Structure and Properties of Peptides Objective Questions and Answers

1. Hydrogen bonds in a-helices are

2. The peptide bond in proteins is

B. usually cis unless proline is the next amino acid

C. usually trans unless proline is the next amino acid

D. is planar because of steric hinderance

3. The molecular formula for glycine is C2H5O2N. What would be the molecular formula for a linear oligomer made by linking ten glycine molecules together by condensation synthesis?

4. Which of the following is an example of tertiary structure in a protein?

A. A multimeric protein

5. The peptide, Val-Lys-Glu-Met-Ser-Trp-Arg-Ala, was digested with cyanogen bromide (CNBr) to produce:

A. Val-Lys + Glu-Met-Ser + Trp-Arg-Ala

B. Val-Lys-Glu-Met-Ser-Trp + Arg-Ala

C. Val-Lys-Glu-Met + Ser-Trp-Arg-Ala

D. Val-Lys-Glu + Met-Ser-Trp-Arg-Ala

Discussion

6. In deoxy hemoglobin (Hb), the Fe (II) is coordinated to

A. four nitrogens of heme, the proximal His, and a water molecule

B. four nitrogens of heme and to a water molecule

C. two nitrogens of heme and to three His residues in Hb

D. two nitrogens of heme and to three water molecules

Discussion

7. In the β-pleated sheet

A. hydrogen bonds are formed between the peptide bonds

B. adjacent polypeptide chains can either be parallel or antiparallel

C. the polypeptide chain is fully extended

D. all of the above

Discussion

Structure and Properties of Peptides MCQs