Adult human haemoglobin consists of four polypeptide subunits (two and two type). This assembly represents which level of protein structure?

Step-by-step solution

Adult human haemoglobin is composed of four polypeptide subunits, specifically two and two chains. The primary structure refers to the linear sequence of amino acids in a polypeptide chain. The secondary structure refers to the local folding of the polypeptide chain into structures such as -helices and -pleated sheets. The tertiary structure is the overall three-dimensional shape of a single polypeptide chain. The quaternary structure is the spatial arrangement and interaction of multiple polypeptide subunits to fo