Deck 6: The Proteins and Amino Acids

Question 1

Antibodies are identical large proteins in the blood that are effective in destroying multiple types of invading foreign particles.

Answer 1

False

Question 2

Many healthy people can consume less than the recommended amount of protein and still meet their bodies' protein needs.

Answer 2

True

Question 3

Vegetarians have significantly higher rates of hypertension than the general population.

Answer 3

False

Question 4

Sound nutrition authorities acknowledge that well-chosen vegetarian diets are consistent with good health and can meet nutrient needs.

Question 5

Which of the following accounts for the differences among the various amino acids?

A) the amine group
B) the side chain
C) the acid group
D) a and b
E) b and c

Question 6

The body is able to make all of the 20 amino acids needed from fragments derived from carbohydrate and fat.

Question 7

The body normally makes tyrosine from the essential amino acid:

A) phenylalanine.
B) leucine.
C) valine.
D) lysine.

Question 8

Overconsumption of protein-rich foods offers no benefits and may pose health risks, particularly for weakened kidneys.

Question 9

The growth of well-fed vegetarian children is similar to that of their meat-eating peers.

Question 10

Growing children are in negative nitrogen balance because they need more protein for adding blood, bone, and muscle cells.

Question 11

Legumes are a good source of protein, many B vitamins, iron, and other minerals, making them exceptionally nutritious foods.
Controversy 6 True/False Items

Question 12

Amino acid supplements are easy to digest and can relieve the digestive system from overworking.

Question 13

Which of the following is found in protein but not in carbohydrate or fat?

A) carbon
B) hydrogen
C) nitrogen
D) oxygen

Question 14

Each amino acid has its own distinctive chemical side chain attached to the center carbon of the backbone.

Question 15

Sickle-cell disease is an example of an inherited mistake in the amino acid sequence.

Question 16

Without critical essential amino acids to perform their roles, many of the body's life-sustaining activities would come to a halt.

Question 17

If needed, protein can help to maintain a steady blood glucose level and so meet the glucose needs of the brain.

Question 18

Some foods are so high in acid that they are capable of making the acid in the stomach even stronger.

Question 19

When a person ingests a large dose of any single amino acid, absorption of others of its type may be limited.

Question 20

For the majority of exercisers, adding excess protein or amino acid supplements to an adequate diet will stimulate muscle building.

Question 21

Which of the following is a protein catalyst, which facilitates chemical reactions?

A) hormone
B) antibody
C) lipoprotein
D) enzyme

Question 22

Proteins attract water and hold it within blood vessels, preventing it from freely flowing into the spaces between the cells. This is an example of how protein is used for:

A) supporting growth and maintenance.
B) building enzymes, hormones, and other compounds.
C) building antibodies.
D) maintaining fluid and electrolyte balance.

Question 23

The sequences of amino acids that make up a protein molecule are specified by:

A) age.
B) sex.
C) heredity.
D) the diet.

Question 24

The DRI for protein for healthy adults is _____ gram(s) per kilogram of body weight.

A) 0.5
B) 0.8
C) 1.0
D) 1.5

Question 25

The DRI Committee recommends _____ percent of total calories as the minimum amount of protein.

A) 5
B) 10
C) 15
D) 20

Question 26

If amino acids are oversupplied:

A) the body stores them until they are needed.
B) the body removes and excretes their amine groups.
C) the body converts amino acid residues to glycogen or fat.
D) a and b
E) b and c

Question 27

The DRI for protein depends on:

A) height.
B) activity level.
C) body size.
D) sex.

Question 28

For athletes, the path to bigger muscles includes

A) vigorous physical training.
B) well-timed meals.
C) excess protein consumption.
D) a and b
E) b and c

Question 29

Amino acids are "wasted" (not used to build protein or nitrogen-containing compounds) in the body whenever there is:

A) not enough energy from carbohydrate and fat.
B) too much protein.
C) adequate high-quality protein.
D) a and b
E) b and c

Question 30

When amino acids are absorbed by the cells of the small intestine:

A) they are absorbed best in large doses of a single amino acid.
B) they are absorbed without preference at all sites on the cells.
C) they must be broken into single amino acids before they can be absorbed.
D) they can be circulated in the bloodstream to other cells and linked together to create new proteins.

Question 31

When amino acids are degraded for energy, their amine groups are stripped off and used elsewhere or incorporated by the liver into:

A) bile.
B) urea.
C) glucose.
D) urine.

Question 32

The role of enzymes in the small intestine in protein digestion is to split proteins into all except:

A) oligopeptides.
B) amino acids.
C) dipeptides.
D) tripeptides.

Question 33

All of the following cause denaturation of proteins except:

A) bases.
B) alcohol.
C) heat.
D) light.
E) salts of heavy metals.

Question 34

How many amino acids are considered to be essential amino acids?

A) 5
B) 7
C) 9
D) 13

Question 35

The process of protein turnover includes:

A) eating food sources of amino acids every day to grow new cells and replace worn-out ones.
B) synthesizing intestinal cells, which can live for months.
C) preserving all old amino acids in the body to be re-circulated.
D) excreting old amino acids that are left from cell breakdown.

Question 36

Negative nitrogen balance occurs in:

A) a surgery patient.
B) growing children.
C) pregnant women.
D) lactating women.

Question 37

The stomach lining is protected from the very strong acid of the stomach by:

A) enzymes.
B) a coat of mucus.
C) saliva.
D) antibodies.

Question 38

In making recommendations for protein intake, the committee on DRI took into consideration that the protein in a normal diet would be:

A) primarily from animal sources.
B) primarily from plant sources.
C) a combination of animal and plant sources.
D) used with 100% efficiency by everyone.

Question 39

All of the following are needed for the body to synthesize protein except:

A) adequate carbohydrate and fat.
B) an adequate total amount of protein.
C) all essential amino acids in the proper amounts.
D) amino acid supplements.

Question 40

A(n) _____ bond is formed between the amine group end of one amino acid and the acid group end of the next amino acid in a protein.

A) peptide
B) amino acid
C) denatured
D) sulfur

Question 41

The strategy of combining two _____ plant protein sources permits the amino acids in one food to make up for those lacking in the other food.

A) complementary
B) complete
C) high-tryptophan
D) a and b
E) b and c

Question 42

Of the following foods, which likely contains the most easily digestible protein?

A) oats
B) whole wheat
C) potatoes
D) tuna

Question 43

Is it a good idea to avoid acidic foods like tomatoes and orange juice in order to prevent acid stomach?

A) yes, because highly acidic foods increase the acidity of the stomach
B) no, because no food is acidic enough to make the stomach acid stronger
C) no, because the stomach is supposed to be acidic to do its job
D) a and b
E) b and c

Question 44

The genetic coding or expression that determines our DNA messaging for cells is:

A) identical in all people to ensure that cells are developed properly.
B) available in all cells but is idle in some cells and active in others.
C) not influenced by any changes in nutrient intake.
D) easily changed if a disease develops in the body.

Question 45

An overemphasis on protein-rich foods can lead to:

A) a low intake of iron.
B) a low intake of folate.
C) a low intake of vitamin C.
D) a and b
E) b and c

Question 46

The heavy use of soy products in place of meat can inhibit _____ absorption.

A) calcium
B) folate
C) iron
D) vitamin C
Application-Level Multiple-Choice Items

Question 47

Tim, who lost a large amount of weight during an illness, is thinking about taking amino acid supplements to help him regain muscle mass. What advice would you give him?

A) Amino acid supplements are an excellent way to quickly provide energy to muscles for rebuilding.
B) Taking amino acid supplements helps keep the digestive system from overworking while you recover from illness.
C) Extra carbohydrate, but never extra protein, is needed for recovery.
D) Whole protein is better handled by the digestive system and will better promote recovery.

Question 48

What is the result of a dietary protein deficiency?

A) increased synthesis of proteins
B) decreased breakdown of body protein
C) a weakened immune system
D) enhanced nutrient absorption

Question 49

Which of the following food groups does not provide significant protein?

A) fruits
B) grains
C) vegetables
D) milk, yogurt, and cheese

Question 50

Why should eggs be cooked, rather than eaten raw?

A) Raw egg proteins bind the mineral iron.
B) Raw egg proteins speed up protein digestion.
C) Raw egg proteins bind the B vitamin biotin.
D) b and c
E) a and c

Question 51

Which of the following is not associated with an excess of protein?

A) enlarged livers in humans
B) enlarged kidneys in animals
C) worsening of existing kidney problems
D) high-fat foods that contribute to obesity

Question 52

The more animal protein you eat, the higher your intake of _____.

A) vitamin B₁₂
B) vitamin A
C) folate
D) vitamin C

Question 53

Which of the following food categories contributes an abundance of high-quality protein?

A) vegetable
B) milk
C) meat
D) a and b
E) b and c

Question 54

Which of the following provides amino acids that are best absorbed by the body?

A) legumes
B) animal proteins
C) grains
D) vegetables

Question 55

The recycling system for amino acids in the body is primarily used to:

A) provide fuel for the cells to spare glucose.
B) convert nonessential amino acids into essential amino acids.
C) provide the cells with materials to build body proteins.
D) add protein to muscles when there is a shortage of energy from foods.

Question 56

Humans need to eat protein-containing foods regularly because:

A) we need essential amino acids that can only be provided by foods.
B) our bodies cannot make any amino acids needed for proteins.
C) the function of protein is to maintain our muscle strength.
D) protein is broken down quickly during digestion and lost from the body.

Question 57

Which of the following cooking methods would you use to increase the digestibility of protein?

A) frying
B) stewing
C) grilling
D) baking

Question 58

Which statement about the role of protein in a weight-loss plan is accurate?

A) Protein should contribute 65 percent or more of the calories.
B) There is no evidence that protein helps control the appetite.
C) It is the proper proportion of nutrients that brings about long-term weight loss.
D) Meeting protein recommendations during weight loss is critical for preserving lean tissues.

Question 59

Removing the grain protein gluten from the diet has been shown to:

A) resolve digestive problems in people with celiac disease.
B) help with weight loss in people trying to lose weight.
C) reduce problems with insomnia.
D) reduce cancer risk.

Question 60

Why is milk used as a first-aid remedy for someone who has swallowed a heavy-metal poison?

A) The poison acts on the protein in the milk rather than on the protein of the gastrointestinal tract.
B) Milk will cause the person to vomit and expel the poison.
C) Milk will provide calcium, which serves to render the poison harmless.
D) a and b
E) b and c

Question 61

A child suffering from protein deficiency develops edema. This is an example of protein's role in:

A) supporting growth and maintenance.
B) building enzymes and hormones.
C) maintaining fluid and electrolyte balance.
D) maintaining acid-base balance.

Question 62

In times of energy shortage from carbohydrates or fats in foods, the body uses protein in what way?

A) decreases the breakdown of food proteins for energy and uses stored glycogen
B) stores amino acids in the cells to be used later for energy
C) removes the nitrogen portion and burns the remaining fragments for energy
D) converts it to fat to provide more concentrated energy

Question 63

Proteins use the process of active transport to move substances in or out of the cell by:

A) opening passages in the membrane and escorting substances into the cell.
B) attaching to minerals to carry them throughout the bloodstream.
C) decreasing the water content in cells to get rid of excess acid or base levels.
D) sending antibodies to cells to carry excess proteins out to where they are needed.

Question 64

Cells will do all of the following to create their own working proteins from available amino acids except:

A) synthesize nonessential amino acids that are missing for the protein that is being made.
B) obtain amino acids that are available in the cell's amino acid pool.
C) slow down protein synthesis until enough of the limiting amino acid is available again.
D) hold partially completed proteins until the diet provides the missing amino acids.

Question 65

What is the DRI for protein for a 40-year-old male who is 6'4" tall and weighs 180 pounds?

A) 34 grams
B) 49 grams
C) 65 grams
D) 144 grams

Question 66

Examples of complementary protein combinations include all of the following except:

A) pasta with tomato sauce.
B) rice and black-eyed peas.
C) whole-wheat cereal with almonds.
D) peanut butter and jelly on whole-wheat bread.

Question 67

When you do not eat enough protein:

A) you may still be able to get an adequate nutrient intake.
B) you will develop symptoms of malnutrition.
C) your body will increase its synthesis of proteins.
D) your kidneys and liver will enlarge.

Question 68

The roles of enzymes formed by body proteins are important when foods are eaten because:

A) each enzyme is responsible for numerous different chemical reactions.
B) an enzyme acts as a catalyst to speed up a reaction without being altered itself.
C) enzymes signal certain organs to respond to a change in conditions in the body.
D) some enzymes can become chemical messengers in the nervous system.

Question 69

An adolescent girl has decided to adhere to a vegetarian diet and has selected a tossed green salad, whole-wheat crackers, and apple juice for lunch. What would you advise her about her complementary protein sources?

A) She has made good choices of complementary protein foods.
B) Adding garbanzo beans to her salad would provide the protein combination she needs.
C) She has to include milk or cheese with her meal or there will not be enough protein.
D) She should not be following a vegetarian diet because it is not nutritionally adequate.

Question 70

A sedentary male college student aged 23 needs how much protein if he weighs 175 pounds?

A) 46 grams/day
B) 64 grams/day
C) 86 grams/day
D) 140 grams/day

Question 71

Which of the following would have the highest protein DRI per unit of body weight?

A) a 28-year-old pregnant woman
B) a 6-year-old child
C) a 40-year-old male
D) a 34-year-old woman

Question 72

Certain proteins act as buffers in the blood. In this role they are responsible for:

A) providing immunity from foreign substances that invade the body.
B) making sure that sodium is transported outside the cells.
C) ensuring that too much fluid in the cells doesn't cause edema.
D) picking up and releasing hydrogens in the blood to balance its pH.

Question 73

Which of the following statements is true?

A) Athletes need slightly more protein than other healthy adults.
B) Athletes should consume protein supplements to build muscle.
C) Dieters should take protein supplements to spare body protein.
D) a and b
E) b and c

Question 74

What is one of the risks of consuming a diet high in protein?

A) significant loss of calcium from the body in urine
B) development of kidney disease
C) increased risk of heart disease with high intakes of fatty meats and whole milk
D) increased risk of heart disease with high intakes of legumes and nuts

Question 75

When comparing the digestion and absorption of proteins with fats it is important to know that:

A) proteins are broken down into individual amino acids and absorbed by all intestinal cells at an equal rate.
B) larger peptide molecules must be completely broken down into amino acids to be absorbed into the bloodstream from the intestine.
C) cells in the small intestine preferentially absorb different types of amino acids, which causes competition by amino acids at the absorption sites.
D) amino acids need a carrier in the bloodstream because they do not transport very well alone.

Question 76

An athlete consumes large amounts of meat in an effort to build extra muscle tissue. This practice does not work because:

A) the body has no place to store extra amino acids.
B) the body will dismantle its tissue proteins in this situation.
C) the body converts amino acid residues to fuel or stores them as fat.
D) a and b
E) a and c

Question 77

A young man has said to you that he is eating much more protein in his diet than the recommendation but he feels he needs the extra amount just in case he wants to build more muscle mass in the near future. How would you respond to him?

A) It should be fine because the cells will store the extra amino acids for future use.
B) If he has excess calories in his diet, he may gain fat weight from converted protein.
C) The extra protein will be used for fuel instead of the carbohydrate.
D) The body won't digest the extra protein and it will be eliminated in feces.

Question 78

A 10-year-old boy is going through a growth spurt. Because he needs to build new muscle tissue, what should his nitrogen status be?

A) positive nitrogen balance
B) negative nitrogen balance
C) nitrogen equilibrium
D) nitrogen deficiency

Question 79

The process of protein turnover involves:

A) the conversion of protein to glucose for energy in half of the protein we eat.
B) the loss of amino acids by excretion through the kidneys when cells die.
C) the use of amino acids that have been conserved from breakdown of old cells.
D) the annual replacement of old cells with new protein that has entered the body in food.

Question 80

A 135-pound woman needs how much protein?

A) 49 grams/day
B) 56 grams/day
C) 86 grams/day
D) 110 grams/day