Protein Structure and Function Quiz

Which type of weak interaction is most important for cohesiveness and strength between beta-strands in beta-sheets?

• Ionic

• Hydrophobic

• Covalent

• Hydrogen bonds

• van der Waal's interactions

Which amino acid would most likely be found in the interior of a globular protein?

How many of the 20 common amino acids have rings in their structures?

• 2

• 3

• 4

• 5

• 6

What is the highest level of protein structure in human insulin, which has two polypeptides of different mass linked by several disulfide bonds?

• Primary

• Secondary

• Tertiary

• Quaternary

What specific functional group is used to form disulfide bonds?

• Carboxyl

• Carbonyl

• Sulfhydryl

• Phosphoryl

• Guanidino

Which term refers to molecules like proteins, which can have both polar and nonpolar regions?

• Amphipathic

• Amphigenic

• Amphibolic

• Amphiphatic

• Amphoteric

Given that all 20 common amino acids have at least two oppositely charged, ionizable R-groups, which statement below is incorrect?

• Solutions of amino acids can act as buffers.

• All amino acids are zwitterions.

• All amino acids carry at least one charge across the full range of their titration curves.

• Amino acid isoelectric points should be near neutrality.

• It is not possible to fully deprotonate amino acids.

If a protein is denatured, what is lost?

• Some of the weak interactions

• Tertiary structure

• Function

• Only A and B above

• A, B, and C above

The primary structure of a protein is known and the location of internal disulfide bonds has been determined. How could one predict whether there might be secondary structures in my protein once it folds into a native conformation?

• Perform X-ray diffraction on my protein

• Perform a Ramachandran plot/analysis on my protein

• Run two-dimensional gel electrophoresis on my protein

• Determine if there is more than one polypeptide in the protein

• Identify specific motifs in the primary structure

What important function do molecular chaperones perform?