Final answer:
The correct answer to the question is (b) Tertiary; quaternary, indicating that hemoglobin subunits and myoglobin share similar tertiary structure but different quaternary structures.
Step-by-step explanation:
The individual hemoglobin subunits and myoglobin share similar tertiary structure but have rather different quaternary structure. The correct answer would be (b) Tertiary; quaternary. Hemoglobin has a quaternary structure consisting of four subunits that bind together, whereas myoglobin, having a single subunit, lacks a quaternary structure altogether.
Hemoglobin, found in red blood cells, carries oxygen throughout the body thanks to this complex structure. Each subunit in hemoglobin has one iron ion, and changes in the iron's oxidation state allow the binding and release of oxygen. In contrast, myoglobin, which only has a single iron ion per molecule, serves as an oxygen buffer and reservoir, but does not have the multiple subunit interactions present in hemoglobin.
The tertiary structure of a protein includes its overall three-dimensional shape, consisting of the folds and helices formed by the amino acid chain. This level of structure is similar in both hemoglobin and myoglobin subunits. The quaternary structure involves the interaction and orientation of multiple protein subunits, as seen in hemoglobin with its two alpha and two beta subunits, but not applicable to myoglobin because it is made up of a single protein chain.