Gateway Technical College BIO 806-177 Lecture 6 : Protein Assemblies: 1)Chaperones like GroEL/GroES facilitate protein folding by which of the following? Preventing aggregation of proteins trapped in deep local minima of the free energy landscape Modifying the energy landscape of a folded protein so that otherwise high energy statates are stabilized Catalyzing the breaking of incorrectly paired disulfide bonds in proteins Catalyzing the formation of trans peptide bonds in proteins Which enzyme or enzyme family is responsible for correcting incorrectly formed disulfides in misfolded proteins? Prolyl Isomerase GroEL/GroES Heat-shock proteins Protein disulfide Isomerase Which of the following symmetries is NOT an example of point symmetry? C symmetry Helical Symmetry Cubic Symmetry Icosahedral Symmetry A symmetric assembly is known to contain exactly FOUR identical subunits

Gateway Technical College

BIO 806-177

Lecture 6 : Protein Assemblies:

1)Chaperones like GroEL/GroES facilitate protein folding by which of the following?

1. 1. Preventing aggregation of proteins trapped in deep local minima of the free energy landscape
   2. Modifying the energy landscape of a folded protein so that otherwise high energy statates are stabilized
   3. Catalyzing the breaking of incorrectly paired disulfide bonds in proteins
   4. Catalyzing the formation of trans peptide bonds in proteins
2. Which enzyme or enzyme family is responsible for correcting incorrectly formed disulfides in misfolded proteins?
   1. Prolyl Isomerase
   2. GroEL/GroES
   3. Heat-shock proteins
   4. Protein disulfide Isomerase
3. Which of the following symmetries is NOT an example of point symmetry?
   1. C symmetry
   2. Helical Symmetry
   3. Cubic Symmetry
   4. Icosahedral Symmetry
4. A symmetric assembly is known to contain exactly FOUR identical subunits. Which of the following symmetry groups could the protein adopt?

(i) C2 (ii) C4 (iii) D2 (iv) D4

4. 1. (i) only
   2. (i) or (ii)
   3. (iii) only
   4. (ii) or (iii)
   5. (iv) only
5. Which of the following statements about the “energy landscape model” of protein folding is NOT correct?
   1. It provides a resolution to Leventhal’s paradox
   2. There may be several pathways of intermediate structures in going from an unfolded to a natively folded protein
   3. A folding protein explores the majority of all possible confirmations before reaching the native state
   4. There are stable intermediates corresponding to local minima in the energy landscape
6. Which of the most common symmetry is seen in nature?
   1. C2
   2. C3
   3. D2
   4. Helical
7. Which of the following statements about amyloid fibrils is NOT true?
   1. They primarily consist of beta strands
   2. They adopt a helical symmetric arrangement
   3. They form rapidly following an initial nucleation event
   4. They occur when a natively folded protein aggregates in the cell