Question 1

What is the pI of the dipeptide shown? (Use the pK as given.)

Accepted Answer

A)   0
B)   5
C)   9
D)   10.5

Question 2

In the multi-subunit protein family called immunoglobulins, the different subunits are held together by both covalent and noncovalent forces. What are the covalent forces that hold subunits together in immunoglobulins?

Accepted Answer

Cysteine disulfide b...

Question 3

What is a current hypothesis that explains the infectious nature of prion diseases?

Accepted Answer

A)   The virus responsible for prion diseases is transmissible.
B)   Unfavorable environmental factors negatively influence healthy cells.
C)   The small molecule denaturants found in infected cells are passed on to healthy cells.
D)   The presence of an improperly folded prion protein promotes the misfolding of normal prion proteins.

Question 4

Use the table below and the following RNA sequence to determine which reading frame would give rise to the shortest peptide, or which reading frame gives rise to the first stop codon.
Frame: 1 2 3
RNA: GCG CCC CCU AAC AGG UAG CUG CGG UUC CUG

Accepted Answer

Frame 3: Beginning w...

Question 5

What is the difference between clamp-type and chamber-type chaperone proteins?

Accepted Answer

A)   One uses ATP and the other does not.
B)   One folds proteins, whereas the other just protects them from unfolding.
C)   They are shaped differently.
D)   One type is found extracellularly and one intracellularly.

Question 6

Describe the proposed model of globular protein folding called the nucleation model.

Accepted Answer

In the nucleation model of globular prot...

Question 7

Trace directly the covalently bonded backbone atoms from the N to C terminus of a dipeptide. Which atoms are found in this trace?

Accepted Answer

A)   NCCNCC
B)   NCCONCCO
C)   NCONCO
D)   CNCCNC

Question 8

All of the following are stabilizing forces in maintaining a stable protein tertiary (3 °\degree° )  structure, EXCEPT

Accepted Answer

A)   H bonds.
B)   temperature.
C)   hydrophobic interactions.
D)   electrostatic attractions.

Question 9

Which of the following statements about the clamp-type chaperone protein Hsp70 is correct?

Accepted Answer

A)   Hsp70 uses ATP binding and hydrolysis energy to assist in the folding of a protein.
B)   Hsp70 is a multi-subunit protein shaped like a large barrel, inside of which the folding protein is protected.
C)   Hsp70 is most active during cell division phases.
D)   Hsp70 assists in protein unfolding by hydrolyzing and remaking the protein peptide bonds.

Question 10

Of the 20 common amino acids, how many have a chiral  α\alphaα -carbon?

Accepted Answer

A)   0
B)   1
C)   19
D)   20

Question 11

Using the pKas shown, what is the isoelectric point of the amino acid tyrosine?

Accepted Answer

A)   
B)   5.5
C)   7.0
D)   9.75

Question 12

The peptide bond

Accepted Answer

A)   is most stable in the cis configuration.
B)   has a mix of single and double bond characters.
C)   can rotate around the carbonyl and N bond but not around the  α\alphaα -carbon and N bond.
D)   can function as a weak acid and weak base.

Question 13

Christian Anfinsen showed in a famous experiment that it is possible to unfold a protein and refold it to obtain a functional protein. Which two reagents were used in this experiment to unfold the protein?

Accepted Answer

A)   detergent and salt
B)   urea and  β\betaβ -mercaptoethanol
C)   acid and base
D)   ethanol and  β\betaβ -mercaptoethanol

Question 14

Draw the resonance structures that stabilize the peptide bonds found in proteins.

Accepted Answer

The answer of Draw the resonance structures that stabilize the...

Question 15

Use the two-stranded antiparallel $\beta$-sheet below and drawn in a $\beta$-turn.

Accepted Answer

The answer of Use the two-stranded antiparallel $\beta$-sheet below and...

Question 16

The common protein fold shown below is the fold.

Accepted Answer

A)   "Greek key"
B)   "Rossman"
C)   "FERM domain"
D)   " α\alphaα / β\betaβ  barrel"

Question 17

What is the minimum number of amino acids needed to make one turn of an  α\alphaα -helix?

Accepted Answer

A)   3
B)   4
C)   6
D)   7

Question 18

What is believed to be the underlying cause of prion protein plaque formation?

Accepted Answer

A)   The PrPSc proteins are misfolded and aggregated from PrPc proteins.
B)   The unstructured N-terminal region of PrPc is thought to remain unfolded.
C)   The normal PrPc proteins are aggregated.
D)   The PrPSc protein adheres to and inhibits cell membranes.

Question 19

At what point does the isoelectric point or pI occur?

Accepted Answer

A)   when all of the acidic protons are neutralized with base
B)   at pH = 7.0
C)   at the pH when all negative charges on a zwitterion counter the positive charges
D)   when the molecule has a single electric charge

Question 20

The essential amino acids in adult humans are those that are required in our diet because of a lack of the biosynthetic pathway in our cells. The single-letter abbreviations for these amino acids are WVMILKFHT. Name these amino acids.

Accepted Answer

Tryptophan, valine, methionine...

Exam 4: Protein Structure

Use the two-stranded antiparallel β\betaβ -sheet below and drawn in a β\betaβ -turn.

Correct AnswerverifiedShow Answer

What is the pI of the dipeptide shown? (Use the pK as given.)

Correct AnswerverifiedShow Answer

At what point does the isoelectric point or pI occur?

Correct AnswerverifiedShow Answer

Using the pKas shown, what is the isoelectric point of the amino acid tyrosine?

Correct AnswerverifiedShow Answer

What is a current hypothesis that explains the infectious nature of prion diseases?

Correct AnswerverifiedShow Answer

All of the following are stabilizing forces in maintaining a stable protein tertiary (3 °\degree° ) structure, EXCEPT

Correct AnswerverifiedShow Answer

The peptide bond

Correct AnswerverifiedShow Answer

In the multi-subunit protein family called immunoglobulins, the different subunits are held together by both covalent and noncovalent forces. What are the covalent forces that hold subunits together in immunoglobulins?

Correct AnswerverifiedCysteine disulfide b...View AnswerShow Answer

Which of the following statements about the clamp-type chaperone protein Hsp70 is correct?

Correct AnswerverifiedShow Answer

The common protein fold shown below is the fold.

Correct AnswerverifiedShow Answer

What is the minimum number of amino acids needed to make one turn of an α\alphaα -helix?

Correct AnswerverifiedShow Answer

Draw the resonance structures that stabilize the peptide bonds found in proteins.

Correct AnswerverifiedShow Answer

The essential amino acids in adult humans are those that are required in our diet because of a lack of the biosynthetic pathway in our cells. The single-letter abbreviations for these amino acids are WVMILKFHT. Name these amino acids.

Correct AnswerverifiedTryptophan, valine, methionine...View AnswerShow Answer

Christian Anfinsen showed in a famous experiment that it is possible to unfold a protein and refold it to obtain a functional protein. Which two reagents were used in this experiment to unfold the protein?

Correct AnswerverifiedShow Answer

Use the table below and the following RNA sequence to determine which reading frame would give rise to the shortest peptide, or which reading frame gives rise to the first stop codon. Frame: 1 2 3 RNA: GCG CCC CCU AAC AGG UAG CUG CGG UUC CUG

Correct AnswerverifiedFrame 3: Beginning w...View AnswerShow Answer

What is believed to be the underlying cause of prion protein plaque formation?

Correct AnswerverifiedShow Answer

Of the 20 common amino acids, how many have a chiral α\alphaα -carbon?

Correct AnswerverifiedShow Answer

Describe the proposed model of globular protein folding called the nucleation model.

Correct AnswerverifiedIn the nucleation model of globular prot...View AnswerShow Answer

What is the difference between clamp-type and chamber-type chaperone proteins?

Correct AnswerverifiedShow Answer

Trace directly the covalently bonded backbone atoms from the N to C terminus of a dipeptide. Which atoms are found in this trace?

Correct AnswerverifiedShow Answer

Use the two-stranded antiparallel $\beta$ -sheet below and drawn in a $\beta$ -turn. $Use the two-stranded antiparallel \beta -sheet below and drawn in a \beta -turn.$

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

All of the following are stabilizing forces in maintaining a stable protein tertiary (3 $\degree$ ) structure, EXCEPT

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Cysteine disulfide b...
View Answer

Correct Answer
verified

The common protein fold shown below is the fold. $The common protein fold shown below is the fold. A) Greek key B) Rossman C) FERM domain D) \alpha / \beta barrel$

Correct Answer
verified

What is the minimum number of amino acids needed to make one turn of an $\alpha$ -helix?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Tryptophan, valine, methionine...
View Answer

Correct Answer
verified

Correct Answer
verified
Frame 3: Beginning w...
View Answer

Correct Answer
verified

Of the 20 common amino acids, how many have a chiral $\alpha$ -carbon?

Correct Answer
verified

Correct Answer
verified
In the nucleation model of globular prot...
View Answer

Correct Answer
verified

Correct Answer
verified