Which of the following statements about protein structure is correct?
A) Disulfide interactions are required for the stability of globular structures.
B) Hydrophobic sidechains commonly occur clustered in interior areas of globular proteins.
C) The alpha-helix is maintained chiefly by hydrophobic interactions.
D) Covalent linkages between the protomeric chains are a common feature of globular oligomeric proteins such as hemoglobin and lactate dehydrogenase (LDH).
E) Pleated-sheet structures are found only in fibrous proteins.

Question

Quizplus · Accepted Answer

Hydrophobic sidechains are attracted to each other in order to minimize contact with water molecules, and hence, they are commonly found in interior areas of globular proteins to form a hydrophobic core. Disulfide interactions can contribute to protein stability, but they are not required for globular structure. Alpha-helices are chiefly maintained by hydrogen bonding, while covalent linkages between protein subunits are not required for globular structure. Pleated-sheet structures are found in both fibrous and globular proteins.

Which of the Following Statements About Protein Structure Is Correct