Exam 4: Protein Structure

After analyzing all the structures of proteins found in the Protein Data Bank,scientists have found that four general classes of protein structures exist,based on their secondary structure themes.Name the four classes of general protein structures.

Shown is the titration curve for the amino acid aspartic acid.Draw the predominant protonation state of aspartic acid found at point A in the curve.

The peptide bond is stronger than the ester bond.What structural feature of the peptide bond gives it additional bond strength?

In the multi-subunit protein family called immunoglobulins,the different subunits are held together by both covalent and noncovalent forces.What are the covalent forces that hold subunits together in immunoglobulins?

What do Ramachandran plots show?

All of the following are stabilizing forces in maintaining a stable protein tertiary (3 )structure,EXCEPT

Which amino acid has the highest pKa?

Use the table below and write out the amino acid sequence coded by the following RNA sequence: AUG_CAC_AGG_UGA.

Which amino acid contains a hydroxyl group?

Cystic fibrosis results from the misfolding of proteins that never get the chance to properly insert into the membranes of lung epithelial cells and perform their function.This is generally referred to as a __________ disease.

In a standard -helix,__________ H bonds and __________ dipole moments are found per amino acid,which stabilizes the -helical structure.

Use the table below and the following RNA sequence to determine which reading frame would give rise to the shortest peptide,or which reading frame gives rise to the first stop codon. Frame: 1 2 3 RNA: GCG CCC CCU AAC AGG UAG CUG CGG UUC CUG

What is the approximate net charge of the molecule shown below at pH 7?

List reagents and conditions that denature proteins.

Of the 20 common amino acids,how many have a chiral -carbon?

Protein secondary structures such as -helices and -sheets are stabilized mainly by

How many possible protein primary structures are there for a tripeptide given the 20 amino acids?

For the alanine titration curve shown below,which best describes point A?

The peptide bond

Which of the following statements regarding protein domains is true?