To understand how a protein gets its final shape or conformation, we need to understand the four levels of protein structure: primary, secondary, tertiary, and quaternary.

Each protein has a specific cellular function, ranging from catalysis to structural integrity. This specific functions are a cause of their predetermined structure.

There is a third level of protein structure called tertiary structure, and tertiary structure just refers to a higher order of folding within a polypeptide chain.

Now, any protein that's made up of a single polypeptide is only going to have primary structure, secondary structure and tertiary structure, but if we're dealing with something like hemoglobin, …

Tertiary structure: A protein’s tertiary structure refers to the overall 3D shape of a single protein molecule, formed by the folding of the secondary structures.

Below we delve more into the interactions that stabilize the tertiary structure (overall fold) and quaternary structure (interactions between subunits) of proteins.

The tertiary structure of a native conformation refers to the three dimensional organization of all the atoms—including side chain atoms—in a protein. Perhaps the best way to visualize what …

Then you have tertiary structure, which just talks about the overall 3D structure of a single protein molecule. And this is described by distant interactions between groups within a single protein.

Learn about the four levels of protein structure, including primary, secondary, tertiary, and quaternary structures, in this Khan Academy tutorial.

Different bonds/interactions contribute to the stability of each level of protein structure. Let's explore some common ones such as peptide bonds, hydrogen bonds, and disulfide bonds.