Final answer:
The tertiary protein structure is the three-dimensional shape of a protein determined by side chain interactions, crucial for its biological function.
Step-by-step explanation:
The tertiary protein structure refers to the complex three-dimensional folding pattern of a protein, which is a result of interactions between the amino acid side chains. It encompasses various secondary structures like alpha helices and beta sheets in addition to regions with more random coil configurations. These elements come together to create the overall shape of the protein. Interactions such as disulfide bridges, hydrogen bonds, ionic bonds, and hydrophobic interactions work collectively to establish the protein's final three-dimensional form. This structure is critical because it is strongly linked to the protein's biological function. For example, the protein insulin has a specific tertiary structure essential for its role in regulating blood glucose levels.