Which of the following is NOT a level of protein structure?

Prepare for the Foundations of Biology Exam 1. Dive into key biological concepts with multiple choice questions, hints, and explanations. Ace the exam with our efficient study methods!

Multiple Choice

Which of the following is NOT a level of protein structure?

Protein structure is described in four main levels: the linear sequence of amino acids forms the primary structure; local regular folds like alpha helices and beta sheets constitute secondary structure; the overall 3D arrangement of a single polypeptide chain is tertiary structure; and the organization of multiple polypeptide chains into a multi-subunit complex is quaternary structure. Quintary isn’t a standard level of protein structure. There isn’t a formal fifth level in the classical framework. Sometimes people talk about quinary interactions to describe transient, high-level associations in crowded cellular environments, but that isn’t counted as a formal structural level like the others. So the choice that doesn’t fit is quintary.

Protein structure is described in four main levels: the linear sequence of amino acids forms the primary structure; local regular folds like alpha helices and beta sheets constitute secondary structure; the overall 3D arrangement of a single polypeptide chain is tertiary structure; and the organization of multiple polypeptide chains into a multi-subunit complex is quaternary structure. Quintary isn’t a standard level of protein structure. There isn’t a formal fifth level in the classical framework. Sometimes people talk about quinary interactions to describe transient, high-level associations in crowded cellular environments, but that isn’t counted as a formal structural level like the others. So the choice that doesn’t fit is quintary.

More practice questions