Exam 4: The Three-Dimensional Structure of Proteins

Experiments on denaturation and renaturation after the reduction and reoxidation of the -S-S- bonds in the enzyme ribonuclease (RNase) have shown that:

What are two mechanisms by which "chaperone" proteins assist in the correct folding of polypeptides?

Which amino acid is MOST likely to be found outside of the highlighted/shaded regions on a Ramachandran plot?

Explain how circular dichroism spectroscopy could be used to measure the denaturation of a protein.

Which statement about protein folding is NOT true?

How does one determine the three-dimensional structure of a protein? Your answer should be more than the name of a technique.

Two proteins, X and Y, have similar tertiary structures. The quaternary structures of the proteins are indicated by the diagram below. What differences can be expected in the surfaces of the polypeptides X and Y?

The secondary structure shown below is an example of a(n):

A repeating structural unit in a multimeric protein is known as a(n):

Proteins often have regions that can fold and function as an independent entity from the whole protein. These regions are called:

Briefly describe the process by which a protein aggregate is degraded by autophagy.

Disulfide bonds are more likely to be formed _____ of the cell, due to the _____ environment there.

How can changes in pH alter the conformation of a protein?

If a protein is not folded correctly or becomes partially unfolded, what could NOT be a consequence?

Which statement is FALSE?

Which of the images below depict a protein-folding pathway with no stable folding intermediates?

Which interactions are NOT considered to be "weak" in proteins?

The difference between the stretching ability of silk and wool fibers, low and high ability to stretch, respectively, is due to their protein components. Which statement CORRECTLY attributes the secondary structure contributions to this stretch ability?

The major reason that antiparallel $\beta$ -stranded protein structures are more stable than parallel $\beta$ -stranded structures is that the latter:

What is the rationale for many large proteins containing multiple copies of a polypeptide subunit?