How do proteins achieve their tertiary structure?

Proteins achieve their tertiary structure primarily through interactions between the side chains of amino acids, also known as R groups. These side chains can engage in various types of interactions, including hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges. The unique properties and structures of these side chains determine how the protein folds into its three-dimensional shape, which is crucial for its functionality.

The specific sequence of amino acids in a protein (the primary structure) dictates how the protein will fold into its tertiary structure. These interactions promote the folding of the protein into a conformation that is stable and functional. The tertiary structure is essential for the biological activity of the protein, as it determines the orientation of any active sites or binding sites required for the protein's role.

While other factors, such as covalent bonding and external environmental conditions like temperature, can influence protein stability and folding, it is the interactions among the side chains that predominantly dictate the overall tertiary structure of the protein.