Question

how is the structure of hemoglobin related to its function??

Answer 1

There are two alpha subunits and two beta subunits in a Hemoglobin protein. A central heme group is present in each subunit. The central  central heme group have iron and one oxygen molecule can bind to it. Thus total four oxygen molecules (one to each subunit) can bind to one hemoglobin molecule. Second and third oxygen binds to hemoglobin faster as compared to first and fourt oxygen because of conformational changes induced by oxygen binding. At deoxygenated state, central heme group have a domed-shaped configuration. After oxygenation, it become takes planar configuration. This dome-planar configuration change plays an important role in oxygen binding. Haemoglobin found in arterial circulation, shows very low affinity to carbon dioxide and high affinity to oxygen.