Haemoglobin is a protein present in blood and helps in transportation of oxygen. It is made up of four chains, two alpha and two beta chains. Myoglobin is another protein similar to haemoglobin. It is present in muscle cells and helps in storage of oxygen. Identify the correct structures of haemoglobin and myoglobin respectively:

Explanation

Haemoglobin has a quaternary structure because it is composed of four protein chains (two alpha chains and two beta chains) that interact and assemble to form the functional haemoglobin molecule. The arrangement and interactions of these subunits are essential for haemoglobin's oxygen-carrying function. Myoglobin, on the other hand, has a tertiary structure. The tertiary structure refers to the folding of a single polypeptide chain into a three-dimensional structure. Myoglobin consists of a single polypeptide chain that folds upon itself, forming a compact structure that allows it to bind and store oxygen in muscles.