How many amino acids are per turn in an alpha helix secondary structure?

Which of the following amino acids is least likely to be found in the middle of an alpha helix?

Which of the following are true of beta bends in protein structures?

I. Beta bends are secondary protein structures.

II. Beta bends consist of sequences of four amino acids.

III. In beta bends amino acids proline and glycine are common.

IV. Hydrogen and ionic bonds stabilize beta bends.

What is the only level of protein structure that does not involve covalent bonding?

Referring to the secondary structure of proteins, proline is necessary for which of the following?

What type of bonds are the "backbone" of secondary protein structure?

Which of the following statements are true about motifs in a protein structure?

I. The most common motif is beta-alpha-beta, when an alpha helix connects two parallel strands of a beta sheet.

II. Motifs are usually composed of more than one form of secondary structure.

III. Motifs are supersecondary structures.

IV. Motifs are combinations of alpha helices and beta sheets.

The stabilization of secondary structure in polypeptides is conferred by which of the following?

With respect to proteins, alpha structures are __________ and beta structures are __________.

What is the hydrogen bonding pattern within an alpha helix?