Exam 6: Proteins: Three-Dimensional Structure

Matching -________ is a fibrous protein that contains a hydrophobic amino acid approximately every 4 residues which forms an α helix with one hydrophobic side.

Matching -Repeating values of $\phi$ and $\varPsi$ make up predictable orientations of amino acid with a chain,this predictable orientation forms___________.

The low pH found in the gut can enhance the digestibility of dietary protein by causing ___.

Noncovalent forces that stabilize protein structure include all of the following except __________.

Which of the following would be most stable based on the information you have learned about protein structure?

Which of the following gives the best example of a nonrepetitive structure in a protein?

Which of the following structural proteins has the greatest elasticity?

The first step in the folding of disordered polypeptides into ordered functional protein is the formation of ______.

Which of the following has (have)both a favorable hydrogen bonding pattern and $\phi$ and $\varPsi$ values that fall within the allowed Ramachandran conformational regions?

Of the following,which amino acid is most likely to be found in position 1 or 4 on α keratin?

Which of the following is true regarding crystalline proteins?

Proteins can denature due to a change in

Examine the three sequences below for collagen-like proteins.If hydrogen bonding were the most important feature in determining strength in fibrous proteins,which of the following sequences likely has the highest melting temperature and why? (Note: Flp = fluoroproline;Hyp = hydroxyproline) (I)Pro-Hyp-Gly-Pro-Hyp-Gly-Pro-Hyp-Gly (II)Pro-Flp-Gly-Pro-Flp-Gly-Pro-Flp-Gly (III)Gly-Pro-Thr-Gly-Pro-Thr-Gly-Pro-Thr

Conventional one dimensional NMR spectroscopy is not generally an effective tool for determination of protein structure because… (I)Proteins (including small proteins)have a high number of hydrogen atoms. (II)NMR requires a high quality protein crystal. (III)The NMR spectra exhibit high peak overlap.

Matching -The strength of _______ comes from close packing of glycine residues and the characteristics of hydroxyproline allowing formation of a left- handed helical conformation which combines with two other left handed structures to form a right-handed triplet helix.

Matching -In a ______,the $\phi$ and $\varPsi$ angles of the peptide backbone would orient atoms closer than their van der Waals distance.

The Protein Data Bank (PDB)is a database provides structural information about proteins that may be useful for which of the following? (I)A researcher studying the changes in protein fold associated with prions. (II)A researcher classifying structural elements by function. (III) A researcher designing a compound to bind tightly to a particular region in the protein.

Which of the following changes would not alter the functional characteristics of α keratin?

In a protein,the most conformationally restricted amino acid is ______;the least conformationally restricted is ______.

What observation about protein refolding or renaturation helped to solidify the connection between primary amino acid sequence and 3-D structure?