Deck 5: Protein

Question 1

Protein-rich food sources include meats, fish, nuts, and beans.

Answer 1

True

Question 2

The three steps involved in the process of protein synthesis are cell signaling, transcription, and

A) transamination.
B) deamination.
C) translation.
D) peptide bond cleavage.

Answer 2

C

Question 3

Transcription is

A) the process by which messenger RNA is constructed using DNA as a template.
B) the process of messenger RNA carrying the DNA information out of the nucleus.
C) the process by which a gene is directly converted into a protein.
D) the process by which messenger RNA is directly converted into a protein.

Answer 3

A

Question 4

The process of transamination

A) is used to synthesize nonessential amino acids.
B) is the process of transferring an amino group from an α-keto acid to an essential amino acid.
C) is the process of transferring an amino group from a nonessential amino acid to an essential amino acid.
D) is the process of transferring an amino group from an essential amino acid to a nonessential amino acid.

Question 5

Chemical digestion of proteins begins in the mouth.

Question 6

The American College of Sports Medicine states that athletes require more dietary protein than non-athletes.

Question 7

Amino acids can be used for ATP production.

Question 8

The primary structure of a protein is

A) the final structure of the protein.
B) the linear arrangement of amino acids in a single peptide chain.
C) determined by cell signaling events.
D) altered during protein folding.

Question 9

At-risk groups for protein-energy malnutrition include people with cancer or severe burns and alcoholics.

Question 10

When dietary protein consumption exceeds protein needs, the extra amino acids can be converted to fat and stored.

Question 11

Nonessential amino acids

A) are not recycled by the body.
B) can be synthesized from other compounds in the body.
C) are used to synthesize nonessential proteins.
D) all have the same side-chain group.

Question 12

Essential amino acids are defined as

A) those that cannot be made by the body in the amounts required and therefore must be consumed in the diet.
B) those that are difficult to find in a well-balanced diet and must be consumed as supplements.
C) those whose nitrogen-containing amino groups must be added in the liver.
D) those required for the synthesis of a limited number of essential proteins.

Question 13

A gene is

A) a section of DNA that is only used in reproduction.
B) a section of DNA that contains the information necessary to produce a particular protein.
C) a section of DNA that is converted to transfer RNA.
D) a section of DNA that moves outside the nucleus when protein synthesis is required.

Question 14

Denaturation disrupts a protein's three-dimensional shape, and therefore causes the protein to lose its function.

Question 15

The human body can recycle and reuse most of its amino acids from disassembled proteins through protein turnover.

Question 16

Translation is the process

A) by which messenger RNA leaves the nucleus.
B) by which amino acids are joined using peptide bonds.
C) by which messenger RNA is constructed using DNA as a template.
D) of protein folding.

Question 17

Whole proteins can be absorbed through a healthy intestine.

Question 18

The three common components of all amino acids are: a central carbon atom bonded to a hydrogen atom, a carboxylic acid group, and

A) a common side-chain group.
B) a sulfur-containing amino group.
C) a nitrogen-containing amino group.
D) a positively charged R-group.

Question 19

Foods supplying low amounts of one or more essential amino acids are called

A) incomplete protein sources.
B) complementary protein sources.
C) limiting foods.
D) nonessential foods.

Question 20

A protein's shape depends on its amino acid sequence.

Question 21

Disruption of protein folding by mechanical shaking, heat, detergents, or acids is called

A) denaturation.
B) transamination.
C) translation.
D) refolding.

Question 22

When nitrogen intake exceeds loss the body is in

A) nitrogen balance.
B) negative nitrogen balance.
C) positive nitrogen balance.

Question 23

Deep Check
Because they do not consume any animal products, vegans must make extra efforts to include nutrients that are found in animal products but to a much lesser degree, if at all, in plant products. These nutrients are iron, calcium, zinc, and

A) vitamin B₁₂.
B) vitamin
C)
C) vitamin K.
D) vitamin

Question 24

The most common food allergies are caused by proteins present in eggs, milk, soy, wheat, and

A) peanuts.
B) walnuts.
C) brazil nuts.
D) coconuts.

Question 25

Kwashiorkor is a form of protein-energy malnutrition characterized by

A) extreme wasting of muscles.
B) gain of abdominal adipose tissue.
C) severe edema in the extremities.
D) unusual growth of the jaw.

Question 26

Protein turnover is

A) the coordinated and continual process of breaking down and resynthesizing proteins.
B) the 3-dimensional rotation of proteins within cells.
C) the breakdown of proteins with subsequent destruction of amino acids.
D) the continual synthesis of proteins following excretion of nonfunctional proteins.

Question 27

An example of protein complementation is

A) steak and salmon.
B) rice and beans.
C) corn and rice.
D) whole grain and refined rice.

Question 28

The role of bicarbonate released from the pancreas is to

A) neutralize the acid from the stomach.
B) convert pepsinogen to pepsin.
C) activate the proenzymes released from absorptive cells lining the small intestine.
D) act as a protease.

Question 29

Marasmus is a form of protein-energy malnutrition characterized by

A) extreme wasting of muscles.
B) gain of abdominal adipose tissue.
C) severe edema in the extremities.
D) unusual growth of the jaw.

Question 30

A person's _____ is found inside the cell. In contrast, a person's _____ is what is outwardly apparent to another person.

A) genotype, phenotype
B) phenotype, genotype
C) DNA, protein profile
D) genetic mutation, genotype

Question 31

The hormones released by cells in the small intestine in response to the arrival of amino acids and smaller peptides are secretin and cholecystokinin. Together, these hormones stimulate

A) the production of hydrochloric acid and pepsinogen in the stomach.
B) the release of active enzymes from the pancreas.
C) the release of bicarbonate and proenzymes from the pancreas.
D) the release of di- and tripeptides from the absorptive cells that line the small intestine.

Question 32

One of the first events that occurs in the stomach in response to the presence of food is the release of _____, a hormone that stimulates the stomach to produce gastric juices.

A) cholecystokinin
B) gastrin
C) secretin
D) insulin

Question 33

The World Cancer Research Fund and the American Institute for Cancer Research recommend that people limit their intake of red meat to no more than 18 ounces every week and eat very little processed meat. These recommendations are explained by

A) the association of chronic high consumption of red meat or processed meats with increased risk of colorectal cancer.
B) the association of chronic high consumption of red meat or processed meats with increased risk of breast cancer.
C) the association of chronic high consumption of red meat or processed meats with increased risk of obesity, a risk factor for certain cancers.
D) the association of chronic high consumption of red meat or processed meats with increased risk of lung cancer.

Question 34

Secretin, gastrin, insulin, and glucagon are examples of proteins that are

A) enzymes.
B) hormones.
C) antibodies.
D) neurotransmitters.

Question 35

HCl is important for protein digestion for two reasons: 1) it denatures proteins in the stomach, and 2)

A) it stimulates gastrin release from the stomach.
B) it converts pepsinogen into pepsin.
C) it converts pepsin into pepsinogen.
D) it maintains the acid environment necessary in the small intestine for protein digestion.

Question 36

Pepsinogen is an example of a proenzyme. This means it is

A) an inactive form an enzyme.
B) an enzyme needed for protein digestion.
C) a protease.
D) an enzyme that leads the way for a different enzyme to have activity.

Question 37

Animal-derived foods are considered to be more complete protein sources than plant-derived foods because

A) they contain all of the essential amino acids, while plant-derived foods contain no essential amino acids.
B) they contain all of the essential amino acids, while plant-derived foods contain low amounts of one or more of the essential amino acids.
C) they contain all 20 of the amino acids used for protein synthesis in the human body, while plant-derived foods contain only 11 amino acids.
D) they contain only essential amino acids, while plant-derived foods contain only nonessential amino acids.

Question 38

The problem of a limiting amino acid is most simply overcome by

A) combining foods with different limiting amino acids to complement each other and provide adequate amounts of all the essential amino acids.
B) combining foods with the same limiting amino acid to increase the amount of that amino acid to an adequate level.
C) increasing portion size of a food with a limiting amino acid so that more of that amino acid is consumed.
D) reducing portion size of complete proteins so that the amount of the limiting amino acid is relatively increased.

Question 39

The shape of all proteins ranging from small, simple proteins to large, complex proteins is determined by

A) charge interactions.
B) moving outside the cell.
C) their amino acid sequences.
D) the addition of prosthetic groups.

Question 40

When nitrogen loss exceeds intake the body is in

A) nitrogen balance.
B) negative nitrogen balance.
C) positive nitrogen balance.

Question 41

Amino acids are not excreted intact. Rather,

A) the nitrogen-containing amino group is recycled while the remainder of the molecule is excreted in the urine.
B) the nitrogen-containing amino group is removed and converted to urea, which is excreted in the urine.
C) the carboxylic acid group is removed, neutralized by the bile, and excreted in the feces.
D) the side-chain group is removed and excreted while the reminder of the molecule is recycled.

Question 42

A person's _____ is largely determined by their _____.

A) phenotype, genotype
B) genotype, phenotype
C) height, phenotype

Question 43

During times of starvation or illness a nitrogen balance study would likely demonstrate

A) nitrogen balance.
B) negative nitrogen balance.
C) positive nitrogen balance.

Question 44

The complete digestion of proteins in the small intestine yields

A) only single amino acids that are absorbed across the absorptive cells into the blood.
B) single amino acids and di- and tripeptides that are broken down to single amino acids by protesases in the absorptive cells.
C) α-keto acids and amino groups that are reassembled in the absorptive cells prior to entering the blood.

Question 45

Alterations that change the sequence of information in a gene, leading to a change in the primary structure of a protein, are called

A) epigenetic modifications.
B) epigenetic changes.
C) transcriptional modifications.
D) mutations.

Question 46

In a protein-deficient state one cannot make _____ to fight off infectious agents.

A) albumin
B) hormones
C) enzymes
D) antibodies

Question 47

During childhood or recovery from an illness, a nitrogen balance study would likely demonstrate

A) nitrogen balance.
B) negative nitrogen balance.
C) positive nitrogen balance.

Question 48

When _____ production is reduced because of protein deficiency, _____ can result from fluid imbalance.

A) albumin, edema
B) protein, infection
C) collagen, arthritis
D) collagen, edema

Question 49

The phenomenon that explains why identical twins may differ in certain ways is most appropriately called

A) a mutation.
B) epigenetic variation.
C) sequential variation.
D) transcriptional variation.

Question 50

Collagen is an example of

A) a structural protein.
B) a catalytic protein.
C) a hormone.
D) an immune protein.

Question 51

The RDA for protein is 0.8 g/kg/day. Todd is 5'10" and weighs 80 kg (about 175 pounds). According to the RDA, he requires

A) 6.4 grams of protein per day.
B) 64 grams of protein per day.
C) 640 grams of protein per day.
D) none of the above; this cannot be determined based on the information provided.

Question 52

Alterations that modify a gene by changing its regulation but not the sequence of information are called

A) mutations.
B) phenotypic changes.
C) transcriptional modifications.
D) epigenetic modifications.

Question 53

Nitrogen balance studies are used to assess

A) protein status.
B) urea production.
C) protein absorption.
D) protein excretion.

Question 54

Chemical digestion of protein begins in the stomach, where _____ denatures proteins and _____ begins to digest them into smaller pieces.

A) hydrochloric acid, pepsinogen
B) hydrochloric acid, pepsin
C) gastrin, hydrochloric acid
D) gastrin, pepsin

Question 55

The Acceptable Macronutrient Distribution Range (AMDR) for protein is 10 to 35% of total energy intake. If Hannah consumes 2,000 kcal/day, her range of protein intake should be

A) 5 to 18 g/day
B) 25 to 100 g/day
C) 50 to 175 g/day
D) 100 to 250 g/day