Deck 19: Amino Acids and Proteins

Question 1

Collagen, a protein found in tendons and cartilage, would be classified as a ________ protein.

A)catalytic
B)structural
C)hormone
D)transport
E)storage

Answer 1

structural

Question 2

Give the correct name and three and one letter abbreviation for the amino acid shown.

A) Tyrosine, Tyr, T
B) Tryptophan, Trp, T
C) Tryptophan, Trp, W
D) Phenylalanine, Phe, P
E) Phenylalanine, Phe, F

Answer 2

Phenylalanine, Phe, F

Question 3

In a typical amino acid at physiological pH, the carboxylate is

A)positively charged.
B)attached to an amine.
C)negatively charged.
D)soluble in a nonpolar solvent.
E)neutral.

Answer 3

negatively charged.

Question 4

Which of the following would be most likely to be deficient in at least one essential amino acid?

A)milk
B)eggs
C)steak
D)beans
E)ham

Question 5

Amino acids that are not synthesized in the body and must be obtained from the diet are called

A)complete.
B)polar.
C)nonpolar.
D)incomplete.
E)essential.

Question 6

A basic amino acid has an R group that contains

A)a methyl group.
B)an amine group.
C)a carboxyl group.
D)a thiol group.
E)an alcohol group.

Question 7

Sucrase, the protein that facilitates the hydrolysis of sucrose, would be classified as a(n)________ protein.

A)structural
B)enzymatic
C)transport
D)contractile
E)hormonal

Question 8

The structural formulas of amino acids are the same EXCEPT for the

A)alpha carbon.
B)hydrogen bonding.
C)carboxyl group.
D)side chain or R group.
E)amino group.

Question 9

The peptide bonds that combine amino acids in the primary structure of a protein are

A)glycosidic bonds.
B)ether bonds.
C)ester bonds.
D)sulfide bonds.
E)amide bonds.

Question 10

The side chain for histidine is classified as a(n)________ R group.

A)polar
B)nonpolar
C)neutral
D)acidic
E)basic

Question 11

Which of the following is the correct structure for Ser-Ala-Asp? The R groups are

A)
B)
C)
D)
E)

Question 12

In the peptide Ala-Try-Gly-Phe, the N-terminal amino acid is

A)phenylalanine.
B)alanine.
C)tryptophan.
D)glycine.
E)aspartic acid.

Question 13

Methionine is an amino acid that contains

A)a sodium atom.
B)a sulfur atom.
C)a chlorine atom.
D)a heterocyclic ring.
E)a phenyl ring.

Question 14

Wool is primarily made up of

A)carbohydrate.
B)enkephalin.
C)triacylglycerols.
D)globin.
E)protein.

Question 15

Which of the following functional groups of an amino acid would be in the ionized state at high pH?

A)
B)
C)
D)
E)

Question 16

A completely vegetarian diet will contain all the essential amino acids if it includes

A)corn and beans.
B)almonds and walnuts.
C)wheat and corn.
D)wheat and rice.
E)rice and beans.

Question 17

Give the correct name and three and one letter abbreviation for the amino acid shown.

A) Valine, Vle, V
B) Alanine, Ala, A
C) Valine, Val, V
D) Isoleucine, Iso, I
E) Leucine, Leu, L

Question 18

Which of the following is NOT a function of proteins?

A)movement of muscles
B)catalyze reactions in the cells
C)provide structural components
D)store the genetic information of a living organism
E)transport substances through the bloodstream

Question 19

The following amino acid R group is

A)acidic.
B)basic.
C)hydrophilic.
D)hydrophobic.
E)polar.

Question 20

The R group for serine is In the ionized form, serine has the structural formula

A)

B)

C)

D)

E)

Question 21

Which of the following shows all of the tripeptides that can be formed from one molecule each of lysine (Lys), threonine (Thr), and histidine (His)?

A)Lys-Thr-His, Lys-His-Thr, His-Lys-Thr
B)Lys-Thr-His, Lys-His-Thr
C)Lys-Thr-His
D)Lys-Thr-His, Lys-His-Thr, His-Thr-Lys, His-Lys-Thr, Thr-Lys-His, Thr-His-Lys
E)Lys-Thr-His, Lys-His-Thr, His-Lys-Thr, Thr-His-Lys

Question 22

Which R group would most likely be found in a hydrophobic area of the tertiary structure of a protein?

A)
B)
C)
D)
E)

Question 23

Which of the following is an example of a secondary protein structure?

A)fatty acid
B)amino acid
C)dipeptide
D)a helix
E)triglyceride

Question 24

The fibrous protein responsible for the structure of hair and wool is

A)myosin.
B)endorphin.
C)keratin.
D)collagen.
E)casein.

Question 25

In the peptide Ser-Cys-Ala-Gly, the C-terminal end is

A)serotonin.
B)glycine.
C)serine.
D)alanine.
E)glycerine.

Question 26

The heme in hemoglobin

A) binds oxygen.
B) is a pleated sheet area in the hemoglobin molecule.
C) is a protein chain.
D) is a helix area in the hemoglobin molecule.
E) is an oxygen molecule within the hemoglobin molecule.

Question 27

Disulfide bonds in a protein chain connect

A)two asparagine residues.
B)an amine and a carboxylic acid group.
C)an alcohol and a carboxylic acid group.
D)tryptophan and alanine residues.
E)two cysteine residues.

Question 28

In insulin, two peptide chains are held together in a single unit by

A) a prosthetic group.
B)
C) disulfide bridges.
D) hydrogen bonds.
E) salt bridges.

Question 29

What type of interaction would you expect between the following R groups in the tertiary structure of a protein?

A)disulfide bonds
B)salt bridges
C)hydrogen bonds
D)hydrophobic interactions
E)peptide bonds

Question 30

Which of the following shows all of the tripeptides that can be formed from one molecule each of glycine (Gly), valine (Val), and leucine (Leu)?

A) Gly-Val-Leu
B) Val-Gly-Leu, Gly-Val-Leu, Gly-Leu-Val, Leu-Gly-Val
C) Gly-Val-Leu, Gly-Leu-Val, Val-Leu-Gly, Val-Gly-Leu, Leu-Gly-Val, Leu-Val-Gly
D) Val-Gly-Leu, Gly-Leu-Val
E) Gly-Val-Leu, Gly-Leu-Val, Leu-Gly-Val

Question 31

Which of the following is a secondary protein structure?

A)
B) disulfide bond
C) salt bridges
D) Ser-Met-Ala-Gly-Ile
E) hydrophobic interactions

Question 32

Within hemoglobin, the heme functions as

A) one of the four protein subunits.
B) an subunit.
C) an oxygen carrier.
D) a reducing agent.
E) a disulfide bridge.

Question 33

A chain made of more than 50 amino acids is usually referred to as a(n)

A)globulin.
B)peptide.
C)enzyme.
D)hormone.
E)protein.

Question 34

Hemoglobin is an example of a protein with

A) two protein chains held together.
B) primarily a
sheet structure.
C) primarily an structure.
D) primary structure only.
E) a quaternary structure.

Question 35

A peptide bond contains which kind of functional group?

A)carboxylic acid
B)alcohol
C)amine
D)amide
E)ketone

Question 36

The secondary structure of collagen is distinguished by

A) many helixes wound into fibrils.
B) a bundled triple helix.
C) many glycoside links.
D) single helix strands.
E) double helix strands.

Question 37

What type of interaction would you expect between the following R groups in the tertiary structure of a protein?

A)disulfide bonds
B)salt bridges
C)hydrogen bonds
D)hydrophobic interactions
E)peptide bonds

Question 38

The interactions that are important in the secondary structure of a protein are

A)disulfide bonds.
B)hydrogen bonds.
C)salt bridges.
D)peptide bonds.
E)hydrophobic interactions.

Question 39

Hemoglobin has a total of ________ protein chain(s)in its quaternary structure.

A)one
B)two
C)three
D)four
E)five

Question 40

What type of interaction would you expect between the following R groups in the tertiary structure of a protein?

A)disulfide bonds
B)salt bridges
C)hydrogen bonds
D)hydrophobic interactions
E)peptide bonds

Question 41

In sickle-cell anemia, the hemoglobin molecules

A)undergo crenation.
B)clump together into insoluble fibers.
C)enlarge to twice normal size.
D)come apart into separate chains.
E)dissolve in the plasma.

Question 42

Collagen can be classified as a ________ protein.

Question 43

One heavy metal that can cause denaturation of a protein is

A)silver.
B)barium.
C)calcium.
D)iron.
E)sodium.

Question 44

Denaturation of a protein

A)is always irreversible.
B)disrupts the secondary, tertiary, or quaternary structure of a protein.
C)changes the primary structure of a protein.
D)can only occur in a protein with quaternary structure.
E)hydrolyzes peptide bonds.

Question 45

In an enzyme, the polypeptide chain folds into a compact shape known as the ________ structure.

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

Question 46

Hydrophobic interactions help to stabilize the ________ structure(s)of a protein.

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

Question 47

An acid can denature a protein by

A)agitating the protein chains.
B)removing helping molecules such as heme.
C)disrupting hydrogen bonds between protein chains.
D)disrupting hydrophobic interactions within a protein chain.
E)breaking disulfide bridges.

Question 48

What type of amino acids have polar R groups that can be attracted to water?

A)aromatic
B)hydrocarbon
C)nonpolar
D)hydrophilic
E)hydrophobic

Question 49

Which of the following is characterized by three polypeptide chains.

A)
B) amyloids
C) collagen
D)

Question 50

In digestion, proteins are broken down into amino acids in a(n)________ reaction.

A)hydrolysis
B)saponification
C)reduction
D)oxidation
E)denaturation

Question 51

When two protein chains combine to form an active protein, the structural level is ________.

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

Question 52

What process occurs when heat, acids, bases, and heavy metal ions cause a loss of biological function of a protein?

A)denaturation
B)saponification
C)amidation
D)esterification
E)hydrogenation

Question 53

Heat denatures a protein by disrupting

A)ionic bonds and peptide bonds.
B)hydrogen bonds and disulfide bonds.
C)hydrophobic bonds and hydrogen bonds.
D)disulfide bonds and peptide bonds.
E)peptide bonds and hydrophobic bonds.

Question 54

What kinds of interactions are NOT part of tertiary protein structure?

A)peptide bonds
B)salt bridges
C)hydrophobic interactions
D)hydrophilic interactions
E)disulfide bonds

Question 55

What type of interaction occurs between the R groups of two serines?

A)salt bridge
B)hydrophilic
C)disulfide bond
D)hydrophobic
E)hydrogen bond

Question 56

Immunoglobulin, a protein that stimulates immune responses, would be classified as a ________ protein.

A)protection
B)catalytic
C)storage
D)transport
E)structural

Question 57

Acids and bases denature a protein by disrupting

A)hydrophobic interactions and peptide bonds.
B)salt bridges and hydrogen bonds.
C)amide bonds and alkene bonds.
D)peptide bonds and ionic bonds.
E)salt bridges and hydrophobic interactions.

Question 58

Heavy metals denature proteins by

A)releasing amino acids.
B)changing the pH of the protein solution.
C)disrupting disulfide bonds.
D)disrupting hydrophobic interactions.
E)changing the temperature of the protein solution.

Question 59

Which of the following combinations of food would supply all the essential amino acids?

A)corn and oats
B)corn and wheat
C)beans and almonds
D)beans and soy
E)oats and peas

Question 60

Consider the R groups of the following amino acids:
cysteine:
alanine:
serine:
The name for the dipeptide shown below is

A)seryl-alanine
B)serine-alanine
C)alanyl-serine
D)seryl-cysteine
E)alanyl-cysteine

Question 61

Circle the peptide bond in this structure.

Question 62

Proteins that stimulate immune response are known as ________.

Question 63

Write the structure of glycine at physiological pH.

Question 64

Amino acids that are not synthesized in the body but must be ingested with the diet are called ________ amino
acids.

Question 65

The ionized form of nearly all amino acids at physiological pH has a net charge of ________.

Question 66

The protein that transports oxygen in the blood is ________.