Deck 6: Protein: Amino Acids

Question 1

Which of the follow is true of amino acid supplements?

A) They are whole proteins.
B) They keep the digestive system from overworking.
C) The digestive system handles whole proteins better than supplements.
D) They save the body from having to digest proteins.
E) They are rapidly excreted through the digestive system.

Answer 1

C

Question 2

Which of the following is a nonessential amino acid?

A) serine
B) histidine
C) valine
D) tryptophan
E) phenylalanine

Answer 2

A

Question 3

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

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

Answer 3

C

Question 4

Which term refers to the change in a protein's shape due to the application of heat or acid?

A) oxygenation
B) condensation
C) denaturation
D) destabilization
E) hydrolyzation

Question 5

Human insulin consists of 51 amino acids chemically bonded together, which classifies it a(an) ________.

A) unipeptide
B) dipeptide
C) tripeptide
D) oligopeptide
E) polypeptide

Question 6

In what part of the GI tract is pepsin active?

A) mouth
B) stomach
C) pancreas
D) small intestine
E) liver

Question 7

What percentage of dietary protein is hydrolyzed in the mouth?

A) 0
B) 5 to 10
C) 15 to 20
D) 25 to 30
E) 70 to 75

Question 8

What component  denatures protein structures and activates pepsinogen?

A) hydrochloric acid
B) pepsin
C) trypsin
D) enteropeptidase
E) chymotrypsin

Question 9

Which of the following is the primary factor that differentiates one amino acid from another?

A) the side group
B) the central carbon atom
C) the amino group
D) the acid group
E) the presence of a central hydrogen atom

Question 10

Digestive enzymes are ________ and function optimally at their specific pH.

A) lipids
B) carbohydrates
C) sterols
D) proteins
E) supplements

Question 11

What happens when pepsin enters the small intestine?

A) It activates HCl.
B) It is digested due to the high pH.
C) It cleaves proteins into smaller peptides and some free amino acids.
D) It inhibits pepsinogen synthesis.
E) It denatures protein structures.

Question 12

Amino means containing ________.

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

Question 13

What is the simplest amino acid?

A) phenylalanine
B) glycine
C) glutamine
D) lysine
E) tryptophan

Question 14

Which of the following is an essential amino acid?

A) cysteine
B) valine
C) glutamine
D) glycine
E) aspartic acid

Question 15

Which digestive enzyme hydrolyzes protein in the stomach? chymotrypsin

A) elastase
B) pepsin
C) trypsin
D) enteropeptidase
E) chymotrypsin

Question 16

Which of the following terms describes an amino acid that is normally dispensable, but must be supplied by the diet in special circumstances when the need for it exceeds the body's ability to make it?

A) conditionally nonessential amino acid
B) conditionally essential amino acid
C) nonessential amino acid
D) essential amino acid
E) circumspect amino acid

Question 17

Of all the amino acids, how many must be supplied by the diet?

A) 2
B) 5
C) 9
D) 13
E) 17

Question 18

What type of chemical reaction connects amino acids?

A) hydrolysis
B) oxidation
C) denaturation
D) condensation
E) polymerization

Question 19

The tangled shape of a polypeptide is its ________ structure, which gives it maximum stability.

A) primary
B) secondary
C) tertiary
D) quaternary
E) denaturalized

Question 20

What is the chief function of pepsin?

A) emulsifying dietary proteins
B) activating hydrochloric acid
C) activating pancreatic proteases
D) cleaving proteins into smaller polypeptides
E) emulsifying dietary fats

Question 21

Transamination produces a new nonessential amino acid and a new ________.

A) uric acid
B) keto acid
C) folic acid
D) gluco acid
E) phyto acid

Question 22

What is fibrin?

A) an antigen
B) an antibody
C) a light-sensitive protein
D) a blood clotting protein
E) a sterol

Question 23

The process whereby messenger RNA directs the sequence of amino acids and synthesis of proteins is ________.

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

Question 24

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) fatty acid

Question 25

Scars are made from which type of protein?

A) ferritin
B) albumin
C) collagen
D) hemoglobin
E) enzyme

Question 26

If a nonessential amino acid is not available, cells can make it from a keto acid if a(an)________ source is available.

A) carbonyl
B) nitrogen
C) ammonia
D) carbon
E) oxygen

Question 27

For whom is nitrogen balance typically positive?

A) pregnant women
B) starving children
C) burn victims
D) febrile children
E) adult men

Question 28

To build a bone or tooth, cells first lay down a ________ and then fill it with crystals of calcium, phosphorus, magnesium, fluoride, and other minerals.

A) matrix
B) enzyme grid
C) buffer
D) fluid regulator
E) transporter

Question 29

Proteins acts as buffers because they ________.

A) help emulsify fats
B) help maintain a constant pH
C) facilitate chemical reactions
D) help protect against plaque buildup
E) prevent degradation of proteins

Question 30

Which amino acid is used to synthesize the neurotransmitter epinephrine and the pigment melanin?

A) glycine
B) tyrosine
C) methionine
D) tryptophan
E) valine

Question 31

Which disease is caused by a sequencing error in the structure of hemoglobin, which changes its shape and characteristics?

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

Question 32

Which statement about protein transporters is FALSE?

A) Hemoglobin transports oxygen from the lungs to the cells.
B) Some transport proteins act as "pumps."
C) Iron is captured in an intestinal cell by a protein.
D) Transport proteins within a cell membrane pick up and release sodium and potassium across the membrane.
E) Active transport systems require no energy.

Question 33

The degradation and synthesis of protein is called "________."

A) protein turnover
B) nitrogen balance
C) amino acid pool
D) immunity
E) transamination

Question 34

How do proteins regulate fluid balance?

A) Proteins are hydrophilic.
B) Water attracts proteins.
C) Water degrades proteins.
D) Proteins form polymers of water.
E) Proteins are hydrophobic.

Question 35

What is a ribosome?

A) a template for protein synthesis
B) a protein transportation machine
C) a protein-making machine
D) an immune booster
E) a protein pool

Question 36

The process of messenger RNA being made from a template of DNA is ________.

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

Question 37

Viruses, bacteria, and toxins are examples of ________.

A) antigens
B) antibodies
C) buffers
D) acidosis
E) alkalosis

Question 38

Which of the following proteins inactivates foreign bacteria and viruses?

A) enzymes
B) collagen
C) hormones
D) antibodies
E) antigens

Question 39

Which protein, acting as a hormone, regulates blood glucose?

A) oxytocin
B) prolactin
C) thyroxine
D) antidiuretic
E) insulin

Question 40

When nitrogen losses exceed the amount of nitrogen taken into the body, the person is in ________.

A) a healthy state
B) nitrogen equilibrium
C) positive nitrogen balance
D) negative nitrogen balance
E) nitrogen homeostasis

Question 41

Which of the following is NOT a function of proteins in the body?

A) providing fuel for energy needs
B) facilitating chemical reactions
C) maintaining volume of body fluids
D) protecting the body against diseases
E) inhibiting the absorption of cholesterol

Question 42

A reference protein is determined by comparing its amino acid composition with the essential amino acid requirements of ________.

A) infants
B) preschool-age children
C) male teenagers
D) pregnant women
E) adult men

Question 43

Which statement accurately describes the relationship between dietary protein and kidney function?

A) Protein deficiency increases the risk of kidney stones.
B) Restricting dietary protein helps slow the progression of kidney disease.
C) Long-term, high-protein diets are a risk factor for kidney disease.
D) High urea production from high-protein diets increases kidney efficiency.
E) High-protein diets are recommended for childhood with genetic kidney issues.

Question 44

What is the average daily protein intake in United States?

A) 50 g
B) 65 g
C) 80 g
D) 125 g
E) 175 g

Question 45

Which of the following cannot support growth and health as a diet's sole protein?

A) fish
B) cheese
C) gelatin
D) turkey
E) fatty fish

Question 46

The production of urea hits its maximum rate at intakes approaching ________ grams of protein per day.

A) 5
B) 50
C) 100
D) 250
E) 500

Question 47

Which of the following foods contains all of the essential amino acids in relatively the same amounts that the human body requires?

A) turkey
B) quinoa
C) broccoli
D) gelatin
E) pumpkin seeds

Question 48

A vegetarian who plans a meal involving black beans can consume all the essential amino acids by adding another a plant protein rich in ________.

A) lysine
B) tyrosine
C) methionine
D) isoleucine
E) phenylalanine

Question 49

The digestibility of most animal proteins is ________.

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

Question 50

Which amino acid may protect against heart disease by lowering blood pressure and preventing blood clots?

A) arginine
B) cysteine
C) tryptophan
D) phenylalanine
E) methionine

Question 51

Which of the following is NOT an assumption made in the formulation of the RDA for protein?

A) People are healthy and do not have unusual metabolic needs for protein.
B) Dietary protein is of mixed quality.
C) Dietary carbohydrate and fat intakes are adequate.
D) The body will use protein efficiently.
E) Dietary protein needs are lower in infants and children.

Question 52

What is the most likely reason for a person to have abnormally high blood urea levels?

A) liver dysfunction
B) kidney dysfunction
C) rapid weight gain
D) protein intake one-tenth the RDA
E) hyperstimulation of the immune system

Question 53

An otherwise healthy person regularly consuming a high-protein diet risks ________.

A) liver disease
B) decreased size of the liver and kidneys
C) dehydration
D) ulcers
E) diabetes

Question 54

Which of the following are responsible for urea synthesis?

A) all amino acids
B) animal sources of proteins only
C) essential amino acids only
D) nonessential amino acids only
E) vegetarian sources of protein only

Question 55

The amino acid homocysteine is elevated in ________.

A) cancer
B) kidney disease
C) heart disease
D) protein-energy malnutrition
E) osteoporosis

Question 56

The protein RDA for adults is ________ grams per kilogram of body weight.

A) 0.08
B) 0.36
C) 0.8
D) 3.6
E) eight

Question 57

A vegetarian who plans a meal involving rice can consume all the essential amino acids by adding another plant protein rich in ________.

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

Question 58

The digestibility of most plant proteins (beside legumes) is ________.

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

Question 59

Which of the following is not a limiting amino acid?

A) lysine
B) methionine
C) threonine
D) tryptophan
E) serine

Question 60

Which of the following would NOT be classified as a carcinogen by the World Health Organization?

A) bacon
B) hot dogs
C) beef jerky
D) chicken
E) ham

Question 61

Which term refers to the study of how genes influence the activities of nutrients?

A) nutrigenetics
B) nutrigenomics
C) genetic synthesis
D) human nutritional economics
E) bioproteomics

Question 62

The swelling of body tissue caused by excessive amounts of fluid in the interstitial spaces is called "________."

Question 63

________ is the process by which a cell converts the genetic code into RNA and protein.

Question 64

A bond that connects the acid end of one amino acid with the amino end of another, forming a link in a protein chain, is called a "________."

Question 65

A measure of the amount of amino acids absorbed from a given protein take is called "________."

Question 66

A ________ provides a standard against which to measure the quality of other proteins.

Question 67

________ refers to the change in a protein's shape and consequent loss of its function brought about by heat, agitation, acid, base, alcohol, heavy metals, or other agents.

Question 68

Approximately  how many protein-coding genes are in the human genome?

A) 5000 to 7000
B) 10,000 to 15, 000
C) 20,000 to 25, 000
D) 40,000 to 45, 000
E) 80,000 to 85, 000

Question 69

The term meaning "a substance that can cause cancer" is ________.

Question 70

Which nutrient participates in demethylation?

A) folate
B) a phytochemical in green tea
C) lysine
D) vitamin C
E) iron

Question 71

Which amino acid has been advertised in the popular media for treating insomnia and depression?

A) glycine
B) arginine
C) tryptophan
D) phenylalanine
E) proline

Question 72

Which of the following statements about whey protein is FALSE?

A) It is popular among athletes hoping to build muscle.
B) It is found in many affordable protein powders.
C) It is a waste product of cheese production.
D) It benefits body tissues in ways dietary proteins cannot.
E) It has a high leucine content and is digested quickly.

Question 73

Amino acids that the body can make are called "________."

Question 74

The incidence of PKU in the United States affects 1 in every _____ people.

A) 15,000
B) 100,000
C) 500,000
D) 10,000
E) 1,000,000

Question 75

In epigenetics , methylation involves ________.

A) the addition of a methyl group
B) the removal of a methyl group
C) the failure to metabolize tyrosine
D) the removal of amino acids
E) the addition of glucose

Question 76

Which term refers to the study of how nutrients influence the activities of genes?

A) nutrigenetics
B) nutrigenomics
C) genetic synthesis
D) human nutritional economics
E) bioproteomics

Question 77

A diet that restricts phenylalanine and supplies tyrosine is the only current treatment for people born with the single-gene disorder ________.

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

Question 78

The essential amino acids leucine, isoleucine, and valine, which are present in large amounts in skeletal muscle tissue are called ________ amino acids.

Question 79

The inactive form of pepsin is called "________."

Question 80

About how much protein is provided by 1 cup of milk?

A) 4 g
B) 8 g
C) 16 g
D) 32 g
E) 56 g