a strict vegetarian (vegan) diet and eats very few refined foods is likely to have a _____ intake of _____ carbohydrates and dietary fiber.

Answer 6

high; complex

Strict vegetarian diets contain only plant foods that are high in carbohydrates. Refined foods contain more simple sugars and some starch. Unrefined foods contain mostly complex carbohydrates and fiber. Therefore someone who follows a strict vegetarian diet and eats very few refined foods is likely to have a high intake of complex carbohydrates and dietary fiber.

Question 7

Ketones are produced when insufficient _____ is available and the body has to metabolize _____ for energy.

Answer 7

carbohydrate; fat

Ketones are produced when insufficient carbohydrate is available and the body has to metabolize fat for energy. Ketones are intermediate products of fat metabolism that can build up and cause potentially lethal ketoacidosis. Ketones are not produced when protein is metabolized for energy

Question 8

Since the 1970s, consumption of refined white sugar has decreased, mostly because

Answer 8

use of high-fructose corn syrup has increased.

Use of refined white sugar has decreased because use of high-fructose corn syrup has increased. High-fructose corn syrup is used because it is cheaper to produce and sweeter. Unfortunately, consumers are not using less sugar; in fact, they are consuming more sugar overall. Use of artificial sweeteners, honey, and other natural sweeteners has increased, but this is not the main contributor to decreased refined white sugar consumption.

Question 9

The person who is most likely to develop dental caries is one who

Answer 9

snacks on candy bars between meals.

Dental caries is mostly likely to be caused by snacking on sweet, sticky foods (like candy bars) between meals. When desserts are eaten with meals, the teeth are exposed to carbohydrates for less time each day, so bacteria have less time to ferment the carbohydrate and cause caries. Soft drinks do not stick to the teeth like more sticky sweet foods and so are less likely to contribute to caries. Chewing gum may stimulate saliva production, which washes the teeth so it does not usually contribute to dental caries.

Question 10

Bacteria have a role with _____ in causing _____.

Answer 10

sugar; tooth decay

Bacteria ferment sugars in the mouth to cause tooth decay. Bacteria do not have a role in development of diabetes. Adequate intake of dietary fiber may help prevent diabetes. Intake of dietary fiber does not directly influence tooth decay, although foods high in dietary fiber may displace more sugary foods from the diet which would help prevent tooth decay.

Question 11

Sorbitol, mannitol, and xylitol are

Answer 11

sugar alcohols that provide 2-3 kcals/g.

Sorbitol, mannitol, and xylitol are sugar alcohols that provide 2-3 kcals/g. They do not have the same drug effect as noncarbohydrate alcohol that provides 7 kcals/g. They are carbohydrates, but do not provide 4 kcals/g. They are not artificial sweeteners and they do provide significant kcals.

Question 12

Aspartame should not be consumed by

Answer 12

individuals who have phenylketonuria (PKU).

Aspartame contains phenylalanine and so it should not be consumed by individuals who have phenylketonuria. There is no evidence that moderate intake of aspartame is harmful for infants and school-age children, although there may be no reason for them to consume it. Some individuals report that they get headaches after they consume aspartame, not everyone who gets migraines should avoid aspartame. Use of food sweetened with aspartame rather than sugar will provide fewer kcals and so will not help individuals gain weight, but this does not mean that for underweight people to avoid aspartame.

Question 13

Cellulose is an example of a(n)

Answer 13

insoluble fiber.

Cellulose is an example of an insoluble fiber. It is not soluble in water and it is not a protein.

Question 14

Diets low in fiber may increase the risk of

Answer 14

diverticular disease, constipation, and colon cancer.

A high intake of dietary fiber helps reduce the risk of diverticular disease, constipation, and colon cancer. Fiber intake is not related to risk of hip fracture, hypertension, or dementia.

Question 15

Eating a bowl of oatmeal for breakfast every day may help prevent _____ because it contains _____.

Answer 15

heart disease; soluble fiber

Oatmeal helps prevent heart disease because it contains soluble fiber that helps decrease blood cholesterol levels. It is not a significant source of potassium and is unlikely to affect blood pressure, except by displacing other foods high in sodium. Hypoglycemia is prevented by consuming foods that contain protein and carbohydrate throughout the day, rather than eating a specific food at one meal. Oatmeal would only contain a significant amount of calcium and vitamin D if it is made or eaten with milk and so would not necessarily help prevent osteoporosis.

Question 16

Athletes use physical training and dietary manipulation to increase their body stores of energy in the form of

Answer 16

glycogen.

Athletes use these methods to increase their body stores of energy in the form of glycogen. Glycogen is the form of carbohydrate stored in the liver and muscles. Glucose and amino acids are not stored in the body. Also, the primary function of amino acids is tissue building, not energy production. Short-chain fatty acids are produced when bacteria ferment dietary fiber in the colon. They are only used as an energy source by epithelial cells in the colon.

Question 17

After a high-carbohydrate meal, the dominant process would be

Answer 17

glycogenesis

After a high-carbohydrate meal, the carbohydrate will be digested and absorbed as glucose. Excess glucose will be converted to glycogen; this process is called glycogenesis. The other three processes would occur a long time after a meal, after a fast, or after exercise, when glucose stores are low. In glycogenolysis, glycogen is converted back to glucose. Gluconeogenesis is conversion of fat and protein to glucose. Production of the hormone glucagon increases blood glucose levels by stimulating glycogenolysis and gluconeogenesis.

Question 18

A fiber intake of 15 g daily would be considered to be _____ daily intake for dietary fiber.

Answer 18

below the optimal range of

A fiber intake of 15 g is below the optimal range of daily intake for dietary fiber. The recommended range is 20 to 38 g/day.

Question 19

Dietary fiber is fermented by

Answer 19

bacteria in the colon.

Dietary fiber is fermented by bacteria in the colon. Human enzymes (salivary and pancreatic amylase) cannot digest dietary fiber. By the time feces reach the rectum, they are largely solid and little fermentation takes place.

Question 20

The dietary intervention of increasing consumption of fruits and vegetables is most appropriate to relieve

Answer 20

constipation.

Foods high in dietary fiber, such as fruits and vegetables, can help relieve constipation by increasing fecal bulk. Vomiting is usually a response to a viral or toxic substance and is not relieved by specific foods. Fruits and vegetables may exacerbate diarrhea and are not directly related to osteoporosis.

Question 21

Most of the body’s energy intake should be supplied by

Answer 21

carbohydrates.

Most of the body’s energy should be supplied by carbohydrates. Fat provides an important, but lesser, source of energy. Protein can be used as an energy source if needed, but should not be the body’s primary energy source. Vitamins help the body obtain energy from carbohydrate, protein, and fat, but do not contribute energy themselves.

Question 22

An example of a food with a low glycemic index is

Answer 22

lentil soup.

Lentil soup would have a low glycemic index. A low glycemic index means that a food produces a relatively small increase in blood glucose level. Lentils are high in fiber which tends to decrease glycemic index. Bagels, sports drinks, and corn flakes are relatively low in fiber.

Question 23

Most carbohydrate digestion occurs in the

Answer 23

small intestine.

Most carbohydrate digestion occurs in the small intestine. Salivary amylase begins some carbohydrate digestion in the mouth, but this stops in the acid environment of the stomach. The stomach is the main site of protein digestion. Very little digestion takes place in the large intestine.

Question 24

Glucose is the preferred source of energy for the _____ systems.

Answer 24

brain and central nervous

Glucose is the main source of energy for the brain and central nervous system. Other body systems are able to use glucose or fat for energy.

Question 25

After a meal, insulin is the _____ that helps lower blood _____ levels.

Answer 25

hormone; glucose

Insulin is a hormone, not an enzyme. It lowers blood glucose levels after a meal by causing cells to absorb glucose from the blood. Glucagon is a hormone that has the opposite effect, causing blood glucose levels to rise when they start to fall between meals. Epinephrine is another hormone that increases blood glucose levels in response to acute stress. Blood does not contain sucrose.

Question 26

The type of diabetes that may be prevented by maintaining a healthy weight and exercising regularly is type _____ diabetes mellitus.

Answer 26

2

Type 2 diabetes mellitus may be prevented by maintaining a healthy lifestyle and weight. Type 1 diabetes is caused by autoimmune destruction of the pancreatic cells that produce insulin and is not affected by lifestyle. Type 3 and type 4 diabetes mellitus do not exist.

Question 27

The best way to ensure adequate nutrient intake is to eat plenty of

Answer 27

whole grains.

Whole grains supply the most nutrients. When grains are refined, the bran and germ are removed and many nutrients are fiber are lost. Enrichment replaces some, but not all, of the nutrients that are removed when grains are refined. Fiber supplements contain dietary fiber, but do not contain all the other vitamins and minerals found in whole grains.

Question 28

Diabetes mellitus (DM) is a disease caused by malfunctions in

Answer 28

carbohydrate metabolism.

Diabetes is a disorder of carbohydrate metabolism. Carbohydrate digestion is not impaired in individuals with diabetes and protein digestion and metabolism are not affected.

Question 29

A client has problems removing glucose from his blood because his pancreas no longer makes insulin. He has

Answer 29

type 1 diabetes mellitus.

If the client is not longer producing insulin, he has type 1 diabetes mellitus. Hypoglycemia is caused by erratic food intake or overproduction of insulin. Lactose intolerance is caused by inability to produce the enzyme lactase, which causes failure to digest lactose in milk. In type 2 diabetes, the pancreas still produces insulin, but the body’s cells are not able to use it properly.

Question 30

Weight loss and exercise are main features of the treatment for

Answer 30

type 2 diabetes mellitus.

Weight loss and exercise are the main features of treatment for type 2 diabetes mellitus. Hypoglycemia is treated by eating foods containing carbohydrate and protein at regular intervals throughout the day. Lactose intolerance is treated by avoiding intake of foods that contain large amounts of lactose or by taking pills that contain the enzyme lactase when these foods are eaten. Type 1 diabetes mellitus is treated by balancing food intake and insulin injections.

Question 31

The nutrient that provides the densest energy source is

Answer 31

fat.

Fat provides the densest energy source. Fat provides 9 kcal/g; protein and carbohydrate each provide 4 kcal/g; alcohol provides 7 kcal/g.

Question 32

Sex hormones, bile, and vitamin D are formed in the body from

Answer 32

sterols.

The body uses sterols to make sex hormones, bile, and vitamin D. Triglycerides are used for energy and stored fat. Phospholipids are important in cell membranes. Chylomicrons are the first lipoproteins formed after absorption of lipids from the blood.

Question 33

If a patient receiving fat-free parenteral nutrition develops eczema, the patient may have

Answer 33

essential fatty acid deficiency.

In a patient receiving fat-free parenteral nutrition, eczema may be a sign of essential fatty acid deficiency. Vitamin C deficiency is not affected by fat intake; symptoms include bleeding gums and breakdown of scar tissue. Eczema is not a sign of protein-energy malnutrition. The body makes phospholipids and sterol and so deficiency does not occur.

Question 34

Hydrogenation of vegetable oils _____ their shelf life and makes them _____ harmful to health.

Answer 34

increases; more

Hydrogenation of vegetable oils increases their shelf life because the double bonds are removed so the fatty acids are less vulnerable to oxidation. It also makes them more harmful to health because it forms trans fatty acids.

Question 35

A triglyceride is a compound composed of

Answer 35

glycerol with three fatty acids attached.

Triglycerides are compounds made up of glycerol and three fatty acids. Glycerol plus two fatty acids is a diglyceride. Glycerol does not combine with amino acids. Triglycerides do not form in triangular chains.

Question 36

A polyunsaturated fatty acid is a fatty acid with _____ bond(s) on the carbon chain.

Answer 36

two or more double

Polyunsaturated fatty acids have two or more double bonds on the carbon chain. Fatty acids with one double bond on the carbon chain are monounsaturated; those with no double bonds are saturated. Polyunsaturated fatty acids are vulnerable to oxidation, but this is not part of their structure.

Question 37

If a client wants to lose 1 lb of body fat each week, they would need to make sure that their daily calorie intake was lower than their daily energy needs by _____ kcals/day.

Answer 37

500

One pound of body fat contains 3500 kcals. To create a weekly deficit of 3500 kcals, daily energy intake would need to be less than daily energy expenditure by 3500 ÷ 7 = 500 kcals.

Question 38

In their natural form, most oils come from _____ products and most solid fats come from _____ products.

Answer 38

plant; animal

In their natural form, most oils come from plant products and most solid fats come from animal products. A few plant fats, such as coconut and palm oil, are naturally solid and a few animal fats, such as fish oil, are naturally liquid. Food processing may make fats more solid (by hydrogenation), but not necessarily. Some natural fats, such as butter and lard, are solid rather than liquid. Organic fats are not necessarily more liquid. Refining refers to processing grains to remove the bran and germ and does not affect the consistency of the oil.

Question 39

The number of double bonds present in the fatty acid chain determines the

Answer 39

degree of saturation or unsaturation of a fatty acid.

The number of double bonds in a fatty acid chain determines the degree of saturation or unsaturation of a fatty acid. The number of fatty acids attached to the glycerol molecule determines whether it is a monoglyceride (one fatty acid), diglyceride (two fatty acids), or triglyceride (three fatty acids). There is never more than one glycerol molecule attached to a fatty acid and glycerol molecules do not vary in their degree of saturation or unsaturation.

Question 40

By interfering with blood clotting, omega-3 fatty acids appear to lower the

Answer 40

risk of heart disease.

Omega-3 fatty acids help decrease risk of heart disease by preventing formation of clots that may block arteries that are narrowed by atherosclerotic plaques. Omega-3 fatty acids do not decrease blood pressure or serum levels of triglyceride and cholesterol.

Question 41

Overall energy intake can be greatly affected by relatively small changes in intake of

Answer 41

fat.

Fat contains more energy per gram than any other nutrient (9 kcal/g versus 4 kcal/g for protein and carbohydrate and 9 kcal/g for alcohol). Therefore, relative small increases or decreases in fat intake can result in significant increases or decreases in energy intake.

Question 42

The number of kcals provided by 23 g of fat is

Answer 42

207.

Fat contains 9 kcal/g. Therefore 23 g fat contain 23 × 9 = 207 kcals.

Question 43

If dietary analysis shows that fat provides 31% of an individual’s energy intake, their fat intake would be considered to be

Answer 43

within the recommended range.

The Acceptable Macronutrient Distribution Range for fat is 20% to 35% of kcals; therefore 31% is within the recommended range. “Generally recognized as safe” is a term used for food additives.

Question 44

Meat, dairy products, and nuts are major sources of _____ in the diet.

Answer 44

fat

Meat, dairy products, and nuts are major sources of dietary fat (even though some meats and dairy products can be very low in fat; overall these food groups contribute significant dietary fat). Nuts provide dietary fiber, but meat and dairy products do not. These foods contain some vitamins but are not considered major sources. Dairy products and nuts contain a little carbohydrate but meat is almost carbohydrate free.

Question 45

Hydrogenation is the process by which a liquid oil is made _____ solid and _____ stable.

Answer 45

more; more

Hydrogenation makes a liquid oil more solid and more stable by saturating the unsaturated fatty acids, making it more saturated.

Question 46

A client with coronary artery disease tells you that they always look for foods that are labeled “cholesterol free.” Foods with this label may still promote heart disease if they are high in

Answer 46

saturated fat and trans fat.

High intakes of saturated fat and trans fat increase blood cholesterol levels and contribute to coronary heart disease. Monounsaturated fat and polyunsaturated fat may slightly decrease serum cholesterol levels if eaten in moderation and so do hot promote heart disease. Intakes of medium chain triglycerides and cis fat are not directly related to heart disease.

Question 47

If a salad dressing is made with olive oil it would contain mostly _____ fatty acids.

Answer 47

monounsaturated

Olive oil is rich in monounsaturated fatty acids. Trans fatty acids are found in hydrogenated fats. Polyunsaturated fatty acids are found mostly in other liquid vegetable oils. Saturated fatty acids are found in dairy, meat fats, and coconut and palm oil.

Question 48

High levels of trans fatty acids are found in

Answer 48

vegetable oil shortening.

Trans fatty acids are found in vegetable oil shortening; they are formed when the liquid oil is hydrogenated to form a hard, stable fat. Vegetable oils, coconut and palm oil, and meats and dairy foods contain fat in the natural cis form.

Question 49

Antioxidants can be used to preserve fats without the addition of

Answer 49

hydrogen.

Antioxidants provide a way to preserve unsaturated fats without addition of hydrogen. Hydrogenation is used to stabilize and unsaturated fats. This process only adds hydrogen, not carbon, oxygen, or water.

Question 50

A special property of phospholipids that makes them valuable in foods and in the body is that they

Answer 50

are soluble in water and fat at the same time.

Phospholipids are valuable in foods and in the body because they are soluble in water and fat at the same time. This makes them useful emulsifiers and important components of cell membranes. Phospholipids have no particular role in carrying fat-soluble vitamins. They are not used as fat substitutes. They do not function as antioxidants.

Question 51

Most fat enters the lymphatic system after

Answer 51

absorption.

Most fat is absorbed into the lymphatic system from the small intestine. It then passes into the circulation. Therefore, circulation and metabolism occur after, not before, fat enters the lymphatic system. Hydrogenation occurs during food production and is not connected to processing of fat in the body.

Question 52

If a client has a total blood cholesterol of 246 mg/dL and a low-density lipoprotein cholesterol level of 172 mg/dL, their blood cholesterol level would be considered to be

Answer 52

high.

Total and LDL-cholesterol levels 240 and 150 mg/dL are considered high. Desirable total and LDL-cholesterol levels are 200 and 130 mg/dL, respectively; borderline high levels are 200-239 and 130-159 mg/dL, respectively.

Question 53

High levels of low-density lipoproteins are associated with an increased risk of

Answer 53

coronary artery disease.

High levels of low-density lipoproteins are associated with increased risk of coronary artery disease. They do not have a direct effect on risk of diabetes mellitus or high blood pressure and stroke. LDL and HDL levels are not necessarily related.

Question 54

The best way to decrease blood cholesterol level is to decrease dietary intake of

Answer 54

saturated fat.

The dietary factor that has the greatest impact on blood cholesterol levels is saturated fat intake because it causes the body to make more cholesterol. Cholesterol intake has less impact because most cholesterol is manufactured by the body. Blood cholesterol levels may be slightly inversely related to intake of monounsaturated and polyunsaturated fat.

Question 55

The client most likely to benefit from use of medium chain triglycerides is one who

Answer 55

has malabsorption because of removal of part of their small intestine.

Medium chain triglycerides are beneficial for patients with malabsorption because they are relatively easily absorbed. They do not contain essential fatty acids. They contain the same amount of energy as other fatty acids and so would not be especially beneficial for a client who needs to gain weight. They do not influence serum cholesterol levels.

Question 56

A good lunch choice for someone who wants to increase their intake of omega-3 fatty acids would be

Answer 56

tuna salad sandwich.

Fatty fish, such as tuna, are an excellent source of omega-3 fatty acids, so the tuna salad sandwich would be the best choice. Peanut butter and olive oil are high in monounsaturated fatty acids. Lentil soup is likely to be low in fat.

Question 57

Emulsification occurs so that dietary fat can be _____ by enzymes in the digestive tract.

Answer 57

broken down

Emulsification increases the surface area of fat droplets in the digestive tract so that they are more accessible to be broken down by enzymes.

Question 58

A substance that increases the solubility of fats to facilitate their digestion and absorption is

Answer 58

bile.

Bile increases the solubility of fats to facilitate their digestion and absorption. Stomach acid does not affect solubility of fats. Salivary lipase begins fat digestion but does not affect solubility. Glycerol is part of the structure of triglycerides, but does not increase their solubility.

Question 59

Overly restricting the fat intake of infants may lead to failure to thrive. Infants depend on dietary fat and cholesterol for formation of

Answer 59

brain and nerve tissue.

Infants need dietary fat and cholesterol for formation of brain and nerve tissue. Fat makes an important contribution to energy stores, but energy can be obtained from carbohydrate and protein. Bone formation is not dependent on dietary intake of fat and cholesterol.

Question 60

A client grew up on a farm and learned to prepare foods using butter and lard produced by the farm animals. She is now in her 60s and has just learned that she has coronary artery disease. To best meet her physical as well as psychologic needs, the health practitioner should

Answer 60

ask how she usually prepares foods and suggest ways to reduce the use of animal fat.

The health practitioner should start with the ways she usually prepares food and suggest ways she can use less animal fat and more heart-healthy unsaturated fats without making dramatic or arbitrary changes. A low-fat vegetarian dietary pattern is not necessary and is unlikely to be acceptable to the client. Eating more fruits and vegetables may be beneficial, but palm and coconut oil are high in saturated fat, which would not be helpful. It is probably not necessary for her to avoid adding any fat to foods and to eat only very lean poultry and fish; such drastic changes are unlikely to be maintained by the client.

Question 61

Protein is needed by the body because it provides

Answer 61

amino acids.

The body needs protein because it provides amino acids, needed to make all the proteins in the body. Excess protein can be used to provide energy, but the body does not need it for this purpose because it can obtain energy from carbohydrate and fat. Protein is made up of peptides, strings of amino acids joined together, but these are only needed by the body because of the amino acids they supply. Protein does not supply fatty acids.

Question 62

The amount of protein that most Americans eat is

Answer 62

more than we need.

Most Americans eat more protein than we need.

Question 63

In addition to carbon, hydrogen, and oxygen, amino acids also contain

Answer 63

nitrogen.

The amino groups in amino acids contain nitrogen. Amino acids do not contain potassium, iron, or sodium.

Question 64

Nine of the 20 amino acids are considered essential because they

Answer 64

cannot be manufactured by the body.

These amino acids are considered essential because they cannot be manufactured by the body and must be eaten in food. Some amino acids do contain sulfur, but this is not related to them being essential or nonessential. Essential amino acids are found in both animal and plant proteins. All amino acids, essential and nonessential, are used to make body proteins.

Question 65

Nonessential amino acids can be made by the liver using

Answer 65

other amino acids.

The body can make nonessential amino acids from other amino acids. Once the amino group has been removed from an amino acid and has been formed into urea, the body cannot turn it back into an amino acid. Fatty acids and glycerol cannot be used to make amino acids. Enzymes and hormones may help control the manufacture of nonessential amino acids but are not themselves used to make them.

Question 66

The secondary structure of proteins refers to the

Answer 66

straight, folded, or coiled shape of the amino acid chain.

The secondary structure of proteins refers to the straight, folded, or coiled shape of the amino acid chain. The combination of polypeptide chains is the quaternary structure. The sequence of amino acids in the chain is the primary structure. The strong bonds between loops of the chain is the tertiary structure.

Question 67

A client may be in a danger of their body proteins becoming denatured if they have a

Answer 67

very high fever.

Very high fever may denature body proteins, because the extreme heat changes the shape of the protein. Drug overdoses, vitamin deficiencies, and high stress levels do not denature proteins.

Question 68

The enzyme that begins digestion of protein in the stomach is

Answer 68

pepsin.

The enzyme that begins protein digestion in the stomach is pepsin. Renin is another enzyme secreted in the stomach in infants; it coagulates milk protein to keep it in the stomach longer to allow more time for digestion, but it does not begin protein digestion. Trypsin continues protein digestion in the small intestine. Peptidases are important in completing breakdown of peptides into amino acids.

Question 69

Loss of muscle tissue during recovery from a serious accident is an example of

Answer 69

catabolism.

During recovery from a serious accident, the physical stress and immobility cause loss of muscle tissue through catabolism. Anabolism occurs when new protein is being formed during growth or healing. Deamination is one part of catabolism; it refers to removal of the amino group when amino acids are broken down. Metabolism is a general term that includes both anabolism and catabolism.

Question 70

The vitamin that is essential for absorption of amino acids is

Answer 70

vitamin B6.

Vitamin B6 (pyridoxine) is needed as a carrier for absorption of amino acids. Folate, vitamin A, and vitamin E have other essential roles in the body, not related to protein absorption.

Question 71

An example of a situation in which positive nitrogen balance occurs is

Answer 71

pregnancy.

Positive nitrogen balance means that more nitrogen is retained in the body than is excreted. This would be the situation in pregnancy when new tissue is being formed in the mother and fetus. Aging, infection, and starvation are all times when the body would be in negative nitrogen balance.

Question 72

The main structural protein found in connective tissues, bone, and teeth is called

Answer 72

collagen.

The main structural protein found in connective tissues, bone, and teeth is called collagen. Fibrin is an important protein in blood clots. Albumin is an important blood plasma protein. Hemoglobin is the main protein that carries oxygen in the blood.

Question 73

Proteins that are produced by the immune system in response to specific foreign viruses and bacteria are called

Answer 73

antibodies.

Proteins that are produced by the immune system in response to viruses and bacteria are called antibodies. Hormones are chemical messengers in the body that are sometimes proteins. Enzymes are protein catalysts in the body. Lipoproteins are proteins that carry lipids in the bloodstream.

Question 74

An important role of proteins in the body includes

Answer 74

acid-base balance.

An important role of proteins in the body includes acid-base balance. Proteins do not have a major role in temperature regulation, conduction of nerve impulses, or elimination of waste products.

Question 75

The protein that carries oxygen in muscles is called

Answer 75

myoglobin.

The protein that carries oxygen in muscles is called myoglobin. Ferritin is a protein that carries iron in the bloodstream. Oxyglobin does not exist. Hemoglobin is a protein that carries oxygen in the bloodstream.

Question 76

Phenylketonuria is caused by

Answer 76

failure to break down excess phenylalanine.

Phenylketonuria is caused by failure to break down excess phenylalanine. It is a genetic disorder and is not caused by excessive intake of phenylalanine, inadequate intake of phenylalanine during pregnancy, or inability to digest proteins that contain phenylalanine.

Question 77

An example of a food that contains complete protein is

Answer 77

hard-boiled egg.

Eggs and most other animal foods contain complete protein. Grains, legumes, and nuts contain incomplete proteins.

Question 78

Incomplete protein

Answer 78

contains inadequate amounts of one or more essential amino acids.

Incomplete protein contains inadequate amounts of one or more essential amino acids. It still has nutritional value and may be combined with another incomplete protein to provide complete protein. Incomplete proteins are found mostly in plant foods. Denaturing proteins does not affect their amino acids content and make them incomplete.

Question 79

An example of a meal that contains complementary proteins is

Answer 79

split pea soup with crackers.

Split pea soup with crackers contains complementary proteins; the incomplete legume protein in the split pea soup complements the incomplete grain protein in the crackers. Vegetables such as tomato sauce and fruit such as strawberries do not contain sufficient protein to complement another incomplete protein in a meal. Oatmeal and toast are both grains and so their incomplete proteins are not complementary. Fruit yogurt contains complete protein and does not need to be combined with an incomplete protein.

Question 80

A measurement of the quality of food protein based on the amount that is retained in the body after digestion, absorption, and excretion is

Answer 80

biologic value.

The measurement of food protein quality that is based on the amount retained in the body after digestion, absorption, and excretion is biologic value. Amino acid score measures the amino acid content of a food compared with a reference protein. Protein efficiency ratio measures the effects of different proteins on weight gain in rats. Urinary urea excretion measures the amount of nitrogen excreted from the body; this includes nitrogen from breakdown of endogenous (body) proteins and exogenous (food) proteins.

Question 81

Men generally require more protein than women because they

Answer 81

have more lean body mass.

Men generally require more protein than women because they have more lean body mass than women; lean body mass requires more protein to maintain. Men are not necessarily more active than women. They do have a high metabolic rate, but this is because they have more lean body mass; their higher metabolic rate affects their energy needs, not their protein needs. Men do not use protein less efficiently than women.

Question 82

The protein needs of athletes are

Answer 82

higher than those of nonathletes.

Athletes have high protein needs than nonathletes (1.2 to 1.7 versus 0.8 g/kg, respectively). Most Americans consume the amount of protein recommended for athletes, so most American athletes do not need to increase their protein intake.

Question 83

The Recommended Dietary Allowance (RDA) for protein for a healthy adult who weighs 60 kg is _____ g/day.

Answer 83

48

The RDA for protein for a healthy adult is 0.8 g/kg per day. Therefore the RDA for an adult who weighs 60 kg is 0.8 × 60 = 48 g/day.

Question 84

A vegan diet contains

Answer 84

plant foods only.

Vegan diets contain only plant foods. Diets that contain mostly raw foods are macrobiotic diets. Diets than contain plant foods plus eggs are ovo-vegetarian diets. Diets that contain plant foods plus fish are pescetarian diets (these diets also usually include eggs and milk).

Question 85

Strict vegan diets may be associated with low intakes of

Answer 85

vitamins B12 and D.

Strict vegan diets do not contain any vitamin B12 (only found in animal products) and vitamin D (mostly obtained from fortified milk). Vegan diets contain plenty of carotenoids which the body can convert into vitamin A, and plenty of folate, vitamin C, vitamin E, and selenium.

Question 86

A Jew who follows a strict kosher diet would not eat

Answer 86

a cheeseburger and fries.

A Jew who follows a strict kosher diet would not eat a cheeseburger because they are not allowed to eat meat and dairy together. Macaroni and cheese and a bean and cheese burrito both contain only dairy. Roast beef with mashed potatoes is acceptable as long as the beef has been slaughtered appropriately.

Question 87

An appropriate size serving of meat, poultry, or fish is about the size of

Answer 87

the palm of your hand.

An appropriate size serving of meat, poultry, or fish is about the size of the palm of your hand. This represents about 3 ounces. A fist and one fourth of most dinner plates would make the serving size too large. A dollar bill is flat and therefore does not give a 3-dimensional serving size.

Question 88

Kwashiorkor is a type of malnutrition usually caused by

Answer 88

inadequate protein intake with adequate energy intake.

Kwashiorkor is usually caused by inadequate protein intake with adequate energy intake. Intake of incomplete protein sources could contribute to inadequate protein intake, but does not address the adequate energy intake found in kwashiorkor. Excessive intakes of protein and fluid would not cause malnutrition. Inadequate intakes of protein and energy cause marasmus.

Question 89

Examples of individuals who may have an increased risk of malnutrition include

Answer 89

children with chronic infections.

Chronic infection at any age and especially in childhood increases the risk of malnutrition because nutrient needs may be higher and nutrients may not be so well absorbed. Also appetite may be lower. Inactivity in middle-aged men is likely to lead to overnutrition, not undernutrition. Sleep-deprivation in adolescents is not associated with malnutrition. Breast-fed infants are usually well-nourished and are not at high risk for malnutrition.

Question 90

An example of the lifestyle habit of “chaining” is

Answer 90

eating a piece of fruit with a sandwich every lunchtime.

Eating a piece of fruit with a sandwich every lunchtime is an example of “chaining.” Chaining involves linking two behaviors; soon the individual will always want to eat a piece of fruit whenever they eat a sandwich. Gradually reducing intake of sugar-sweetened beverages, keeping a record of all food and beverages eaten, and involving all family members in choosing healthy foods are other good strategies to help improve eating habits.