Identifying Protein Structures

Identify the secondary structure (α helix, β-pleated sheet, or triple helix) described in each of the following statements:
a.   a structure that has hydrogen bonds between adjacent polypeptide chains
b.   three helical polypeptides woven together
c.   a peptide chain with a coiled or corkscrew shape that is held in place by hydrogen bonds

---

Which attractive force holds secondary structures together in proteins?

---

Indicate the type of protein structure.
   primary                  α-helix
   β-pleated sheet            triple helix   

A.  polypeptide chains held side by side by H bonds
B.  sequence of amino acids in a polypeptide chain
C.  corkscrew shape with H bonds between amino acids
D.  three peptide chains woven like a rope