Which statement about quaternary structure is TRUE?
A) Quaternary structure is the position of subunits in the overall structure of a protein.
B) All proteins have quaternary structure.
C) Quaternary structure is unaffected by acids or heat.
D) Quaternary structure is determined by the same interaction that holds an α-helix together.
E) Quaternary structure is how prosthetic groups are held in a protein.

Question

Quizplus · Accepted Answer

Quaternary structure refers to the arrangement and interaction of multiple polypeptide chains (subunits) in a protein that has more than one chain. It is about how these subunits come together to form the functional protein complex. Not all proteins have quaternary structure; it is specific to those proteins that are made up of more than one polypeptide chain. Quaternary structure can be affected by environmental conditions such as pH and temperature, and it is determined by a variety of interactions, including hydrogen bonds, ionic bonds, and hydrophobic interactions, rather than just the interactions that stabilize α-helices. Prosthetic groups are non-polypeptide components that proteins may have, but their relationship with the protein is not what defines quaternary structure.

Which Statement About Quaternary Structure Is TRUE