Question : 31.Which of the following types of interactions contribute to protein : 1309692

 

 

31.Which of the following types of interactions contribute to protein tertiary structure?

a.hydrophobic interactions between nonpolar R groups

b.hydrogen bonds between polar neutral R groups

c.hydrogen bonds between C=O and N–H groups

d.more than one correct response

e.no correct response

 

 

 

32.R-group interaction between which of the following pairs of amino acids produces a disulfide bond?

a.cysteine-cysteine

b.proline-proline

c.alanine-glycine

d.more than one correct response

e.no correct response

 

 

 

33.Which of the following levels of protein structure is not disrupted when protein hydrolysis occurs?

a.primary structure

b.secondary structure

c.tertiary structure

d.more than one correct response

e.no correct response

 

 

 

34.In which of the following pairs of proteins are both members of the pair fibrous proteins?

a.alpha-keratin and collagen

b.collagen and hemoglobin

c.hemoglobin and myoglobin

d.more than one correct response

e.no correct response

 

 

 

35.Which of the following statements concerning proteins is correct?

a.Some, but not all, multimeric proteins are also conjugated proteins.

b.All monomeric proteins are also simple proteins.

c.Some, but not all, globular proteins are also multimeric proteins.

d.More than one correct response.

e.No correct response.

 

 

 

Use the following to answer the questions below:

 

In each of the following multiple-choice questions, characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices:

a) All three statements are true.

b) Two of the three statements are true.

c) Only one of the statements is true.

d) None of the statements is true.

 

36.Statements:

(1) In pure form, amino acids are white crystalline solids with limited solubility in water.

(2) In an alpha-helix structure, all of the amino acid side chains lie outside the helix.

(3) Protein denaturation affects all four levels of protein structure.

a.All three statements are true.

b.Two of the three statements are true.

c.Only one of the statements is true.

d.None of the statements is true.

 

 

 

37.Statements:

(1) Some tertiary-structure interactions involve covalent bonding.

(2) Nonpolar amino acids contain one amino group, one carboxyl group, and a nonpolar side chain.

(3) The two amino acids present in a dipeptide are linked via an amide linkage.

a.All three statements are true.

b.Two of the three statements are true.

c.Only one of the statements is true.

d.None of the statements is true.

 

 

 

38.Statements:

(1) The major force responsible for protein secondary structure is hydrogen bonding.

(2) Amino acids found in proteins are almost always L-isomers.

(3) Conjugated proteins always contain one or more prosthetic groups.

a.All three statements are true.

b.Two of the three statements are true.

c.Only one of the statements is true.

d.None of the statements is true.

 

 

 

39.Statements:

(1) Partial hydrolysis of the tripeptide Ala-Gly-Cys produces three different dipeptides.

(2) The number of standard amino acids is 23.

(3) Enkephalins are peptides that bind at receptor sites in the brain to reduce pain.

a.All three statements are true.

b.Two of the three statements are true.

c.Only one of the statements is true.

d.None of the statements is true.

 

 

 

40.Statements:

(1) In a peptide, the number of amino acids and the number of peptide bonds are always equal.

(2) HDL and LDL are examples of lipoproteins.

(3) Tertiary structure interactions in proteins always involve amino acid R groups.

a.All three statements are true.

b.Two of the three statements are true.

c.Only one of the statements is true.

d.None of the statements is true.

 

 

 

41.Statements:

(1) In the tripeptide Gly-Ala-Ser, the amino acid at the N-terminal end is Ser.

(2) More than one polypeptide chain may be present in a conjugated protein but not in a simple protein.

(3) In solution at physiological pH, the side chain of a polar basic amino acid bears a negative charge.

a.All three statements are true.

b.Two of the three statements are true.

c.Only one of the statements is true.

d.None of the statements is true.

 

 

 

42.Statements:

(1) Collagen, the most abundant protein in humans, is both a fibrous protein and a glycoprotein.

(2) Quaternary structure, the highest level of protein organization, is found in all proteins in which 80 or more amino acids are present.

(3) A protein chain lacks directionality because its two ends always involve the same amino acid.

 

a.All three statements are true.

b.Two of the three statements are true.

c.Only one of the statements is true.

d.None of the statements is true.

 

 

 

43.Statements:

(1) For a tripeptide in which the three amino acids are different, six isomeric forms are possible.

(2) The “backbone” of a protein is an alternating sequence of C and N atoms.

(3) Both alpha-helix and beta-pleated sheet configurations can be present in the same protein.

a.All three statements are true.

b.Two of the three statements are true.

c.Only one of the statements is true.

d.None of the statements is true.

 

 

 

44.Statements:

(1) For neutral amino acids, three different forms can exist, with the form found dependent of solution pH.

(2) Hydrophobic interactions are the strongest of the tertiary-structure interactions.

(3) Protein digestion is an enzyme-catalyzed hydrolysis reaction.

a.All three statements are true.

b.Two of the three statements are true.

c.Only one of the statements is true.

d.None of the statements is true.

 

 

 

45.Statements:

(1) The antirejection drug cyclosporine is structurally a small cyclic peptide.

(2) The chemical basis for a hair permanent is reversible denaturation in which peptide linkages are broken and reformed.

(3) Immature human milk (colostrum) does not contain protein.

a.All three statements are true.

b.Two of the three statements are true.

c.Only one of the statements is true.

d.None of the statements is true.