Question 1

At the interface between subunits of a protein with quaternary structure, which of the following interactions between amino acid side chains would contribute to the stability of the dimer?

Accepted Answer

A)   glutamate-aspartate.
B)   leucine-aspartate.
C)   glutamate-lysine.
D)   phenylalaninelysine.E) B) and C)
F) None of the above

Question 2

Which amino acid has the highest pKa?

Accepted Answer

A)   glutamate
B)   asparagine
C)   cysteine
D)   lysineE) B) and D)
F) B) and C)

Question 3

Use the table below and write out the amino acid sequence coded by the following RNA sequence: AUG_CAC_AGG_UGA.

Accepted Answer

The answer of Use the table below and write out...

Question 4

Which interaction largely stabilizes protein secondary (2 °\degree° )  structures?

Accepted Answer

A)   disulfide bonds
B)   hydrogen bonding
C)   hydrophobic packing
D)   metal ions E) B) and D)
F) C) and D)

Question 5

Which amino acid contains a hydroxyl group?

Accepted Answer

A)   valine
B)   cysteine
C)   threonine
D)   aspartateE) B) and C)
F) C) and D)

Question 6

It is important for cells to degrade misfolded proteins. If misfolded proteins are not degraded, the misfolded proteins may

Accepted Answer

A)   waste excessive ATP in attempts to refold them.
B)   aggregate and interfere with normal cellular function.
C)   eventually refold, but not until excessive and sometimes fatal levels of cellular energy are spent.
D)   be excreted from the cell rather than recycled for building blocks.E) C) and D)
F) B) and D) B

Question 7

Use the theoretical Ramachandran plot at the top to evaluate the two experimental plots on the bottom. Describe the likely secondary structures found in each experimental plot.

Accepted Answer

The middle Ramachandran plot is consiste...

Question 8

The points in the Ramachandran plot are derived by

Accepted Answer

A)   counting the number of amino acids and placing points in allowed regions.
B)   measuring the  ϕ\phiϕ and  Ψ\PsiΨ angles in an experimentally determined protein crystal structure.
C)   placing each amino acid in regions commonly occupied by that amino acid.
D)   experimentally measuring the optical rotation of polarized light. E) B) and D)
F) None of the above

Question 9

Why is the amino acid proline not commonly found in $\alpha$-helices or $\beta$-sheets? In what secondary structure might proline be commonly found?

Accepted Answer

Because of its cyclic nature, proline has more restricted $\Psi$ and $\Psi$ angles. Also, because of its lack of an NH group on its backbone amine, proline cannot hydrogen bond to stabilize the helices or sheets. Proline can often be found in turns or loops connecting helices or strands.

Question 10

In the Anfinsen experiment with the unfolding of RNaseA, what order could the chemical reagents be removed in order to achieve an inactive protein?

Accepted Answer

A)   Remove denaturant first and reductant second.
B)   Simultaneously remove denaturant and reductant.
C)   Remove reductant first, denaturant second, and then finally add back reductant.
D)   Remove reductant first and denaturant second.E) All of the above
F) A) and B)

Question 11

Which class of protein structures does the protein shown below fit into?

Accepted Answer

A)   predominantly  α\alphaα -helical
B)   predominantly  β\betaβ -sheet
C)   intermixed  α\alphaα -helix and  β\betaβ -sheet
D)   domains of  α\alphaα -helix adjacent to domains of  β\betaβ -sheet E) A) and D)
F) A) and C)

Question 12

Which stabilizing force in protein tertiary structures is a covalent bonding force?

Accepted Answer

A)   ionic bonding
B)   disulfide bonding
C)   hydrophobic interactions
D)   van der Waals bondingE) B) and C)
F) A) and B) B

Question 13

Of the three proposed models of globular protein folding, which one describes the initial formation of all secondary structures, followed by the arrangement of those secondary structures into a final tertiary structure?

Accepted Answer

A)   mutant globule
B)   hydrophobic collapse model
C)   framework model
D)   nucleation modelE) B) and C)
F) A) and B)

Question 14

The amino acid with the neutral side chain at neutral pH is

Accepted Answer

A)   asparagine.
B)   aspartate.
C)   arginine.
D)   glutamate.E) B) and C)
F) B) and D)

Question 15

Identify the four images below, which represent the four classes of protein structures commonly identified across MOST structures found in the Protein Data Bank.

Accepted Answer

(a) Predominantly <img  loading="lazy" src="/assets/images/blured-textbook.svg" class="d-inline m-1" alt="blured image" width="139" height="30">-helical, (b...

Question 16

The chirality of naturally occurring amino acids in proteins is

Accepted Answer

A)   R.
B)   L.
C)   D.
D)   the same as glyceraldehyde.E) A) and B)
F) None of the above

Question 17

How many  β\betaβ -turns or  β\betaβ -loops are required to construct a  β\betaβ -sheet composed of four antiparallel strands?

Accepted Answer

A)   0
B)   3
C)   4
D)   5 E) A) and C)
F) B) and D)

Question 18

Which linear sequence of bonded atoms can be found in the backbone of polypeptides?

Accepted Answer

A)   C-N-N-C
B)   C-C-N-C
C)   N-C-C-C
D)   C-O-C-NE) C) and D)
F) A) and D)

Question 19

Which of the following statements about Ramachandran plots is true?

Accepted Answer

A)   They are good predictors of protein tertiary structure.
B)   They are needed to determine the secondary structure of a protein.
C)   They show equal distributions of  ϕ\phiϕ  and  Ψ\PsiΨ angles for  α\alphaα -helical and  β\betaβ -sheet containing proteins.
D)   They show that β\betaβ -sheets and  α\alphaα -helices occupy different  ϕ\phiϕ and  Ψ\PsiΨ  angles. E) A) and D)
F) None of the above

Question 20

In multi-subunit proteins, such as hemoglobin, the different subunits are usually bound to one another by all of the following EXCEPT

Accepted Answer

A)   hydrogen bonds.
B)   electrostatic interactions.
C)   hydrophobic interactions.
D)   peptide bonds.E) A) and B)
F) None of the above

Exam 4: Protein Structure

At the interface between subunits of a protein with quaternary structure, which of the following interactions between amino acid side chains would contribute to the stability of the dimer?

Correct Answer
verified

Which amino acid has the highest pKa?

Correct Answer
verified

Use the table below and write out the amino acid sequence coded by the following RNA sequence: AUG_CAC_AGG_UGA.

Correct Answer
verified

Which interaction largely stabilizes protein secondary (2 $\degree$ ) structures?

Correct Answer
verified

Which amino acid contains a hydroxyl group?

Correct Answer
verified

It is important for cells to degrade misfolded proteins. If misfolded proteins are not degraded, the misfolded proteins may

Correct Answer
verified
B

Use the theoretical Ramachandran plot at the top to evaluate the two experimental plots on the bottom. Describe the likely secondary structures found in each experimental plot.

Correct Answer
verified
The middle Ramachandran plot is consiste...
View Answer

Correct Answer
verified

Why is the amino acid proline not commonly found in $\alpha$ -helices or $\beta$ -sheets? In what secondary structure might proline be commonly found?

In the Anfinsen experiment with the unfolding of RNaseA, what order could the chemical reagents be removed in order to achieve an inactive protein?

Correct Answer
verified

Correct Answer
verified

Which stabilizing force in protein tertiary structures is a covalent bonding force?

Correct Answer
verified
B

Of the three proposed models of globular protein folding, which one describes the initial formation of all secondary structures, followed by the arrangement of those secondary structures into a final tertiary structure?

Correct Answer
verified

The amino acid with the neutral side chain at neutral pH is

Correct Answer
verified

Identify the four images below, which represent the four classes of protein structures commonly identified across MOST structures found in the Protein Data Bank.

Correct Answer
verified
(a) Predominantly -helical, (b...
View Answer

The chirality of naturally occurring amino acids in proteins is

Correct Answer
verified

How many $\beta$ -turns or $\beta$ -loops are required to construct a $\beta$ -sheet composed of four antiparallel strands?

Correct Answer
verified

Which linear sequence of bonded atoms can be found in the backbone of polypeptides?

Correct Answer
verified

Which of the following statements about Ramachandran plots is true?

Correct Answer
verified

In multi-subunit proteins, such as hemoglobin, the different subunits are usually bound to one another by all of the following EXCEPT

Correct Answer
verified

Exam 4: Protein Structure

At the interface between subunits of a protein with quaternary structure, which of the following interactions between amino acid side chains would contribute to the stability of the dimer?

Correct AnswerverifiedShow Answer

Which amino acid has the highest pKa?

Correct AnswerverifiedShow Answer

Use the table below and write out the amino acid sequence coded by the following RNA sequence: AUG_CAC_AGG_UGA.

Correct AnswerverifiedShow Answer

Which interaction largely stabilizes protein secondary (2 °\degree° ) structures?

Correct AnswerverifiedShow Answer

Which amino acid contains a hydroxyl group?

Correct AnswerverifiedShow Answer

It is important for cells to degrade misfolded proteins. If misfolded proteins are not degraded, the misfolded proteins may

Correct AnswerverifiedB

Use the theoretical Ramachandran plot at the top to evaluate the two experimental plots on the bottom. Describe the likely secondary structures found in each experimental plot.

Correct AnswerverifiedThe middle Ramachandran plot is consiste...View AnswerShow Answer

The points in the Ramachandran plot are derived by

Correct AnswerverifiedShow Answer

Why is the amino acid proline not commonly found in α\alphaα -helices or β\betaβ -sheets? In what secondary structure might proline be commonly found?

In the Anfinsen experiment with the unfolding of RNaseA, what order could the chemical reagents be removed in order to achieve an inactive protein?

Correct AnswerverifiedShow Answer

Which class of protein structures does the protein shown below fit into?

Correct AnswerverifiedShow Answer

Which stabilizing force in protein tertiary structures is a covalent bonding force?

Correct AnswerverifiedB

Of the three proposed models of globular protein folding, which one describes the initial formation of all secondary structures, followed by the arrangement of those secondary structures into a final tertiary structure?

Correct AnswerverifiedShow Answer

The amino acid with the neutral side chain at neutral pH is

Correct AnswerverifiedShow Answer

Identify the four images below, which represent the four classes of protein structures commonly identified across MOST structures found in the Protein Data Bank.

Correct Answerverified(a) Predominantly -helical, (b...View AnswerShow Answer

The chirality of naturally occurring amino acids in proteins is

Correct AnswerverifiedShow Answer

How many β\betaβ -turns or β\betaβ -loops are required to construct a β\betaβ -sheet composed of four antiparallel strands?

Correct AnswerverifiedShow Answer

Which linear sequence of bonded atoms can be found in the backbone of polypeptides?

Correct AnswerverifiedShow Answer

Which of the following statements about Ramachandran plots is true?

Correct AnswerverifiedShow Answer

In multi-subunit proteins, such as hemoglobin, the different subunits are usually bound to one another by all of the following EXCEPT

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Which interaction largely stabilizes protein secondary (2 $\degree$ ) structures?

Correct Answer
verified

Correct Answer
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Correct Answer
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B

Correct Answer
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The middle Ramachandran plot is consiste...
View Answer

Correct Answer
verified

Why is the amino acid proline not commonly found in $\alpha$ -helices or $\beta$ -sheets? In what secondary structure might proline be commonly found?

Correct Answer
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Correct Answer
verified

Correct Answer
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B

Correct Answer
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Correct Answer
verified

Correct Answer
verified
(a) Predominantly -helical, (b...
View Answer

Correct Answer
verified

How many $\beta$ -turns or $\beta$ -loops are required to construct a $\beta$ -sheet composed of four antiparallel strands?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
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