Gateway Technical College

BIO 806-177

Lecture 4 : Protein Folds

1)Which of the following best describes the geometry of an alpha helix?

1. 1. A left handed helix with ~3.6 residues per turn
   2. A right handed helix with ~3.6 residues per turn
   3. A left handed helix with ~3.0 residues per turn
   4. A right handed helix with ~3.0 residues per turn
2. In which secondary structure arrangement does a single residue make TWO hydrogen bonds with the SAME residue?
   1. Alpha helix
   2. 3_10 Helix
   3. Parallel beta strands
   4. Antiparallel beta strands
3. Ramachandran maps are similar for all amino acids with two exceptions: glycine and proline. How do the Ramachandran maps of these two compare to the general case?
   1. Glycine has more allowed conformations; proline has fewer
   2. Glycine has fewer allowed conformations; proline has more
   3. Both have more allowed conformations
   4. Both have fewer allowed conformations
4. Which of the following are NOT an example of fibrous protein?
   1. Alpha keratin
   2. Collagen
   3. Myoglobin
   4. All of the above are fibrous proteins
5. Which of the following proteins do NOT contain alpha helices?
   1. Myoglobin
   2. Collagen
   3. Alpha Keratin
   4. Triosephosphate Isomerase
6. Which of the following sequences would you expect to find in the CORE of a globular protein?
   1. DERST
   2. GQERR
   3. KYSKT
   4. VLFAI
7. Which of the following statements are TRUE regarding the energetics of globular protein folding?
   1. Folded proteins bury hydrophobic residues in protein core to maximize the entropy of solvent (water)
   2. In going from a random coil to a folded protein, the entropy of the polypeptide chain decreases
   3. The enthalpy changes that occur in protein folding are mostly due to noncovalent interactions
   4. All of the above are true
8. Which of the following methods is NOT a method for denaturing a folded protein?
   1. Addition of urea
   2. Decreasing the protein concentration
   3. Changing the pH
   4. Increasing the temperature