Deck 6: Protein: Amino Acids

Question 1

What type of reaction is required to bind two molecules of glycine together and release a molecule of water?

A)Hydrolysis
B)Deamination
C)Denaturation
D)Condensation
E)Transnaturation

Answer 1

D

Question 2

The chief function of pepsin is to ____.

A)emulsify dietary proteins
B)activate hydrochloric acid
C)activate pancreatic proteases
D)cleave proteins into smaller polypeptides
E)renature nonessential proteins

Answer 2

D

Question 3

What 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
E)The presence of a central hydrogen atom

Answer 3

A

Question 4

The function of a protease is to ____.

A)hydrolyze proteins
B)synthesize proteins
C)hydrolyze ribosomes
D)synthesize ribosomes
E)synthesize macrophages

Question 5

What is the process by which heat or acidity disrupts the normal shape of a protein chain?

A)Digestion
B)Condensation
C)Denaturation
D)Hydrogenation
E)Hydrolysis

Question 6

Which element is found in certain amino acids?

A)Iron
B)Sulfur
C)Calcium
D)Potassium
E)Mercury

Question 7

Which item is contained in an amino acid?

A)An acid group
B)An ester group
C)An aldehyde group
D)A central hydrogen atom
E)A central oxygen atom

Question 8

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 four polypeptide chains.
D)It has no primary or secondary structure.
E)It is a ring protein.

Question 9

What digestive enzyme would be most affected in people who are unable to produce hydrochloric acid?

A)Pepsin
B)Transaminase
C)Pancreatic protease
D)Intestinal peptidase
E)Salivary protease

Question 10

What is the usual fate of orally ingested enzyme supplements?

A)Digestion by gastrointestinal proteases
B)Rapidly degradation by salivary secretions
C)Almost complete absorption in original form from the stomach
D)Complete absorption in original form from the jejunum
E)Rapid excretion through the digestive system

Question 11

An example of a protein with quaternary polypeptide structures is ____.

A)insulin
B)tryptophan
C)hemoglobin
D)disulfide bridges
E)valine

Question 12

In what organ is pepsin active?

A)Stomach
B)Pancreas
C)Small intestine
D)Large intestine
E)Liver

Question 13

Which item is a nonessential amino acid in human nutrition?

A)Proline
B)Threonine
C)Methionine
D)Tryptophan
E)Phenylalanine

Question 14

Which item is an essential amino acid?

A)Cysteine
B)Leucine
C)Glutamine
D)Serine
E)Alanine

Question 15

What amino acid is classified as conditionally essential when dietary intake of phenylalanine is insufficient or the body cannot normally metabolize phenylalanine?

A)Cysteine
B)Tyrosine
C)Glutamine
D)Isoleucine
E)Asparagine

Question 16

What is the simplest amino acid?

A)Valine
B)Glycine
C)Alanine
D)Methionine
E)Tryptophan

Question 17

When two amino acids are chemically joined together, the resulting structure is called a ____.

A)dipeptide
B)diglyceride
C)polypeptide
D)disaccharide
E)polysaccharide

Question 18

Which term is used to classify amino acids in the diet?

A)Essential
B)Unessential
C)Partially essential
D)Moderately essential
E)Rarely essential

Question 19

The application of heat or acid to a protein that causes its shape to change is known as ____.

A)stiffening
B)condensation
C)denaturation
D)destabilization
E)hydrolization

Question 20

What best describes the structure of pepsin?

A)Lipid
B)Protein
C)Nucleic acid
D)Carbohydrate
E)Sterol

Question 21

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
E)The product of failed protein synthesis

Question 22

What is the most likely side effect of a high-protein, low-carbohydrate diet?

A)Diarrhea
B)Increased thirst
C)Nitrogen toxicity
D)Increased water retention in the body
E)Weight gain

Question 23

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
E)nitrogen homeostasis

Question 24

How do sodium and potassium travel into and out of cells?

A)Antidiuretic hormone transports potassium and prodiuretic hormone carries sodium.
B)Specific transport proteins in the blood 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)Transport proteins within the cell membrane pick up and release the minerals across the membrane.
E)A negative feedback loop uses blood glucose levels for transfer.

Question 25

Which substance is involved in the clotting of blood?

A)Opsin
B)Fibrin
C)Collagen
D)Transferrin
E)Thyroxin

Question 26

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
E)phyto acid

Question 27

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
E)500 g

Question 28

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
E)The failure of the body to form needed proteins

Question 29

What function does a buffer perform?

A)It helps emulsify fats.
B)It helps maintain a constant pH.
C)It facilitates chemical reactions.
D)It helps protect against plaque buildup.
E)It prevents degradation of proteins.

Question 30

What is the usual state of nitrogen balance for healthy infants, children, and pregnant women?

A)Equilibrium
B)Metabolic
C)Positive
D)Negative
E)Homeostatic

Question 31

What amino acid is used to synthesize the neurotransmitter serotonin and the vitamin niacin?

A)Glycine
B)Tyrosine
C)Methionine
D)Tryptophan
E)Valine

Question 32

Which of the following may be used to determine protein utilization?

A)Calorimetry
B)Nitrogen balance
C)Amino acid pool
D)Supplementary value
E)Body mass index

Question 33

What is opsin?

A)An antigen
B)An antibody
C)A light-sensitive protein
D)A blood transport protein
E)A sterol

Question 34

The process whereby messenger RNA is made from a DNA template is ____.

A)expression
B)sequencing
C)transcription
D)ribosome assembly
E)translation

Question 35

A common genetic variation which causes a change in the amino acid sequence in the structure of hemoglobin leads to the disease ____.

A)diabetes
B)marasmus
C)phenylketonuria
D)sickle-cell anemia
E)hemolytic anemia

Question 36

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
E)The essential and nonessential amino acids from dietary intake that are available for protein synthesis

Question 37

What type of protein would the body make in order to heal a wound?

A)Ferritin
B)Albumin
C)Collagen
D)Hemoglobin
E)Enzyme

Question 38

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
E)consumes a very low fat diet

Question 39

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.
E)Proteins repel water.

Question 40

Which of the following describes the structure of an antibody?

A)Tripeptide
B)Small nucleic acid
C)Huge protein molecule
D)Large peptide molecule
E)Location of carbons

Question 41

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
E)An amino acid that has the paradoxical effect of causing catabolism

Question 42

What would be the primary principle of wise diet planning as related to protein nutrition?

A)Variety
B)Moderation
C)Nutrient density
D)kCalorie control
E)Balance

Question 43

Which animal-derived protein is classified as a poor-quality protein?

A)Fish
B)Cheese
C)Gelatin
D)Turkey
E)Fatty fish

Question 44

Which statement characterizes the 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.
E)A significant majority of vegetarians experience clinically significant protein malnutrition.

Question 45

Which of the following food proteins has the best assortment of essential amino acids for the human body?

A)Egg
B)Rice
C)Corn
D)Gelatin
E)Soy

Question 46

If the diet is lacking an essential amino acid, what will be the likely 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.
E)Massive muscle wasting will occur.

Question 47

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
E)Recycled in the liver

Question 48

Excessive amounts of homocysteine in the blood are thought to increase the risk for ____.

A)cancer
B)diabetes
C)heart disease
D)protein-energy malnutrition
E)hypothyroidism

Question 49

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
E)Hyperstimulation of the immune system

Question 50

What is the percent digestibility of most plant proteins?

A)30-50
B)50-60
C)60-70
D)70-90
E)90-99

Question 51

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
E)Hyperstimulation of the immune system

Question 52

In general, the protein quality in grains would be most improved by the addition of a plant protein rich in ____.

A)lysine
B)tryptophan
C)phenylalanine
D)glutamic acid
E)methionine

Question 53

Which amino acid has been reported to lower blood pressure and reduce homocysteine levels?

A)Arginine
B)Cysteine
C)Tryptophan
D)Phenylalanine
E)Methionine

Question 54

Which statement 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.
E)High protein diets in childhood protect the kidneys from age- and illness-associated damage.

Question 55

In general, the protein quality of legumes would be most improved by the addition of a plant protein rich in ____.

A)lysine
B)tyrosine
C)methionine
D)glutamic acid
E)phenylalanine

Question 56

What is the process whereby an amino group is combined with a keto acid to form an amino acid?

A)Deamination
B)Ureagenesis
C)Transamination
D)Ammoniogenesis
E)Ketoacidosis

Question 57

Which statement describe 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.
E)High blood levels of phenylalanine dampen inflammatory responses, reducing risk of heart disease.

Question 58

What 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
E)Improved renal functioning

Question 59

What is the percent digestibility of most animal proteins?

A)50-59
B)60-69
C)70-79
D)80-89
E)90-99

Question 60

What is the actual ratio of calcium to protein intake (mg to g) for most U.S. women?

A)3:1
B)9:1
C)13:1
D)21:1
E)36:1

Question 61

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.
E)Dietary protein needs are lower in infants and children.

Question 62

A variation in a single nucleotide of a DNA strand is called a(n) ____.

A)RNA switch
B)thymine substitution
C)environmental mutation
D)single nucleotide polymorphism
E)replication failure

Question 63

The study of how food interacts with genes is known as ____.

A)nutritional genomics
B)chromosomal nutrition
C)nucleotide expression
D)mutagenic expression
E)personalized nutrition

Question 64

The disease phenylketonuria is related chiefly to abnormal metabolism of ____.

A)lactose
B)omega-3 fats
C)soy polysaccharides
D)a specific amino acid
E)glucose

Question 65

____________________ is the process of messenger RNA directing the sequence of amino acids and synthesis of proteins.

Question 66

____________________ are composed of carbon, hydrogen, oxygen, and nitrogen atoms, arranged into amino acids linked in a chain.

Question 67

Which of the following is a feature of whey protein?

A)It is a high-priced protein supplement.
B)It is chemically extracted from gelatin.
C)It is a waste product of cheese production.
D)It enhances athletic performance when regularly consumed.
E)It is no longer legal to use in over-the-counter products

Question 68

What amino acid supplement has been advertised in the popular media for treating herpes infections?

A)Lysine
B)Arginine
C)Tryptophan
D)Phenylalanine
E)Methionine

Question 69

The area of study that examines how environmental factors influence gene expression without changing the DNA is known as ____.

A)genetics
B)genomics
C)nutritional genomics
D)epigenetics
E)nutrigenetics

Question 70

The term ____________________ is used to describe the condition that develops when the diet delivers too little protein, too little energy, or both.

Question 71

____________________ provide enough of all the essential amino acids needed to support the body's work.

Question 72

Breaking down reactions are called ____________________ and building up reactions are called ____________________.

Question 73

____________________ enzymes on the membrane surfaces of the intestinal cells split most of the dipeptides and tripeptides into single amino acids.

Question 74

What amino acid has been linked to the development of the rare blood disorder eosinophilia-myalgia syndrome in people who took it as a supplement?

A)Glycine
B)Arginine
C)Tryptophan
D)Phenylalanine
E)Proline

Question 75

The supply of amino acids derived from either food proteins or body proteins that collect in the cells and circulating blood and stand ready to be incorporated in proteins and other compounds or used for energy is called the ____________________.

Question 76

What is a feature of the protein RDA?

A)The recommendations are generous.
B)The recommendations are highest proportionately for adult males.
C)The recommendations are established at 8 grams per kilogram of ideal body weight.
D)The recommendations assume that dietary protein is from animal sources only.
E)The recommendations fail to consider the need to replace damaged tissues.

Question 77

The simplest amino acid, ____________________, has a hydrogen atom as its side group.

Question 78

____________________ is the process of messenger RNA being made from a template of DNA.

Question 79

The ____________________ is determined by weak electrical attractions within the polypeptide chain.

Question 80

Dietary restriction of phenylalanine combined with adequate tyrosine is the usual treatment for people born with the disorder ____.

A)DNA
B)ALC
C)NLM
D)PKU
E)BHA