Proteins have four levels of structure: primary (amino acid sequence), secondary (local folding patterns like alpha helices and beta sheets), tertiary (overall 3D shape), and quaternary (assembly of ...

Proteins are the workhorses of cells. Learn how their functions are based on their three-dimensional structures, which emerge from a complex folding process.

Proteins are necessary for many bodily processes. Numerous physiological functions and activities are carried out by thousands of distinct proteins.