1-6. Use this segment of a protein:
1-2. Write the sequence of the segment:         cysteine-leucine-asparagine-glycine or Cys-Leu-Asn-Gly or C-L-N-G          

3-4. Is this more likely to represent part of an α-helix or part of a β-pleated sheet? Choose one difference between the two that would allow you to decide.

I tried to suggest a β-pleated sheet by having the side chains alternating up and down, but no one noticed that.
Both an &alpha-helix and a β-pleated sheet are stabilized by hydrogen bonds between backbone atoms, so that's a similarity, not a difference.
Two of the residues are classified as polar uncharged (C and N), while two are classified as nonpolar (L and G). The fact that the character (nonpolar/polar) alternates is more characteristic of a β-pleated sheet than an α-helix, as the side chains in a β-pleated sheet alternate up and down.
The simplest answer requires remembering that G is rarely part of an α-helix.
It's true that C and G don't form hydrogen bonds, but neither do they repel each other.

5-6. Name a bond or interaction that part of this segment would have to help stabilize tertiary structure only (not primary or secondary), and circle the relevant part of the structure.

Everyone chose formation of a disulfide bond and correctly circled the SH part of the C side chain.
Other correct choices include hydrophobic interactions (circle Leu side chain or the Gly side chain) or hydrogen bonds with the Asn side chain.

7-10. Each phrase below describes (M) myoglobin only, (H) hemoglobin only,
(B) both proteins, or (N) neither. A letter may be used more than once or not at all.

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