Amino Acids And Proteins

Front 1

The unique cyclic structure of which of the following amino acids plays a central role in the formation of alpha helices and beta sheets?

Back 1

Proline

Front 2

Electrophoretic separation of leucine from a protein sample would be least effective at which of the following pH values?

• 2.4
• 1.4
• 0.4
• 7.4

Back 2

7.4

Front 3

Electrophoretic separation at pH 6 of a sample of polypeptide 1 (mw 100) polypeptide 2 (mw 200) and polypeptide 3 (mw 400) would result in which of the following (note: the isoelectric point of each polypeptide occurs at pH 6)

• Polypeptide 3 would move the farthest
• Polypeptide 1 would move the farthest
• Polypeptide 2 would move the farthest
• None of the polypeptides would move
  

Back 3

None of the polypeptides would move

Front 4

The alpha helix is an example of which of the following structural properties of proteins?

Back 4

Secondary structure

Front 5

All hydrophobic amino acids (valine, leucine, isoleucine, etc.) share which of the following properties?

Back 5

Nonpolar uncharged R groups