[Lec 3] iClicker Questions: Structure of Proteins

Question 1

Which of the following statements is true:

A) Neutral polar amino acids and neutral nonpolar amino acids will likely be buried in the center of a protein

B) Neutral polar amino acids and neutral nonpolar amino acids will likely be exposed on the surface of a protein

C) Neutral polar amino acids will likely be buried in the center of a protein and neutral nonpolar amino acids will likely be on the surface

D) Neutral polar amino acids will likely be on the surface of a protein and neutral nonpolar amino acids will likely be buried in the center of a protein

Answer 1

d.

Question 2

A protein that is rich in basic amino acids would be predicted to have:

A) A net negative charge

B) No net charge

C) A net positive charge

Answer 2

c.

Question 3

Below is the amino acid sequence for one subunit of chorionic gonadotropin (the hormone commonly detected by pregnancy tests). Based on its sequence, do you expect it to form disulfide bonds?

A) No, it will never form disulfide bonds

B) Yes, it will always have disulfide bonds

C) Yes, but only when it is in the cytoplasm

D) Yes, but only when it has been secreted out of the cell

Answer 3

d.

Question 4

Many signaling and receptor molecules at the cell’s surface are embedded in the cell membrane. Which amino acid(s) would be most suitable for inserted on into the lipid bilayer?

A) acidic

B) basic

C) Neutral non-polar

D) Neutral polar

Answer 4

c.

Question 5

You encounter a protein with a short region with the following sequence “L- V-V-L-M-M-I-L-A-G-G-L”. This region of the protein is most likely

A) Alpha Helix
B) Beta Sheet
C) Has no secondary structure

Answer 5

a.

Question 6

You encounter a second protein with a short region with the following sequence “L-V-P-L-M-M-I-L-P-G-G-L”. This region of the protein is most likely

A) Alpha Helix
B) Beta Sheet
C) Has no secondary structure

Answer 6

c.

Question 7

Which of the following amino acids would be found buried in the protein?

A) Glutamine (Q)

B) Isoleucine (I)

C) Aspartate (D)

D) Lysine (K)

Answer 7

b.

Question 8

DNA binding proteins have amino acids that interact with various aspects of the double helix. Determine which amino acid(s) would be most suitable for each interacted on:

A) Forming a salt bridge (ionic bond) with the DNA backbone

B) IntercalaDng between stacked base pairs

C) Sampling the chemical signature of the major groove

Answer 8

c.