Nutrition Science and Everyday Application - beta v 0.1

314 ALICE CALLAHAN, PHD, HEATHER LEONARD, MED, RDN, AND TAMBERLY POWELL, MS, RDN
3. Tertiary structure – This is the unique three-dimensional shape of a protein,
formed as the different side chains of amino acids chemically interact, either
repelling or attracting each other. Thus, the sequence of amino acids in a protein
directs the protein to fold into a specific, organized shape.
4. Quaternary structure – In some proteins, multiple folded polypeptides called
subunits combine to make one larger functional protein. This is called quaternary
protein structure. The protein hemoglobin is an example of a protein that has
quaternary structure. It is composed of four polypeptides that bond together to
form a functional oxygen carrier.