Exam 4: The Three-Dimensional Structure of Proteins

Any given protein is characterized by a unique amino acid sequence (primary structure) and three-dimensional (tertiary) structure. How are these related?

Describe a reservation about the use of x-ray crystallography in determining the three-dimensional structures of biological molecules.

Proteostasis is the cellular process by which:

The three-dimensional conformation of a protein may be strongly influenced by amino acid residues that are very far apart in sequence. This relationship is in contrast to secondary structure, where the amino acid residues are:

In an $\alpha$ helix, the R groups on the amino acid residues:

Which image below shows that there are folding intermediates with substantial stability along nearly every folding pathway?

Explain what is meant by motifs in protein structure.

The MOST important contribution to the stability of a protein's conformation appears to be the:

Pauling and Corey showed that in small peptides, six atoms associated with the peptide bond all lie in a plane. On a dipeptide of two amino acids in trans linkage (side-chains can be shown as -R), which six atoms are part of the planar structure of the peptide bond?

Of the following bonds, which have freedom of rotation? I. N - C _$\alpha$ II) C _$\alpha$ - C III) C - N IV) R - C _$\alpha$

Which factor is LEAST likely to result in protein denaturation?

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

The structural classification of proteins (based on motifs) is based primarily on their:

Pauling and Corey's studies of the peptide bond showed that:

Which statement concerning protein domains is TRUE?

In the $\alpha$ helix, the hydrogen bonds:

Roughly how many amino acids are there in one turn of an $\alpha$ helix?

A _____ protein will often have properties that allow it to be both strong and flexible.

Name four factors (bonds or other forces) that contribute to stabilizing the native structure of a protein, and describe one condition or reagent that interferes with each type of stabilizing force.

A salt bridge would be MOST likely to be found: