Question

Protein molecules that have a quaternary structure must have two or more of which of the following?

Choose one:
A. protein domains
B. binding sites
C. α helices and β sheets
D. polypeptide chains
E. disulfide bonds

Answer 1

Protein molecules with a quaternary structure must have two or more polypeptide chains, which interact through various types of bonds to form the protein's structure.

Step-by-step explanation:

Protein molecules that have a quaternary structure must have two or more polypeptide chains. The quaternary structure is the arrangement of multiple polypeptide subunits in a protein, which can be identical or different. These subunits are held together by various types of bonds and interactions, including hydrogen bonds, ionic bonds, disulfide linkages, and dispersion forces.

Proteins such as hemoglobin, which is found in red blood cells, consist of four tertiary polypeptides -- two alpha chains and two beta chains, each containing an iron-based heme. These interactions give the protein its structure and function.